PFOA

CAS No. not given

96%.

Cheng and Klaassen (2008)

C57BL/6, mice

Male

5/dose.

0 or 40

Propylene glycol:water

i.p.

Single dose

Non-GL study

GLP not stated.

NR

Males:

↑ mRNA of cyp2B10,

3A11 and 4A14 in liver (data only reported in figures).

↑ protein levels of cyp2B and 4A in liver (data only reported in figures).

Recovery not assessed.

Males:

NA / 40*

PFOA increased the expression of Cyp2B10 and 4A14 in mouse liver.

K2

This study investigated if expression of cytochrome P450 is altered by PFOA and PFDA and the regulatory mechanisms involved.

i.p. route of exposure was used.

Only male animals were used.

Study was funded by National Institutes of Health grants.

PFOA (ammonium salt)

CAS No. not given

97%.

Das et al. (2017)

SV129 mice (wild type and PPAR-α null)

Male

4/dose.

0 or 10 m/kg bw/day.

Deionized water,

Gavage,

7 days,

Non-GL study,

GLP not stated.

NR

Males:

↑ absolute and relative liver weight (data only reported in figures).

↑ lipid and TGs (data only reported in figures).

Changes in mRNA related to transport, fatty acid, TG and cholesterol synthesis and omega oxidation.

Recovery not assessed.

Males:

NA / 10

PFOA caused extensive micro and macro-vesicular steatosis in hepatocytes and that the steatosis was associated with increases in the accumulation of TG in the liver.

K2

The study investigated whether structurally-diverse PFAS increased liver TG levels and caused steatosis and investigated mechanisms involved.

Only 4 male animals were used.

Study was funded by US Environmental Protection Agency.

PFOA (ammonium salt)

CAS No. not given

98%.

Elcombe et al. (2010)

SD (CD) rats Male  30/dose.

0 or 300 ppm in diet equivalent to 27**.

Powdered RMI feed,

Diet,

1 day,

Non-GL study,

GLP not stated.

NR

Males (mean ± SD):

↑ hepatic cell proliferation (%): 0.22 ± 0.14 vs 0.74 ± 0.55,

↓ liver DNA concentration (mg DNA/g liver): 2.20 ± 0.26 vs 1.92 ± 0.11,

↑ AST (U/L): 177.70 ± 33.27 vs 132.57 ± 36.79.

↑ protein expression of CYP2B1/2, CYP3A1 and CYPA1: data only provided in figures.

↓ periportal hepatocellular glycogen: grade 1.

Males: 

NA / 27*

The objective of the work was to characterize PFOA-induced hepatomegaly in male rats, particularly with respect to the potential role of PPAR-α -mediated cell proliferation and possible decreased apoptosis.

Clinical chemistry findings were consistent with those associated with PPAR activation, notably decreased serum total cholesterol and triglycerides.

APFO did not increase activities of either ALT or AST, consistent with a lack of histologically identified hepatocellular damage. Histopathology demonstrated that APFO caused hepatocellular glycogen loss, hypertrophy, and hyperplasia. The hypertrophy was characterized by increased cyanide-insensitive palmitoyl CoA oxidation (a marker of peroxisome proliferation) and the induction of cytochrome P450 CYP4A1 (accompanied by smooth endoplasmic reticulum proliferation).

K2

This study investigated the PFOA-induced hepatomegaly in male rats.

Only data from study 1 are presented here but data from study 2 are similar.

Only two dose groups were used i.e. control and single treatment group and only male animals were used.

All authors represent organizations that have a current or former financial interest in ammonium perfluorooctanoate. Some authors are affiliated to 3M Company.

PFOA

CAS No. not given

Purity not given.

Kawashima et al. (1995)

Wistar rats

Male

4/dose.

0, 0.0025, 0.005, 0.01, 0.02 or 0.04% equivalent to 0, 3, 6, 12, 24 or 48**, 

i.p.

5 days,

Non-GL study.

GLP not stated.

NR

Males:

↑ acyl transferase activity (data only reported in figures).

↓ GSH S-transferase (data only reported in figures).

↑ TG (data only reported in figures).

Recovery not assessed.

Males:

NA / 3*

Morphological studies demonstrated that the administration of PFOA resulted in a marked proliferation of peroxisomes in hepatocytes.

PFOA produced tri-acylglycerol and cholesterol accumulation in liver. This seems inconsistent with the marked inductions of both peroxisome proliferation and peroxisomal & oxidation.

K2

This was a comparative study investigating hepatic responses following PFOA and PFDA exposure.

i.p. route of exposure was used.

Only male animals were used.

Study was funded by Ministry of Education, Science and Culture in Japan.

PFNA

CAS No. not given

97%.

Das et al. (2017)

SV129 mice (wild type and PPAR-α null)

Male,

4/dose.

0 or 10 m/kg bw/day

Deionized water.

Gavage.

7 days.

Non-GL study.

GLP not stated.

NR

Males:

↑ absolute and relative liver weight (data only reported in figures).

↑ lipid and TGs in liver (data only reported in figures).

Recovery not assessed.

Males:

NA / 10

PFNA cause steatosis and increases in TG in the PPAR-α null mice indicating that the mechanism of the steatosis is at least partially PPAR-α independent.

K2

The study investigated whether structurally-diverse PFAS increase liver TG levels and cause steatosis and investigate mechanisms involved.

Only 4 male animals were used.

Study was funded by US Environmental Protection Agency.

PFDA

CAS No. not given

Purity not given.

Adinehzadeh et al. (1999)

F-344 rats

Male

4-5.

0, 5, 15 or 25

Propyleneglycol:water

i.p.

Single dose,

Non-GL study,

GLP not stated.

NR

Males:

↑ fatty acyl-Co A oxidase activity (data only reported in figures).

Recovery not assessed.

Males:

NA / 5*

PFDA produces hepatotoxic effects in rats that are dose-dependent in the range 2±50 mg/kg by single injection i.p.

K2

This study hypothesised that the metabolic effects of PFDA on hepatic phosphocholine content are not due to toxicity but demonstrate a distinct response to PFDA treatment.

i.p. route of exposure was used.

Only 4-5 male animals were used.

Study was funded by Air Force Office of Scientific Research, Air Force Systems Command, USA.

PFDA

CAS No. not given

Purity not given.

Adinehzadeh et al. (1999)

F-344 rats

Male

5-6.

0, 15 or 50

Propyleneglycol:water

i.p.

Single dose,

Non-GL study,

GLP not stated.

NR

Males (mean ± SE):

↑ total lipids (mg/g liver): 54.6 ± 4.2 vs 37.1 ± 1.7,

↑ phosphatidylcholine (µmol/g liver): 34.0 ± 3.4 vs 26.5 ± 1.4),

↑ phosphatidylethanolamine:

12.6 ± 1.3 vs 9.6 ± 0.4.

Recovery not assessed.

Males:

NA / 15*

PFDA produces hepatotoxic effects in rats that are dose-dependent in the range by single injection i.p.

PFDA produces similar effects on hepatic phospholipid metabolism at 15 and 50 mg/kg. Such effects are characterized by significant increases in liver phosphatidylcholine and phosphatidylethanolamine content.

K2

This study hypothesised that the metabolic effects of PFDA on hepatic phosphocholine content are not due to toxicity but demonstrated a distinct response to PFDA treatment.

i.p. route of exposure was used.

Only 4-5 male animals were used.

Study was funded by Air Force Office of Scientific Research, Air Force Systems Command, USA.

PFDA

CAS No. not given

96%.

Cheng and Klaassen (2008)

C57BL/6 mice

Male

4/dose.

0, 0.5, 1.0, 10, 20, 40 or 80, Propyleneglycol:water

i.p.

Single dose,

Non-GL study,

GLP not stated.

NR

Males:

↑ mRNA of cyp4A14 (data only reported in figures).

Recovery not assessed.

Males:

1 / 10*

Relatively low doses of PFDA activates PPAR-α, and thus increases Cyp4A14 expression. In contrast, at high doses. (>10mg/kg), PFDA activates both CAR and PPAR-α nuclear receptors, and increases the expression of Cyp2B10 and 4A14, respectively. Therefore, PPAR-α and CAR play central roles in regulating mouse Cyps by PFDA.

K2

This study investigated if expression of cytochrome P450 was altered by PFOA and PFDA and the regulatory mechanisms involved.

i.p. route of exposure was used.

Only male animals were used.

Study was funded by National Institutes of Health grants.

PFDA

CAS No. not given

96%.

Cheng and Klaassen (2008)

C57BL/6 mice

Male

5/dose.

0 or 80

Propyleneglycol:water

i.p.

Single dose,

Non-GL study,

GLP not stated.

NR

Males:

↑ mRNA of Cyp2B10,

3A11 and 4A14

↑ protein levels of Cyp2B and 4A (data only reported in figures).

Recovery not assessed.

Males:

NA / 80*

PFDA increases the expression of Cyp2B10 and 4A14 in mouse liver.

K2

This study investigated if expression of cytochrome P450 is altered by PFOA and PFDA and the regulatory mechanisms involved.

i.p. route of exposure was used.

Only male animals were used.

Study was funded by National Institutes of Health grants.

PFDA

CAS No. not given

Purity not given.

Kawashima et al. (1995)  

Wistar rats

Male

4/dose.

0, 0.00125, 0.0025, 0.005 or 0.01% equivalent to 0, 1.5, 3, 6 or 12**,

i.p.

5 days.

NR

Males:

↑ relative liver weight (data only reported in figures)

↑ acyltranserase activity (data only reported in figures)

↑ TG (data only reported in figures).

Recovery not assessed.

Males:

NA / 1.5*

Morphological studies demonstrated that the administration of PFDA resulted in a marked proliferation of peroxisomes in hepatocytes.

PFDA produced triacylglycerol and cholesterol accumulation in liver. This seems inconsistent with the marked inductions of both peroxisome proliferation and peroxisomal & oxidation. These findings suggest that the pattern of toxicity produced by PFDA differs from that produced by PFOA, and that PFDA is more toxic to hepatocytes than PFOA.

K2

This was a comparative study investigating hepatic responses following PFOA and PFDA exposure.

i.p. route of exposure was used.

Only male animals were used.

Study was funded by Ministry of Education, Science and Culture, Japan.

Substance / CAS no. / purity / reference

Strain & species / sex / no. of animals

Dose (mg/kg bw/day) / vehicle / route of admin / duration / Guideline (GL) study / Good Laboratory Practice (GLP) status

PFAS concentration (µg/mL / µg/g)

Observed effects at LOAEL (controls vs treated groups).

Recovery (controls vs treated groups).

Published NOAEL / LOAEL (mg/kg bw/day)

Study author conclusions

Comments

PFOS (potassium salt)

CAS no. Not given

86.9%.

Chang et al. (2017)

Cynomolgus monkeys.

Male and female

6/sex/dose.

Group 1 and 2: 0 or 9

0.5% Tween® 20 + 5% absolute ethanol in water.

Gavage

Single dose, animals not sacrificed,

Non-GL study,

GLP not stated.

Recovery period:

294 days.

At 9 mg/kg bw in males on day 113 (mean ± SD)

Serum: 67.7 ± 7.5.

At 9 mg/kg bw in males on day 420,

Serum: 14.1 ± 2.0

Liver: 7.8 ± 5.5.

At 9 mg/kg bw in females on day 113

Serum: 68.8 ± 2.5.

At 9 mg/kg bw/day in females on day 420

Serum: 9.5 ± 4.4

Liver: 8.3 ± 3.3.

Males:

No adverse effects in liver reported.

Females:

No adverse effects in liver reported.

Recovery:

No adverse effects in liver reported.

Males:

9 / NA*

Females:

9 / NA*

Recovery

Males: 9 / NA*

Females: 9 / NA*

There were no treatment related

changes in serum liver enzymes during the study.

K2

This study examined the effects of orally administered PFOS on hepatic clinical chemistry in Cynomolgus monkeys.

Only two dose groups were used i.e., control and single treatment group.

PFOS was of low purity with impurities including 3.2% PFHxS, 1.2% PFHpS, 1.1% PFPeS, 0.97% PFBS and 0.74% PFPS.

Data for clinical chemistry not presented or discussed in text.

The study was supported by 3M Company. Authors are employees, former employees or consultants of the 3M Company.

PFOS (potassium salt)

CAS no. Not given

86.9%.

Chang et al. (2017)

Cynomolgus monkeys,

Male and female,

4-6/sex/dose.

Group 1 and 3:

0, 14, 14.8 / 17.2 (male/female) and 11

0.5% Tween 20 + 5% EtoH.

Gavage,

Single doses on days 43, 288 and 358, animals not sacrificed,

Non-GL study

GLP not stated.

Recovery period:

294 days.

At 14 mg/kg bw/day in males on day 50 (mean ± SD)

Serum: 104.8 ± 5.2.

At 14 mg/kg bw/day in females on day 50

Serum: 96.5 ± 6.2.

At 14.8/17.2 bw/day in males on day 295

Serum:141.0 ± 13.1.

At 14.8/17.2 bw/day in females on day 295

Serum: 147.6 ± 17.5.

At 11 mg/kg bw in males on day 365

Serum:160.8 ± 14.2.

At 11 mg/kg bw in females on day 365

Serum: 165.0 ± 6.7.

At study termination in males on day 420

Serum: 130.5 ± 14.7

Liver: 94.5 ± 33.9.

At study termination in females on day 420

Serum: 127.0 ± 4.1

Liver: 112.0 ± 18.7.

Males:

No adverse effects in liver reported.

Females:

No adverse effects in liver reported.

Recovery:

No adverse effects in liver reported.

Males:

14.8 or 17.2 / NA*.

Females: 14.8 or 17.2 / NA*.

Recovery

Males:

14.8 or 17.2 / NA*.

Females: 14.8 or 17.2 / NA*.

There were no treatment related

changes in serum liver enzymes during the study.

K2

This study examined the effects of orally administered PFOS on hepatic clinical chemistry in Cynomolgus monkeys.

Only two dose groups were used i.e., control and single treatment group, with variable dosing of 14, 14.8/17.2 or 11 mg/kg bw/day, varying across treatment days, and between sexes on study day 288 (aiming to achieve serum concentrations ~ 100 µg/ml (on Study Day 43), 150 µg/ml (on Study Day 288), and 170 µg/ml (on Study Day 358).

PFOS was of low purity with impurities including include 3.2% PFHxS, 1.2% PFHpS, 1.1% PFPeS, 0.97% PFBS and 0.74% PFPS.

Data for clinical chemistry not presented or discussed in text.

The study was supported by 3M Company. Authors are employees, former employees or contractors of the 3M Company.

PFBA (ammonium salt)

CAS No. not given

28.9% solution in distilled water.

Butenhoff et al. (2012a)

Sprague-Dawley rats

Male and female

10/sex/dose.

Recovery group:

Male and female

10/sex/dose.

0, 6, 30 or 150 (actual dose 0, 5.3, 25.4 or 130.2).

Milli-Q or Milli-U water

Gavage,

28 days,

Non-GL study,

GLP not stated.

Recovery group:

0, 6, 30 or 150 (actual dose 0, 5.3, 25.4 or 130.2)

3 weeks.

Treatment:

Males (mean ± SD):

At 6 mg/kg bw/day

Serum: 24.65 ± 17.63

Liver: 7.49 ± 4.46.

At 30 mg/kg bw/day

Serum: 38.40 ± 23.15

Liver: 14.72 ± 8.15.

Females:

At 150 mg/lg bw/day:

10.30 ± 4.50.

Recovery:

Males:

At 150 mg/kg bw/day:

Serum: 1.07 ± 0.27

Liver: 0.33±0.10.

Females:

NR.

Males (mean ± SD):

↑ absolute liver weight (g): 8.08 ± 0.73 vs 10.26 ± 1.43,

↑ ALP (IU): 234 ± 51 vs 320 ± 67.

↓ cholesterol (mmol/L): 1.37 ± 0.27 vs 1.09 ± 0.20.

↑ mRNA of Acox, Ugt 1A1 and CYP4A1 in liver (data only reported in figures).

↓ mRNA for Cyp1A1, Ugt 1A6 and Ugt 2A in liver (data only reported in figures).

Females:

No adverse effects reported (NOAEL is highest dose tested).

Recovery:

Males (mean ± SD):

↑ TP (g/L): 64.5 ± 1.7 vs 67.3 ± 1.9.

Absolute liver weight comparable to controls (g): 9.53 ± 1.42 vs 9.15 ± 0.50.

Cholesterol comparable to controls (mmol/L): 1.57 ± 0.34 vs 1.70 ± 0.28.

Females:

No adverse effects reported (NOAEL is highest dose tested).

Males:

6 / 30.

Female:

150 / NA.

Recovery:

Males:

30 / 150*.

Females:

150 / NA*.

Male rats appeared more sensitive than female rats in both the 28-day and 90-day studies. The observed reduced sensitivity of females likely is a result, in part, of the greater elimination rate of PFBA in female rats as compared to males.

Liver hypertrophy was observed in the absence of either clinical or microscopic evidence of liver injury and was fully reversible on cessation of treatment.

The lowering of serum total cholesterol observed in 28-day study at 30 and 150 mg/kg-d likely resulted, at least in part, from events tied to activation of PPAR based on the observation of increased transcription levels of Acox and Cyp4a1 at these dose levels.

K1

This was a comparative study investigating oral toxicity of PFBA and PFOA.

Body weight was not affected at the LOAEL in males or females.

Liver weight and cholesterol in male rats returned to control values after 3 weeks recovery.

Hepatocellular hypertrophy was only seen at the highest dose.

Study was funded by the U.S. Environmental Protection Agency. Authors are affiliated to 3M Company.

PFBA (ammonium salt)

CAS No. not given

28.9% solution in distilled water.

Butenhoff et al. (2012a)

Sprague-Dawley rats

Male and female

10/sex/dose.

Recovery group:

Male and female

7/sex/dose.

0, 1.2, 6 or 30

(actual dose 0, 1.4, 6.9 or 32.4).

Milli-Q or Milli-U water.

Gavage,

90 days,

Non-GL study,

GLP not stated.

Recovery group:

0 and 30 (actual doses, 0 and 32.4),

3 weeks.

At 6 mg/kg bw/day in males after treatment (mean ± SD):

Serum: 13.63 ± 9.12

Liver: 3.07 ± 2.03.

At 30 mg/kg bw/day in males after treatment Serum: 52.22 ± 24.89

Liver: 16.09 ± 9.06.

At 30 mg/kg bw/day in females after treatment Serum:  5.15 ± 3.29

Liver: 0.91 ± 0.55.

At 0 mg/kg bw/day in males after recovery Serum:  <0.01

Liver: <0.05.

At 30 mg/kg bw/day in males after recovery Serum:  <0.01

Liver: <0.05.

Males (mean ± SD):

↑ absolute liver weight (g): 10.92 ± 1.17 vs 13.41 ± 2.01.

↑ ALP (IU): 146 ± 38 vs 193 ± 55.

↓ TP (g/L): 71.4 ± 3.0 vs.67.8 ± 3.0.

↓ bilirubin (µmol/L): 2.8 ± 0.

3 vs 2.2 ± 0.3.

↑ hepatocellular hypertrophy (0 vs 9; 5 minimum and 4 slight).

↑ mRNA of Acox, UGT1A1, CYP4A1, malic enzyme and Por (data only reported in figures).

↓ mRNA for Cyp1A1 in liver (data only reported in figures).

Females:

↓ bilirubin (µmol/L): 3.8 ± 0.6 vs 3.1 ± 0.5.

Recovery:

Males (mean ± SD):

Absolute liver weight comparable to controls (g): 10.67 ± 0.74 vs 11.13 ± 1.79

TP comparable to controls – data not shown.

Bilirubin comparable to controls – data not shown

Hepatocellular hypertrophy comparable to controls (0 vs 0).

Females:

Bilirubin: comparable to controls – data not shown.

Males:

6 / 30.

Female:

30 / NA.

Recovery:

Males:

30 / NA*.

Females:

150 / NA*.

Male rats appeared more sensitive than female rats in both the 28-day and 90-day studies. The observed reduced sensitivity of females likely is a result, in part, of the greater elimination rate of PFBA in female rats as compared to males.

Liver hypertrophy was observed in the absence of either clinical or microscopic evidence of liver injury and was fully reversible on cessation of treatment.

K1

This was a comparative study investigating oral toxicity of PFBA and PFOA.

NOAEL in males is based on increased liver weight that is likely to be adaptive, in the absence of clinical or pathological symptoms.

3 animals in the recovery group were used for ocular parameters hence only 7 animals were used for other parameters.

Study was funded by the U.S. Environmental Protection Agency. Authors are affiliated to 3M Company.

PFBA

CAS No. not given

Purity not given.

Foreman et al. (2009)

SV/129 mice (WT, PPAR-α null and humanised. PPAR-α)

Male, 

10/dose.

0, 35, 175 or 350,

Water,

Gavage,

28 days,

Non-GL study,

GLP not stated.

Data only reported in figures.

WT (mean ± SEM)

↑ relative liver weight (Data only reported in figures).

↑ Hepatocyte hypertrophy (total): 0 vs 10.

↑ ALT (U/L): 5.29 ± 3.38.

↑ hepatic replicative DNA. synthesis: 1.8 ± 0.6 vs 19.1 ± 11.7.

↑ mRNA of Cyp4A10 (Data only reported in figures).

↑ mRNA of ACO (Data only reported in figures).

Recovery not assessed.

Males:

NA / 35*

Administration of PFBA caused a PPAR-α–dependent increase in average liver weight and hepatocyte hypertrophy because these changes were found in wild-type mice but not in similarly treated PPAR-α null mice. The relative increase in liver weight and hepatocyte hypertrophy was also observed in humanized PPAR-α mice.

K2

This study investigated if PPAR-α modulates the hepatic response to PFBA exposure and if there is a species difference in PPAR-α activities so used WT, PPAR-α null and humanised PPAR-α mice

Only wild-type data presented in this report.

Only male animals were used.

Study was funded by 3M.

PFHxA

CAS No. not given

98.5%.

Chengelis et al. (2009)

Sprague-Dawley rats

Male and female

10/sex/dose.

0, 10, 50 or 200,

Deionized water,

Gavage,

90 days,

Non-GL study,

GLP not stated.

Recovery group:

0 and 200,

28 days.

NR

Males (mean ± SD):

↓ body weight: data only provided in figures.

↓ cholesterol (mg/dL): 57 ± 12.5 vs 42 ± 9.4.

Females:

No adverse effects reported (NOAEL is highest dose tested).

Recovery:

Data not presented as animals only treated with 200 mg/kg bw/day and not 50 mg/kg bw/day (LOAEL).

Males:

10 / 50.

Females:

200 / NA*.

Effects seen typically suggest an impact on the liver, but the only histologic change in the liver was hepatocellular hypertrophy. This histologic change is considered an adaptive change and is not associated with the serum chemistry changes identified. In the absence of any correlating target organ changes, these slight clinical chemistry changes, while possibly related to PFHxA treatment, are of questionable toxicological significance.

K1

This study investigated the subchronic oral toxicity of PFHxA in rats following previous papers that showed PFHxA does not bioaccumulate and does not show a sex difference.

There were no treatment-related clinical observations or changes in organ weights or clinical chemistry apart from a decrease in cholesterol.

Decreases in body weight, whilst significantly different to controls at 50 mg/kg bw/day, did not show a dose response. The recovery group only consisted of animals treated with 0 or 200 mg/kg bw/day so no data are available regarding the reversibility of body weight at the LOAEL.

Authors are affiliated to AGC Chemicals. Study funding was not reported.

PFHxA

(sodium salt)
CAS No. 2923-26-4

100%.

Loveless et al. (2009)

Crl:CD Sprague-Dawley rats.

Male and female. 10/sex/dose.

0, 20, 100 or 500,

NANOpure® water.

Gavage.

92 days.

OECD 408.

GLP not stated.

Recovery group:

0 and 200.

10/sex/dose.

30 and 90 days.

NR

Males (mean ± SD):

↑ ALT (U/L): 27 ± 5 vs 63 ± 64.

Females: No adverse effects reported (NOAEL is highest dose tested).

Recovery:

Data not presented as animals only treated with 200 mg/kg bw/day and not 20 mg/kg bw/day (LOAEL).

Males:

NA / 20*.

Females:

500 / NA*.

Statistically significant differences from controls were observed for a number of parameters (e.g., AST, ALT, bilirubin, TP), particularly in males dosed with 500mg/kg, but these changes were considered non-adverse for a variety of reasons. Some of these reasons included low incidence, not occurring in a dose–response fashion, direction of change not associated with adversity, or the changes reflected adaptive responses following effects on the liver.

K1

The objective of this study was to investigate acute, repeat dose subchronic, one-generation reproduction, developmental toxicity of PFHxA.

The increase in ALT seen at the lowest dose tested is considered to be non-adverse and was comparable to controls after recovery. Other effects are seen at higher doses but are also considered to be non-adverse.

All authors are affiliated to the DuPont Company. Study funding was not reported.

PFHxA

Cas No. 307-24-4

>99%.

NTP. (2022b)

Sprague-Dawley rats

Male and female 10/sex/dose.

0, 62.6, 125, 250, 500 or 1000 (half doses administered twice daily).

Tween® 80 in deionized water,

Gavage,

28 days,

NTP protocol,

GLP study (FDA GLP, Regs).

At 0 mg/kg bw/day in males (mean ± SE)

Plasma: <LOD

Liver: <LOD.

At 62.6 mg/kg bw/day in males.

Plasma: 0.378 ± 0.178

Liver: <LOD.

At 0 mg/kg bw/day in females.

Plasma: <LOD.

Liver: not measured.

At 62.6 mg/kg bw/day in females.

Plasma: 0.129 ± 0.016.

Liver: not measured.

Males (mean ± SE):

↓ cholesterol (mg/dL): 126 ± 4 vs 101 ± 4.

↑ gene expression of Acox1:

↑ gene expression of Cyp4a1: 1.03 ± 0.09 vs 2.81 ± 0.33.

↑ gene expression of Cyp2b1: 1.29 ± 0.35 vs 2.65 ± 0.32.

↑ gene expression of Cyp2b2: 1.16 ± 0.20 vs 2.22 ± 0.25.

Females:

↑ gene expression of Cyp2b1: 1.83 ± 0.62 vs 4.66 ± 1.22.

↑ gene expression of Cyp2b2: 1.95 ± 0.72 vs 6.32 ± 1.32.

Recovery not assessed.

Males:

NA / 62.6*.

Females:

NA / 62.6*.

A major target organ of toxicity for PFHxA was the liver. Cyp2b1/Cyp2b2 activation indicates CAR-mediated activity, and Acox1/Cyp4a1 activation suggests PPAR-α activity.

PFHxA is the least potent for Cypinduction. This pattern of potency was also reflective of the changes in liver weight and the occurrences of hepatocellular hypertrophy.

PFAS administration increased the levels of serum biomarkers associated with hepatobiliary injury.

K1

This study investigated toxicity of a number of PFAS, including PFHxA, following a 28-day exposure.

No treatment-related clinical observations were reported. Decreased body weight and changes in liver weight and clinical chemistry, apart from cholesterol, were only seen at higher doses.

PFHxA concentrations in liver were only measured in males and were only quantifiable in the 250-1000 mg/kg bw/day dose groups.

Government funded study. Study was audited retrospectively by an independent QA contractor.

PFOA

CAS No. not given

96%.

Botelho et al. (2015)

C57BL/6, mice,

Male,

4/dose.

0, 0.002, 0.005, 0.01 or 0.02% equivalent to 2.4, 6, 12 or 24**.

Water,

Diet,

10 days,

Non-GL study,

GLP not stated.

NR

Males (mean ± SE):

↑ relative liver weight (g): 5.04 ± 0.20 vs 7.84 ± 0.22.

↑ Hypertrophy of centrilobular hepatocytes: data only shown in figures.

Recovery not assessed.

Males:

NA / 2.4*

The production of complement products in the liver can trigger the release of inflammatory mediators, which may eventually lead to enhanced susceptibility to complement-mediated toxicity (as evidenced by increases in ALT, AST and bilirubin. This suggests the role of complement in liver damage following exposure to PFOA.

K2

The study hypothesized that exposure to PFOA exerts adverse effects on the activities of the complement system and that these effects play a role in the hepatotoxicity caused by PFOA.

Only male animals were used.

Apart from increased liver weight and hypertrophy, other liver effects cited by the author were only seen at the highest dose.

Study was funded by 3M Company

PFOA (ammonium salt)

CAS No. not given

97.99%.

Butenhoff et al. (2012a)

Sprague-Dawley rats

Male and female.

10-20/sex/dose.

Recovery group:

Male and female

10/sex/dose.

0 or 30 (actual dose 0 or 27.8).

Milli-Q or Milli-U water.

Gavage,

28 days,

Non-GL study,

GLP not stated.

Recovery group:

0 or 30,

3 weeks.

At 30 mg/kg bw/day in males at end of treatment (mean ± SD)

Serum: 145.60 ± 28.25

Liver: 166.10 ± 28.45.

At 30 mg/kg bw/day in males at end of recovery.

Serum: 14.67 ± 5.30

Liver:  16.32 ± 6.69.

At 30 mg/kg bw/day in females at end of treatment.

Serum: 7.98 ± 4.03

Liver: 11.15 ± 4.91.

At 30 mg/kg bw/day in females at end of recovery:

Serum: 0.03 ± 0.02

Liver: <0.05.

Males (mean ± SD):

↓ body weight gain (g): 357 ±  23 vs 268 ± 26.

↑ absolute liver weight (g): 8.08 ± 0.73 vs 15.54 ± 2.18.

↑ relative liver weight: 2.42 ± 0.17 vs 6.19 ± 0.39.

↑ ALT (IU): 55.8 ± 22.1 vs 66.5 ± 16.2.

↑ ALP (IU): 234 ± 51 vs 320 ± 67.

↑ Urea (mmol/L): 6.3 ± 1.5 vs 9.0 ± 1.5.

↓ TP (g/L): 60.3 ± 3.5 vs 56.2 ± 3.2.

↑ albumin (g/L): 31.3 ± 1.9 vs 33.1 ± 1.7.

↓ food consumption: data NR.

↑ Hepatocellular hypertrophy: 0 vs 10 (1 minimal; 6 slight; 3 moderate).

↑ hepatocellular coagulative necrosis: 0 vs 4 (3 minimal; 1 slight).

↑ mRNA of Acaca, Acox, Cyp4A1, Cyp2B2, Malic, Por, Thrsp, Fasn, Dio1, Ugt1A1, Ugt1A6, Ugt2B and ApoA1: data only shown in figures.

Females (mean ± SD):

↑ ALT (IU): 38.4 ± 8.7 vs 47.4 ± 11.7.

↑ albumin (g/L): 34.4 ± 2.2 vs 36.2 ± 2.0.

↑ mRNA of Acox, Cyp3A1, Malic, Cyp7A1: data only shown in figures.

Recovery:

Males (mean ± SD):

↓ body weight gain (g): 434 ± 36 vs 370 ± 26.

Absolute liver weight comparable to controls (g): 9.57 ± 1.42 vs 9.71 ± 1.16.

↑ relative liver weight: 2.31 ± 0.19 vs 2.77 ± 0.22.

↑ Hepatocellular hypertrophy: 0 vs 4 (minimal).

↑ mRNA of Cyp4A, Malic, Thrsp: data only shown in figures.

Females (mean ± SD):

↑ mRNA of Malic: data only shown in figures.

↑ ALT: data NR.

↓ TP: data NR.

Males:

NA / 30*.

Females:

NA / 30*.

Recovery:

Males:

NA / 30*.

Females:

NA / 30*.

The greater liver weight and hepatocellular hypertrophic response observed in rats treated with NH4+PFOA as compared to those treated with NH4+PFBA correlated with a somewhat greater increase in liver concentrations of mRNA transcripts regulated by PPAR (Acox and Cyp4A1) and an increase in the CAR-regulated Cyp2B2 that was more than 20 times the control.

Although decreased by the end of the recovery period, Cyp4A1 and Cyp2B2 mRNA transcript levels remained elevated in NH4+PFOA-treated males as compared to controls, corresponding to the 20% increase in relative liver weight and 40% incidence of slight hepatocellular hypertrophy observed at the end of recovery.

The 30 mg/kg-d NH4+PFOA dose was included in the design of the 28-day study in order to provide context back to the rather large toxicological database for PFOA.

K2

This was a comparative study investigating oral toxicity of PFBA and PFOA.

As it was a comparative study, only two dose groups i.e. control and single treatment group were used.

Only data for significantly different clinical chemistry parameters were presented in the text.

Study was funded by US EPA. Authors are affiliated to 3M Company.

PFOA (ammonium salt)

CAS No. not given

98%.

Elcombe et al. (2010)

SD (CD) rats Male

30/dose.

0 or 300 ppm in diet equivalent to 27** .

Powdered RMI feed.

Diet,

7 days,

Non-GL study,

GLP not stated.

NR

Males (mean ± SD):

↓ body weight (g): 372 ± 22 vs 328 ± 30 on day 8.

↑ absolute liver weight (g): 15.3 ± 1.3 vs 19.2 ± 3.1 on day 8.

↑ relative liver weight (g/kg): 4.10 ± 0.26 vs 5.83 ± 0.55 on day 8.

↑ hepatic cell proliferation (%):1.42 ± 0.65 vs 5.94 ± 2.12 on day 8.

↓ liver DNA concentration (mg DNA/g liver): 2.07 ± 0.16 vs 1.61 ± 0.28 on day 8.

↓ cholesterol (mmol/L): 2.17 ± 0.25 vs 0.84 ± 0.37 on day 8.

↓ glucose (mmol/L): 19.41 ± 1.79 vs 12.12 ± 2.20 on day 8

↓ TGs: 1.21 ± 0.45 vs 0.30 ± 0.16 on day 8.

↓ periportal hepatocellular glycogen: grade 1.

↑ hepatocellular hypertrophy: grade 1-2 and 3-4.

↑ fatty vacuolation: grade 1-2.

NA / 27*

The objective of the work was to characterize PFOA-induced hepatomegaly in male rats, particularly with respect to the potential role of PPAR-mediated cell proliferation and possible decreased apoptosis.

Clinical chemistry findings were consistent with those associated with PPAR activation, notably decreased serum total cholesterol and triglycerides.

APFO did not increase activities of either ALT or AST, consistent with a lack of histologically identified hepatocellular damage. Histopathology demonstrated that APFO caused hepatocellular glycogen loss, hypertrophy, and hyperplasia. The hypertrophy was characterized by increased cyanide-insensitive palmitoyl CoA oxidation (a marker of peroxisome proliferation) and the induction of cytochrome P450 CYP4A1 (accompanied by smooth endoplasmic reticulum proliferation).

K2

This study investigated the PFOA-induced hepatomegaly in male rats.

Only data from study 1 are presented here but data from study 2 are similar.

Only two dose groups were used i.e. control and single treatment group and only male animals were used.

All authors represent organizations that have a current or former financial interest in ammonium perfluorooctanoate. Some authors are affiliated to 3M Company.

PFOA (ammonium salt)

CAS No. not given

98%.

Elcombe et al. (2010)

SD (CD) rats Male

30/dose.

0 or 300 ppm in diet equivalent to 27**.

Powdered RMI feed.

Diet,

28 days,

Non-GL study,

GLP not stated.

No Data.

Males (mean ± SD):

↓ body weight (g): 462 ± 43 vs 358 ± 53.

↑ absolute liver weight (g): 18.3 ± 2.5 vs 20.8 ± 3.2.

↑ relative liver weight (g/kg): 3.96 ± 0.36 vs 5.83 ± 0.56.

↓ liver DNA concentration (mg DNA/g liver): 1.87 ± 0.16 vs 1.63 ± 0.15.

↑ AST (U/L): 138.35 ± 30.25 vs 112.15 ± 16.29.

↓ cholesterol (mmol/L): 2.04 ± 0.36 vs 1.24 ± 0.27.

↓ glucose (mmol/L): 16.98 ± 1.42 vs 10.56 ± 1.60.

↓ TGs: 1.89 ± 0.60 vs 0.51 ± 0.12.

↓ periportal hepatocellular glycogen: grade 1.

↑ hepatocellular hypertrophy: grade 1-2 and 3-4.

↑ hepatocellular hyperplasia: grade 2.

NA / 27*

Same as above.

K2

Same as above.

PFOA (ammonium salt)

CAS No. 3825-26-1

98%.

Guo et al. (2019)

Balb/c mice Male  12/dose.

0, 0.4, 2 or 10. 

Milli-Q water,

Gavage,

28 days,

Non-GL study,

GLP not stated.

Data only provided in figures.

Males (mean ± SE):

↑ relative liver weight (g): 1.03 ± 0.02 vs 1.68 ± 0.05.

↑ TP (g/L): 57.15 ± 0.68 vs 60.40 ± 0.89.

↑ albumin (g/L): 23.54 ± 0.32 vs 24.06 ± 0.36.

↑ globulin (g/L): 34.60 ± 0.47 vs 36.34 ± 0.63.

↑ hepatocellular hypertrophy: data only provided in figures.

Recovery not assessed.

Males:

NA / 0.4*

After 28 days of exposure, PFO4DA and PFOA exhibited similar toxic mechanisms leading to liver dysfunction, although PFO4DA showed less severity than the same dosage of PFOA. PFO4DA displayed a weaker accumulation potential than PFOA; whereas PFO2HxA and PFO3OA demonstrated no accumulation, and thus did not cause liver injury.

K2

This was a comparative study that compared the hepatotoxicity of PFOA with other new PFSAs.

Results were provided in a supplementary document and didn’t always mirror the methodology section. Overall, PFOA showed similar accumulation and toxicity compared with PFO4DA but was more toxic than PFO2HxA and PFO3OA.

Only male animals were used.

This study was supported by the National Natural Science Foundation of China and Strategic Priority Research Program of the Chinese Academy of Sciences.

PFOA

CAS No. 335-67-1

95%.

Guruge et al. (2006)

Sprague-Dawley rats

Male

6/dose.

0, 1, 3, 5, 10 or 15.

2% Tween® 80.

Gavage.

21 days.

Non-GL study.

GLP not stated.

NR

Males:

↑ expression of genes involved in transport and metabolisms of fatty acids and lipids, cell communication, adhesion, growth, apoptosis, regulation of hormone, proteolysis and peptidolysis and signal transduction: data only provided in figures.

↓ expression of genes involved in apoptosis, regulation of hormone, metabolisms and G-protein coupled receptor protein signalling pathway: data only provided in figures.

Recovery not assessed.

Males:

NA / 1*

The effects seen were dose-dependent with exposure to 10mg PFOA/kg/bw/day causing alteration in expression of the greatest number of genes (over800).

Results showed that a large number of genes associated with lipid or fatty acid metabolism were altered by PFOA and some of the genes were linked with pathways of fatty acid degradation and mitochondrial fatty acid b-oxidation in all concentrations of PFOA-treated rats.

The PFOA induced peroxisomal and mitochondrial fatty acid b-oxidation and the peroxisomal b-oxidation might create oxidative stress on DNA and protein. The reduction of cholesterol synthesis would be consistent with the down-regulation of the gene Hmgcr observed in this study.

The study suggests that the suppression of organic anion transport genes may explain the delayed urinary clearance of PFOA.

There were a number of genes related to tumour progression and inflammation affected by exposure to PFOA, which suggests that exposure to PFOA might enhance the risk of cancer.

K2

This study only looked at gene expression profiles and proposed mechanisms of toxicity.

This research work was partially supported from the Japanese Ministry of Environment under the Global Environment Conservation Research Fund and by a CERG grant from the Hong Kong Research Grants Council.

PFOA (ammonium salt)

CAS No. 3825-26-1

99%.

Kennedy Jr (1987)

Crl:CD-1 mice.

Male and female, 5/sex/dose.

0, 30, 300 and 3000 ppm in diet equivalent to 2.7, 27 or 270**.

Diet,

14 days,

Non-GL study,

GLP not stated.

NR

Males (mean):

↑ absolute liver weight (g): 1.76 vs 4.06.

↑ relative liver weight (g/100g): 5.1 vs 12.3.

Females (mean):

↑ absolute liver weight (g): 1.31 vs 3.35.

↑ relative liver weight (g/100g): 5.0 vs 12.4.

Recovery not assessed.

Males:

NA / 30*

Females:

NA / 30*

Differences in the disposition of ammonium perfluorooctanoate probably are responsible for the differing response seen between male and female rats. Rats excrete the chemical in the urine rather rapidly whereas mice do not. The greater sensitivity of the male compared to the female rat to ammonium perfluorooctanoate is not seen in the mouse. While the retention of this chemical in the blood of mice over time has not been studied, the slower excretion suggests that the residence time in the body is longer than in the rat.

Mice fed 1 ppm ammonium perfluorooctanoate for 14 days showed no increase in liver weight or in the liver-to-body weight ratio. Ammonium perfluorononanoate led to death of mice at feeding concentrations of 300 ppm and liver weight increases at the lowest level tested, 3 ppm. This material appears to be more toxic than ammonium perfluorooctanoate and the liver weight response, in terms of both dose required to produce the change and the magnitude of the liver weight increase, is simiIar.

K2

This was a comparative study with PFOA and other fluorochemicals using liver weight as a means to compare the toxicological response between chemicals.

Only liver weight was measured.

Authors are affiliated to Central Research and Development Department, E.I. du Pont de Nemours and Company, Haskell Laboratory for Toxicology and Industrial Medicine. Study funding was not reported.

PFOA (ammonium salt)

CAS No. 3825-26-1

99%.

Kennedy Jr (1987)

Crl:CD-1 mice.

Male and female, 5/sex/dose.

0, 0.01, 0.03, 0.1, 0.3, 1, 3, 10 or 30 ppm in diet equivalent to 0.0009, 0.0027.0.009, 0.027, 0.09, 0.27, 0.9 or 2.7 **.

Diet,

21 days,

Non-GL study,

GLP not stated.

NR

Males (mean):

↑ absolute liver weight (g): 1.82 vs 2.45.

↑ relative liver weight (g/100g): 5.4 vs 7.1.

Females (mean):

↑ absolute liver weight (g): 1.40 vs 1.85.

↑ relative liver weight (g/100g): 5.2 vs 6.7.

Recovery not assessed.

Males

1 / 3*.

Females:

1 / 3*.

See above.

K2

See above.

PFOA (ammonium salt)

CAS 3825-26-1

>98%.

Li et al. (2019)

C57BL/6 mice.

Male

5/dose.

0 or 1.

Distilled water,

Gavage,

2 weeks,

Non-GL study,

GLP not stated.

NR

Males (mean ± SD):

↑ hepatocyte DNA synthesis: data only provided in figures.

↑ expression of genes related to fatty acid metabolism: cd36, Acox1, Srebf1, Srebf2, Cpt-1α, ApoB.

↑ expression of genes related to nuclear receptors: Cyp4a10, Car, Cyp2b10, Pxr, Cyp3a11.

Recovery not assessed.

Males:

NA / 1*

Pre-existing non-alcoholic fatty liver disease (NAFLD) changed the lipid accumulation effect of PFOA in the liver. Modulation on the lipid metabolism by PFOA might be time-dependent. PFOA increased the expression of Srebf1 and Srebf2 compared to vehicle controls after 2 weeks, regardless of diet. However, such effect diminished at the later time points studied.

K2

The study investigated if the predisposition of NAFLD may enhance the toxicity of PFOA in the liver, and PFOA exposure may change the progression of(NAFLD. Only data for PFOA alone is presented.

Only two dose groups were used i.e. control and single treatment group

ALT and TG were only increased in animals fed a high fat diet and PFOA.

The study was supported in part by Internal Funding to the Klaunig Lab at Indiana University.

PFOA (ammonium salt)

CAS 3825-26-1

>98%.

Li et al. (2019)

C57BL/6 mice

Male

5/dose.

0 or 1.

Distilled water,

Gavage,

8 weeks,

Non-GL study,

GLP not stated.

NR

Males (mean ± SD):

↓ body weight: data only provided in figures.

↑ absolute liver weight: data only provided in figures.

↑ relative liver weight: data only provided in figures.

↑ hepatocyte DNA synthesis: data only provided in figures.

↑ expression of genes related to fatty acid metabolism; Cd36.

↑ expression of genes related to nuclear receptors: Ppar-α, Ppar-γ, Car, Cyp2b10, Pxr, Cyp3a11.

Recovery not assessed.

Males:

NA / 1*

Pre-existing NAFLD changed the lipid accumulation effect of PFOA in the liver. Modulation on the lipid metabolism by PFOA might be time-dependent. PFOA increased the expression of Srebf1 and Srebf2 compared to vehicle controls after 2 weeks, regardless of diet. However, such effect diminished at the later time points studied.

K2

The study investigated if the predisposition of NAFLD may enhance the toxicity of PFOA in the liver, and PFOA exposure may change the progression of NAFLD. Only data for PFOA alone is presented.

Only two dose groups were used i.e. control and single treatment group.

ALT and TG were only increased in animals fed a high fat diet and PFOA.

The study was supported in part by Internal Funding to the Klaunig Lab at Indiana University.

PFOA (ammonium salt)

CAS 3825-26-1

>98%.

Li et al. (2019)

C57BL/6 mice

Male

5/dose.

0 or 1.

Distilled water,

Gavage,

16 weeks,

Non-GL study,

GLP not stated.

NR

Males (mean ± SD):

↑ relative liver weight after 8 weeks: data only provided in figures.

↑ hepatocyte DNA synthesis: data only provided in figures.

↑ expression of genes related to fatty acid metabolism; Cd36, Fasn.

↑ expression of genes related to nuclear receptors: Cyp4a10, Ppar-γ, Car, Cyp2b10, Pxr, Cyp3a11.

Recovery not assessed.

Males:

NA / 1*

Pre-existing NAFLD changed the lipid accumulation effect of PFOA in the liver. Modulation on the lipid metabolism by PFOA might be time-dependent. PFOA increased the expression of Srebf1 and Srebf2 compared to vehicle controls after 2 weeks, regardless of diet. However, such effect diminished at the later time points studied.

K2

The study investigated if the predisposition of NAFLD may enhance the toxicity of PFOA in the liver, and PFOA exposure may change the progression of NAFLD. Only data for PFOA alone is presented.

Only two dose groups were used i.e. control and single treatment group

ALT and TG were only increased in animals fed a high fat diet and PFOA.

The study was supported in part by Internal Funding to the Klaunig Lab at Indiana University.

PFOA

CAS No. 335-67-1

>98%.

NTP. (2022b)

Sprague-Dawley rats.

Male and female. 10/sex/dose.

0, 0.625, 1.25, 2.5, 5 or 10 (males) or 0, 6.25, 12.5, 25, 50 or 100 (females)

2% Tween® 80 in deionized water.

Gavage,

28 days,

NTP protocol,

GLP study.

At 0 mg/kg bw/day in males (mean ± SE)

Plasma: 0.098 ± 0.006

Liver: <LOD.

At 0.625 mg/kg bw/day in males:

Plasma: 50.7 ± 2.2

Liver (ng/mL): 54.6 ± 2.2.

At 0 mg/kg bw/day in females

Plasma: <LOD.

At 0.625 mg/kg bw/day in females:

Plasma: 0.491 ± 0.072.

Males (mean ± SD):

↑ absolute liver weight (g): 12.96 ± 0.41 vs 14.94 ± 0.32.

↑ relative liver weight (mg/g body weight): 37.34 ± 0.72 vs 43.41 ± 0.55.

↑ ALT (IU/L): 57 ± 3 vs 68 ± 3

↑ ALP (IU/L): 207 ± 9 vs 233 ± 8.

↓ TP (g/dL): 6.6 ± 0.1 vs 6.0 ± 0.1.

↓ globulin (g/dL): 2.3 ± 0.1 vs 1.7 ± 0.1.

↑ albumin/globulin ratio: 1.9 ± 0.0 vs 2.5 ± 0.1.

↓ cholesterol (mg/dL): 114 ± 6 vs 72 ± 2.

↓ TG (mg/dL): 138 ± 12 vs 101 ± 8.

↑ hepatocytic cytoplasmic alterations: 0 vs 4 (minimal).

↑ gene expression of Acox1: 1.09 ± 0.14 vs 3.78 ± 0.41.

↑ gene expression of Cyp4a1: 1.07 ± 0.13 vs 22.17 ± 2.17.

↑ gene expression of Cyp2b1: 1.26 ± 0.27 vs 5.75 ± 1.39.

↑ gene expression of Cyp2b2: 1.09 ± 0.15 vs 3.88 ± 0.50.

Females (mean ± SD):

↑ ALP (IU/L): 154 ± 7.

↑ gene expression of Cyp2b1: 1.29 ± 0.21 vs 6.18 ± 1.76.

↑ gene expression of Cyp2b1: 1.42 ± 0.35 vs 5.87 ± 1.68.

Recovery not assessed.

Males:

NA / 0.625.

Females:

NA / 6.25.

A major target organ of toxicity for PFOA was the liver.

Cyp2b1/Cyp2b2 activation indicates CAR-mediated activity, and Acox1/Cyp4a1 activation suggests PPAR-α activity.

PFAS administration increased the levels of serum biomarkers associated with hepatobiliary injury.

K1

This study investigated toxicity of a number of PFAS, including PFHxA, following a 28-day exposure.

No treatment-related clinical observations were reported.

Changes in liver weight and clinical chemistry, apart from ALP, were only seen at higher doses in females. Histopathological changes were only seen at higher doses in both sexes.

Although females were administered a 10-fold higher dose of PFOA, males had a higher plasma concentration compared to females across the dose groups. Liver concentrations of PFOA were measured in males only and increased with dose, but when normalized to dose administered, liver concentrations decreased with increasing dose.

Government funded study. Study was audited retrospectively by an independent QA contractor.

PFOA

CAS No. not given

96%.

Qazi et al. (2010a)

C57BL/6 mice.

Male

4/dose.

0 or 0.002% equivalent to 4**.
Water,

Diet,

10 days,

Non-GL study,

GLP not stated.

At 0 mg/kg bw/day (mean ± SE)

Serum: 0.070 ± 0.004.

At 2.4 mg/kg bw/day

Serum: 87.6 ± 2.1.

Males (mean ± SEM):

↑ liver mass: 6.95 ± 0.42 vs 11.64 ± 0.67.

↑ ALP (µkat/L): 2.42 ± 0.14 vs 3.54 ± 0.16.

↓ cholesterol (mmol/L): 2.34 ± 0.09 vs 1.80 ± 0.11.

↓ TGs (mmol/L): 1.80 ± 0.20 vs 1.15 ± 0.06.

↑ centrilobular hepatocellular hypertrophy, with elevated numbers of cytoplasmic acidophilic granules and occasional mitosis.: data only provided in figures.

↓ TNF-α (ng/mL): 0.43 ± 0.03 vs 0.29 ± 0.04.

↓ INF-γ (ng/mL): 0.65 ± 0.02 vs 0.41 ± 0.03.

↓ IL-4 (ng/mL): 0.13 ± 0.01 vs 0.09 ± 0.01.

↑ granulocytes, myeloid suppressor cells, macrophages, T- helper cells, natural killer cell and presumptive erythrocyte progenitor cells expressing TER119 cells.

Recovery not assessed.

Males:

NA / 4*

PFOA causes histological alterations in the liver and that centrilobular hepatocytes are the main hepatic parenchymal target cells for these fluorochemicals. These hepatocytes, located in zone III of the hepatic acinus, are primarily responsible for the detoxification of toxic compounds as well as being most sensitive to up-regulation of cytochrome P450 and peroxisomal enzymes of fatty acid β-oxidation.

In the histological examination, no sign of necrosis in the livers of PFOA-treated animals. This and the finding that these animals exhibited virtually no change in serum activities of ALT and AST, in combination with a moderate increase in serum ALP, suggest that the doses administered induced hepatomegaly without causing liver damage. Overall, the results demonstrate that exposure of mice to PFOA induces pronounced hypertrophy in centrilobular hepatocytes and alters the hepatic immune status in mice.

K2

This study focussed on histology and immune status of the liver.

Only 4 male animals and only two dose groups were used i.e. control and single treatment group

ALT and AST were unchanged by treatment.

Liver mass is calculated as liver weight (g) / body weight (g) x100

The study was financed by an unrestricted research grant from the 3M Company.

PFOA

CAS No. not given

Purity not given.

Soltani et al. (2023)

C57BL/6J mice.

Male 

5/dose.

0, 1, 5, 10 or 20.

2% Tween® 80.

Gavage,

28 days,

Non-GL study,

GLP not stated.

NR

Males (mean ± SD):

↑ liver weight: data only provided in figures.

↑ AST and ALT: data only provided in figures.

↑ cytokines IL-6, INF-γ and TNF-α: data only provided in figures.

Moderate to severe steatosis and inflammation: data only provided in figures.

Recovery not assessed.

Males: 1 / 5*

It has been shown that PFOA causes tissue changes in the liver by damaging the centrilobular cells of the parenchyma, the main target of fluorochemicals. According to liver weight increase, liver damage and degeneration were seen in all PFOA-treated groups in the current investigation, and normal liver function was compromised, as seen in the group’s pathology slides (PFOA 1, 5, 10, and 20 mg/kg/day). Analysing liver tissue was another indicator of overt liver damage following PFOA exposure, as oxidative stress and inflammatory markers of the liver revealed an increase. Hepatocytes displayed various degrees of alteration, with the high-dose group exhibiting the greatest modifications.

K2

The study investigated the effect symbiotic pre-treatment on PFOA-induced liver damage.

Only data for PFOA alone are presented. 

Only male mice were used.

Study was funded by the Vice Chancellery of Research of Isfahan University of medical Sciences

PFOA (ammonium salt)

CAS No. not given

98%.

Son et al. (2008)

ICR mice. Male

10/dose.

0, 2, 10, 50 or 250 ppm in diet equivalent to 0.49, 2.64, 17.63, 47.21.

Deionized water.

Drinking water.

21 days.

Non-GL study.

GLP not stated.

NR

Males (mean ± SE):

↑ liver weight/body weight ratio (g/100g): 5.05 ± 0.10 vs 6.43 ± 0.18.

Mild lymphocytic infiltration around the central vein.

Recovery not assessed.

Males:

NA / 0.49*

An inflammatory reaction in the liver after PFOA treatment was expected. However, no remarkable inflammatory reaction in the liver of PFOA-treated mice was detected. Considering the decrease of gene expression of TNF-α along with the increase of hepatotoxicity in PFOA-treated mice in our experiments, PFOA may cause hepatotoxicity via decreasing TNF- α by means of impeding the liver tissue repair. Overall, the study showed that PFOA induced hepatotoxicity.

K2

This study investigate liver toxicity following PFOA exposure via drinking water.

ALT, AST, hepatic cytokines and body weight gain were only affected at higher doses.

Study was funded by a grant from the National Fisheries Research and Development Institute (NFRDI), Korea.

PFOA

CAS No. not given

98%.

Wu et al. (2018)

Kunming mice.

Male

8/dose.

0, 1 or 5.

Peanut oil and DMSO,

Gavage,

21 days,

Non-GL study,

GLP not stated.

NR

Males:

↑ liver mass and liver index: data only provided in figures. ↑ GPT and GOT: data only provided in figures.

↑ TG: data only provided in figures.

↓ FGF21 protein: data only provided in figures.

↑ visible vacuoles around liver portal area: data only provided in figures.

↑ CD36-positive cells: data only provided in figures.

↓ ApoB-labelled cells: data only provided in figures.

Recovery not assessed.

Males:

1 / 5

Authors noted that the current data suggested that PFOA-dosed mice resulted in the potential trend of body weights implying PFOA-induced abnormal energy expenditure and utilization. Liver weights in PFOA-dosed mice were elevated, accompanied with increased liver functional transaminases (GPT, GOT) in serum. Overall, the current observations suggest that immediate PFOA exposure can lead to perturbation of liver metabolism in adult mice via affecting vital hormonal expressions.

K2

The study investigated the biological impact of PFOA exposure on pancreatic islet cells and insulin-sensitive liver cells, as well as the molecular mechanisms involved.

No change in body weight was observed at any dose. Biochemical measurements were limited to GPT and GOT.

Only male animals were used and only two dose groups were used i.e. control and single treatment group

PFOA

CAS No. not given

>98%.

Zou et al. (2015)

Kunming mice.

Male

8/dose.

0 or 10.

Vehicle,

Gavage,

14 days,

Non-GL study,

GLP not stated.

NR

Males (mean ± SD):

↑ AST, ALT, ALP, LDH and TBA: data only provided in figures.

↑ deranged liver architecture, marked oedema, vacuolar degeneration, hepatocellular necrosis, and inflammatory cell infiltration: data only provided in figures.

↑ MDA, H2O2 and 8-OHdG: data only provided in figures

↓ SOD, CAT, CRP, IL-6 and COX-2: data only provided in figures.

↓ nuclear DNA fragmentation: data only provided in figures.

Recovery not assessed.

Males:

NA / 10*

A significant increase in the serum levels of AST, ALT, ALP, LDH and TBA was observed after administration of PFOA.

MDA production, H2O2 generation and 8-OHdG formation significantly increased after exposure to PFOA in the liver of mice. Moreover, the activities of endogenous antioxidants SOD and CAT significantly decreased.

K1

This study investigated the ameliorative effect of quercetin on PFOA-induced liver damage.

Only data for PFOA are presented.

As the study focused on the effects of quercetin, only 1 dose of PFOA was used. No clinical signs were measured.

Only male animals were used.

This study was supported by the National Natural Science Foundation of China and Jiangxi Provincial Education Development

PFNA

CAS No. 375-95-1

>97%.

Fang et al. (2012)

Sprague-Dawley rats,

Male

6/dose.

0, 0.2, 1 or 5.

Water,

Gavage,

14 days,

Non-GL study,

GLP not stated.

NR

↑ glycogen: data only presented in figures.

↑ MDA: data only presented in figures.

↑ H2O2: data only presented in figures.

Recovery not assessed.

Males:

1 / 5

PFNA administration increased the levels of rat serum glucose and hepatic glycogen via altering the expression of the genes related to glucose metabolism and suppressing the hepatic insulin pathway, which suggested that PFNA may be able to induce diabetes in rat. However, exposure of PFNA caused hepatic oxidative stress, which may contribute to the suppression of the insulin pathway and the disruption of hepatic glucose metabolism.

K2

The objective of this investigation was to characterize the specific effects of PFNA on rat hepatic carbohydrate metabolism.

Limited endpoints were measured. Only male animals were used. Data were only presented in figures.

This research was supported by the National Natural Science Foundation of China, Anhui provincial natural science foundation and the Scientific Research Foundation of Suzhou University for Doctor.

PFNA

CAS No. 375-95-1

>97%.

Hadrup et al. (2016)

Wister rats, Male

10/dose.

0, 0.0125, 0.25 or 5.

Corn oil,

Gavage,

14 days,

Non-GL study,

GLP not stated.

At 0.25 mg/kg bw/day

Serum: 29.95.

At 5 mg/kg bw/day

Serum: 602.

Males (mean ± SD):

↓ mRNA of AKR1C1, Ugt 2B15, Cyp2C11, Cyp1A2 and Cyp2B6.

Recovery not assessed.

Males:

0.25 / 5

At high PFNA concentrations, macroscopical and microscopical pathology of the liver as well as decreased body and organ weights showed that this dose is highly toxic to the animals. It is not surprising that the mRNA levels of several enzymes are down-regulated as seen for liver. Hepatotoxicity was noted with various PFAS chemicals. Notably, when these toxic effects occur, CYP1A2, CYP2B6 and CYP2C11 were down-regulated by PFNA, whereas CYP3A23/3A1 corresponding to the human CYP3A4 was up-regulated suggesting that this CYP is upregulated to increase elimination of multiple toxic metabolites and confirming the broad substrate specificity of this enzyme.

K1

The objective of the study was to investigate the effects of PFNA in combination with a mixture of 14 other chemicals.

Only data for PFNA alone are presented.  Limited endpoints were measured.

There were no significant effects caused by PFNA alone.

Study was financially supported by the Ministry of Food, Agriculture and Fisheries of Denmark and the Danish Veterinary and Food Administration.

PFNA

CAS No. 375-95-1

>97%.

NTP. (2022b)

Sprague-Dawley rats.

Male and female. 10/sex/dose.

0, 0.625, 1.25, 2.5, 5 or 10 (males) or 0, 1.56, 3.12, 6.25, 12.5 or 25 (females).

Tween® 80 in deionized water.

Gavage,

28 days,

NTP protocol,

GLP study.

At 0 mg/kg bw/day in males (mean ± SE).

Plasma: 0.055 ± 0.012

Liver: 0.762 ± 0.033.

At 0.625 mg/kg bw/day in males.

Plasma: 56.73 ± 1.88

Liver: 145.50 ± 2.68.

At 0 mg/kg bw/day in females (mean ± SE).

Plasma: 0.098 ± 0.011

Liver: not measured.

At 0.156 mg/kg bw/day in females.

Plasma:26.40 ± 1.09.

Males (mean ± SE):

↑ absolute liver weight (g): 11.73 ± 0.23 vs 13.99 ± 0.33.

↑ relative liver weight (mg/g body weight): 34.14 ± 0.30 vs 42.12 ± 0.58.

↓ TP (g/dL): 6.6 ± 0.0 vs 6.0 ± 0.1.

↓ globulin (g/dL): 2.2 ± 0.0 vs 1.5 ± 0.0.

↑ albumin/globulin ratio: 2.0 ± 0.0 vs 2.9 ± 0.1.

↓ cholesterol (mg/dL): 117 ± 5 vs 86 ± 2.

↓ TGs (mg/dL): 120 ± 9 vs 59 ± 9.

↑ total bile acids (µmol/L): 13.1 ± 2.4 vs 27.6 ± 3.1.

↑ hepatocytic cytoplasmic alterations: 0 vs 10 (minimal).

↑ hepatocyte hypertrophy: 0 vs 7.

↑ gene expression of Acox1: 1.06 ± 0.13 vs 4.33 ± 0.67.

↑ gene expression of Cyp4a1: 1.11 ± 0.16 vs 22.08 ± 4.87.

↑ gene expression of Cyp2b1: 1.40 ± 0.32 vs 9.01 ± 2.13.

↑ gene expression of Cyp2b2: 1.22 ± 0.27 vs 3.85 ± 0.48.

Females (mean ± SE):

↑ absolute liver weight (g): 7.67 ± 0.29 vs 9.30 ± 0.30.

↑ relative liver weight (g): 33.29 ± 0.70 vs 40.30 ± 0.91.

↓ TP (g/dL): 6.3 ± 0.1 vs 6.6 ± 0.1.

↑ albumin (g/dL): 4.4 ± 0.1 vs 4.9 ± 0.1.

↓ globulin (g/dL): 1.9 ± 0.1 vs 1.6 ± 0.1.

↑ albumin/globulin ratio: 2.4 ± 0.1 vs 3.0 ± 0.1.

↑ hepatocytic cytoplasmic alterations: 0 vs 5 (minimal).

↑ gene expression of Acox1: 1.02 ± 0.06 vs 3.12 ± 0.57.

↑ gene expression of Cyp4a1

1.05 ± 0.10 vs 8.08 ± 3.36.

↑ gene expression of Cyp2b1:

2.68 ± 1.37 vs 29.83 ± 9.57.

↑ gene expression of Cyp2b2:

2.06 ± 0.85 vs 14.42 ± 1.50.

Recovery not assessed.

Males:

NA / 0.625.

Females:

NA / 1.56.

A major target organ of toxicity for PFNA was the liver.

Cyp2b1/Cyp2b2 activation indicated CAR-mediated activity, and Acox1/Cyp4a1 activation suggests PPAR-α activity.

PFAS administration increased the levels of serum biomarkers associated with hepatobiliary injury.

K1

This study investigated toxicity of a number of PFAS, including PFHxA, following a 28-day exposure.

No treatment-related clinical observations were reported.

Normalized plasma concentrations were generally five- to ninefold higher in males compared to females (adjusting for the 2.5-fold higher dose compared to males). Liver concentrations (measured in males only) increased with dose, and when normalized to the dose administered, liver concentrations decreased with dose.

Government funded study. Study was audited retrospectively by an independent QA contractor.

PFNA (ammonium salt)

CAS No. 4149-60-4

99%.

Kennedy Jr (1987)

Crl:CD-1 mice.

Male and female. 5/sex/dose.

0, 3, 10, 30, 300 and 3000 ppm in diet equivalent to 0.27, 0.9, 2.7, 9, 27 or 270 **

Diet.

14 days,

Non-GL study,

GLP not stated.

NR

Males (mean):

↑ absolute liver weight (g): 1.77/2.08 vs 3.01.

↑ relative liver weight (g/100g): 5.4/6.0 vs 8.4.

Females (mean):

↑ absolute liver weight (g): 1.37/1.61 vs 2.29.

↑ relative liver weight (g/100g): 5.7/5.7 vs 7.7.

Recovery not assessed.

Males:

NA / 3*.

Females:

NA / 3*.

Ammonium perfluorononanoate led to death of mice at feeding concentrations of 300 ppm and liver weight increases at the lowest level tested, 3 ppm. This material appears to be more toxic than ammonium perfluorooctanoate and the liver weight response, in terms of both dose required to produce the change and the magnitude of the liver weight increase, is similar.

K2

This was a comparative study with PFOA and other fluorochemicals using liver weight as a means to compare the toxicological response between chemicals.

Only liver weight was measured.

Authors are affiliated to Central Research and Development Department, E.I. du Pont de Nemours and Company, Haskell Laboratory for Toxicology and Industrial Medicine. Study funding was not reported.

Substance / CAS no. / purity / reference

Strain & species / sex / no. of animals

Dose (mg/kg bw/day) / vehicle / route of admin / duration / Guideline (GL) study / Good Laboratory Practice (GLP) status

PFAS concentration (µg/mL / µg/g)

Observed effects at LOAEL (controls vs treated groups).

Recovery (controls vs treated groups).

Published NOAEL / LOAEL (mg/kg bw/day)

Study author comments

Comments

PFDA

CAS No. 335-76-2

97.8%.

Frawley et al. (2018)

Sprague-Dawley rats.

Female 8/group.

0, 0.125, 0.25, 0.5, 1 or 2.

Deionized water/2%, Tween 80,

Gavage,

28 days,

Non-GL study,

GLP not stated.

NR

Males (mean ± SE):

↑ relative liver weight (%): 3.42 ± 0.09 vs 3.77 ± 0.10.

Recovery not assessed.

Females:

NA / 0.125

The data suggest that, under conditions that do not induce acute toxicity, exposure to PFDA, a long chain polyfluoroalkylcompound, may induce adverse effects that are consistent with the PFAS class.

K2

This project investigated the hepatotoxicity and immunotoxicity of PFDA due to the structural similarity to other PFAS.

Only liver weight was measured despite the title indicating hepatotoxicity was assessed.

This research was supported by the NIH, National Institute of Environmental Health Sciences, NTP Contract, the NTP Statistical Support Contract, and the NTP Chemistry Support Services Contract.

PFDA

CAS No. 335-76-2

97.8%.

Frawley et al. (2018)

B6C3F1 mice,

Female

8/group.

0, 0.31, 0.625, 1.125, 2.5 or 5. 

Deionized water/2%, Tween 80,

Gavage,

28 days,

Non-GL study,

GLP not stated.

NR

Males (mean ± SE):

↑ absolute liver weight (g): 1.122 ± 0.031 vs 1.42 ± 0.054

↑ relative liver weight (%): 4.83 ± 0.08 vs 5.61 ± 0.06.

Recovery not assessed.

Females: 0.31 / 0.625.

The data suggest that, under conditions that do not induce acute toxicity, exposure to PFDA, a long chain polyfluoroalkylcompound, may induce adverse effects that are consistent with the PFAS class.

K2

This project investigated the hepatotoxicity and immunotoxicity of PFDA due to the structural similarity to other PFAS.

Only liver weight was measured despite the title indicating hepatotoxicity was assessed.

This research was supported by the NIH, National Institute of Environmental Health Sciences, NTP Contract, the NTP Statistical Support Contract, and the NTP Chemistry Support Services Contract.

PFDA

CAS No. 335-76-2

>97%.

NTP. (2022b)

Sprague-Dawley rats.

Male and female. 10/sex/dose.

0, 0.156. 0.312. 0.625. 1.25 or 2.5. 

Tween® 80 in deionized water.

Gavage,

28 days,

NTP protocol,

GLP study.

At 0 mg/kg bw/day in males (mean ± SE).

Plasma: 0.022 ± 0.004

Liver: <LOD.

At 0.156 mg/kg bw/day in males.

Plasma: 8.5 ± 0.6

Liver: 44.7 ± 1.5.

At 0 mg/kg bw/day in females.

Plasma: 0.042 ± 0.017

Liver: not measured.

At 0.156 mg/kg bw/day in females.

Plasma:11.2 ± 0.4.

Males (mean ± SD):

↑ absolute liver weight (g): 11.89 ± 0.51 vs 13.54 ± 0.40.

↑ relative liver weight (g): 35.50 ± 0.97 vs 39.32 ± 0.53.

↓ TP (g/dL): 6.4 ± 0.1 vs 6.2 ± 0.1.

↓ globulin (g/dL): 2.2 ± 0.1 vs 1.9 ± 0.0.

↑ albumin/globulin ratio: 1.9 ± 0.1 vs 2.2 ± 0.1.

↓ cholesterol (mg/dL): 107 ± 5 vs 78 ± 3.

↑ gene expression of Acox1: 1.03 ± 0.10 vs 1.70 ± 0.17.

↑ gene expression of Cyp4a1: 1.04 ± 0.10 vs 10.85 ± 1.11.

↑ gene expression of Cyp2b1: 1.06 ± 0.21 vs 3.33 ± 0.57.

↑ gene expression of Cyp2b2: 1.00 ± 0.13 vs 4.24 ± 0.52.

Females (mean ± SD):

↑ absolute liver weight (g): 7.63 ± 0.28 vs 8.94 ± 0.36.

↑ relative liver weight (g): 33.52 ± 0.75 vs 37.66 ± 0.89.

↑ albumin/globulin ratio: 2.4 ± 0.1 vs 2.8 ± 0.1.

↑ gene expression of Acox1: 1.06 ± 0.12 vs 1.58 ± 0.12.

↑ gene expression of Cyp2b1: 1.44 ± 0.37 vs 14.39 ± 4.01.

↑ gene expression of Cyp2b2: 1.47 ± 0.42 vs 12.28 ± 2.95.

Recovery not assessed.

Males:

NA / 0.156.

Females:

NA / 0.156.

A major target organ of toxicity for PFDA was the liver.

Cyp2b1/Cyp2b2 activation indicates CAR-mediated activity, and Acox1/Cyp4a1 activation suggests PPAR-α activity.

PFHxA is the most potent for Cyp induction.

PFAS administration increased the levels of serum biomarkers associated with hepatobiliary injury.

K1

This study investigated toxicity of a number of PFAS, including PFHxA, following a 28-day exposure.

No treatment-related clinical observations were reported.

Plasma concentrations of PFDA increased with increasing dose in both males and females and were marginally higher in females (30% or less) compared to males across the corresponding dose groups. Liver concentrations of PFDA were measured in males only and increased with dose, but when normalized to dose, liver concentrations decreased with increasing dose.

Government funded study. Study was audited retrospectively by an independent QA contractor.

PFUnDA

CAS No. 2058-94-8

98.5%.

Takahashi et al. (2014)

Crl:CD (SD) rats.

Male and female. 12/sex/dose.

Recovery:

5 males and females.

0, 0.1, 0.3 or 1. 

Corn oil,

Gavage,

42 days (males),

41-46 days (females),

OECD 422,

GLP not stated.

Recovery:

0 or 1,

14 days .

NR

Males (mean ± SD):

↑ relative liver weight (%): 2.88 ± 0.27 vs 3.39 ± 0.16^#.

↓ total cholesterol (mg/dL): 56 ± 14 vs 34 ± 6^#.

↑ albumin/globulin ratio: 0.80 ± 0.07 vs 0.93 ± 0.05^#.

↑ hepatocyte centrilobular hypertrophy: 0 vs 3 (2 minimal; 1 mild).

Females:

↓ total cholesterol (mg/dL): 60 ± 11 vs 41 ± 13^#.

↑ hepatocyte centrilobular hypertrophy: 0 vs 1 (1 minimal).

Recovery:

Data not presented as animals only treated with 200 mg/kg bw/day and not 0.3 mg/kg bw/day (LOAEL).

Males:

0.1  / 0.3.

Females: 

0.1 / 0.3.

Data suggest that the liver is a sensitive target organ as the liver weight increased, centrilobular hypertrophy of hepatocytes was seen in both sexes and focal necrosis and/or diffuse vacuolation of hepatocytes was seen at higher doses.

The NOAEL for repeated dose toxicity is 0.1 mg/kg bw/day based on centrilobular hypertrophy of hepatocytes in both sexes at 0.3 mg/kg bw/day.

K1

The study investigated the toxicity of PFUnDA in rats.

The study was carried out according to OECD 422.

^#measured in 5 animals/dose.

Study was funded under the Japanese safety programme for existing chemicals, funded by the Ministry of Health, Labour and Welfare, Japan.

PFDoDA

CAS No. not given

97%.

Kato et al. (2014)

Crl:CD (SD) rats.

Male and female. 12/sex/dose.

Recovery:

5 males and females.

0, 0.1, 0.5 or 2.5. 

Corn oil,

Gavage,

42 days (males),

41-46 days (females),

OECD 422,

GLP not stated.

Recovery:

0 or 1,

14 days.

NR

Males (mean ± SD):

↑ relative liver weight (%): 2.51 ± 0.14 vs 3.00 ± 0.30^#.

↑ ALP (IU/L): 357.2 ± 28.6 vs 551.6 ± 95.2^#.

↓ total cholesterol (mg/dL): 67.0 ± 9.7 vs 40.6 ± 7.8^#.

Females: 

↑ albumin/globulin ratio: 0.92 vs 0.09 vs 1.13 ± 0.08^#.

↑ relative liver weight (%): 3.23 ± 0.19 vs 3.70 ± 0.22^#.

↑ focal necrosis: 0 vs 2 (grade 2).

Recovery:

Data not presented as animals only treated with 200 mg/kg bw/day and not 0.5 mg/kg bw/day (LOAEL).

Males:

0.1 / 0.5.

Females:

0.1 / 0.5.

Data suggested that the liver is a sensitive target organ as various histopathological changes, including hepatocyte hypertrophy

and necrosis, were observed in the liver in both sexes.

The NOAEL for repeated dose toxicity is 0.1 mg/kg bw/day based on centrilobular hypertrophy of hepatocytes in both sexes at 0.5 mg/kg bw/day.

K1

The study investigated the toxicity of PFUnDA in rats.

The study was carried out according to OECD 422.

^#measured in 5 animals/dose.

Study was funded under the Japanese safety programme for existing chemicals, funded by the Ministry of Health, Labour and Welfare, Japan.

PFDoDA

CAS No. 307-55-1

99%.

Zhang et al. (2008)

Sprague-Dawley rats.

Male,

10/dose.

0, 1, 5 or 10.

Gavage,

14 days,

Tween 20,

Non-GL stud,y

GLP not stated.

NR

Males (mean ± SEM):

↑ hepatic SOD activity: data only presented in figures.

↑ mRNA of PPAR-α/g, Acox and CypA4: data only presented in figures.

Recovery not assessed.

Males:

NA / 1*

Rats exposed to low doses of PFDoA exhibited the trend to decrease serum TG and cholesterol, similar to those seen in other PFCAs.

K2

This study investigated if PFDoA exposure has similar effects in the male rat liver as other PFCAs that have shorter carbon lengths, focussing on lipid homeostasis and oxidative stress.

Only male animals were used. Limited endpoints were measured.

Liver weight, TG and cholesterol were only increased at higher doses. Although authors concluded that TG and cholesterol were decreased at low doses, such decreases were only seen at the highest dose and not at the LOAEL.

Funded by the National Natural Science Foundations of China and the Innovation Program of the Chinese Academy of Sciences.

PFTeDA

CAS No. not given

96.5%.

Hirata-Koizumi (2015)

Crl:CD (SD) rats.

Males

and females

7/sex/dose.

Recovery, group:

Males and females,

5/sex/dose.

0, 1, 3 or 10

0.5% water solution of carboxy methylcellulose

sodium.

Gavage,

Males: 42 days beginning 14 days prior mating.

Females: 14 days prior to mating, gestation and to PND5

OECD 422

GLP.

Recovery group:

0 or 10.

Males: 14 days,

Females: 14 days, (recovery group females were not mated).

NR

 No data.

No data.

No data.

 No data.

PFHxDA

CAS No. not given

95.3%.

Crl:CD (SD) rats.

Males

and females

7/sex/dose.

Recovery group:

Males and unmated females

5/sex/dose.

0, 4, 20 or 100

0.5% water solution of carboxymethylcellulose

sodium.

Gavage.

Males: 42 days beginning 14 days prior mating.

Females: 14 days prior to mating, gestation and to PND5

OECD 422

GLP.

Recovery group:

0 or 100.

Males: 14 days.

Females: 14 days (recovery group females were not mated).

NR

Males (mean ± SD):

↑ absolute liver weight (g): 11.95 ± 1.53 vs 14.52 ± 1.82.

↑ relative liver weight (%): 2.41 ± 0.11 vs 2.87 ± 0.23.

↑ centrilobular liver hypertrophy and steatosis: 0 vs 6 (grade 1); 0 vs 2 (grade 2).

Females:

↑ relative liver weight (%): 3.33 ± 0.17 vs 3.70 ± 0.29.

↑ centrilobular liver hypertrophy and steatosis: 0 vs 9 (grade 1).

↑ microgranuloma: 0 vs 7 (grade 2).

Recovery

Males (mean ± SD):

↑ absolute liver weight (g): 13.09 ± 0.95 vs 16.41 ± 0.48.

↑ relative liver weight (%): 2.43 ± 0.15 vs 3.18 ± 0.16.

↑ centrilobular liver hypertrophy and steatosis: 0 vs 2 (grade 1); 0 vs 3 (grade 2).

Females:

↑ relative liver weight (%): 2.40 ± 0.63 vs 2.83 ± 0.27.

Males:

1 / 3.

Females:

3 / 10*.

Recovery

Males:

1 / 3.

Females:

3 / 10*.

The toxic potency of PFCAs was found to become weaker as the carbon chain length increased from C12 to C18 and the toxic potency of PFCAs was considered to be the strongest when the carbon length was C8 to C12.

Considering structural similarities, the gastrointestinal absorption of longer chain PFCAs may be poorer than that of PFCAs with shorter carbon chains.

K2

The study investigated the toxicity of longer chain PFAS.

The study was carried out according to OECD 422.

Funded by the Ministry of Health, Labour and Welfare, Japan, and supported by a Health and Labour Sciences Research Grant from the Ministry of Health, Labour and Welfare, Japan.

PFODA

CAS No. 16517-11-6

98.9%.

Hirata-Koizumi et al. (2012)

Crl:CD (SD) rats.

Male

12/dose.

Recovery

Male and female

5/dose.

0, 40, 200 or 1000.

Carboxymethylcellulose sodium.

Gavage,

42 days (males),

42-56 days (females),

OECD 422,

GLP study.

Recovery group:

0 or 1000.

Males: 14 days,

Females: 14 days, (recovery group females were not mated).

NR

Males (mean ± SD):

↑ absolute liver weight (g): 10.9 ± 1.8 vs 15.8 ± 1.8.

↑ relative liver weight (%): 2.36 ± 0.28 vs 3.35 ± 0.14.

↑ centrilobular hypertrophy: 0 vs 12 (grade 2).

Females (mean ± SD):

↑ relative liver weight (%): 3.32 ± 0.16 vs 3.8 ± 0.10.

Recovery:

Males:

↑ absolute liver weight (g): 11.9 ± 0.3 vs 18.3 ± 2.1.

↑ relative liver weight (%): 2.40 ± 0.06 vs 4.46 ± 0.42.

↑ cenrilobular hypertrophy: 0 vs 4 (grade 2); 0 vs 1 (grade 2).

Females:

 ↑ absolute liver weight (g): 7.8 ± 0.2 vs 10.3 ± 1.2.

↑ relative liver weight (%): 2.4 ± 0.1 vs 3.96 ± 0.53.

PFBS (potassium salt)

CAS no. Not given

98.2%.

Bijland et al. (2011)

APOE*3-Leiden.CETP mice.

Male,

6-8/dose.

0 or 0.03% in diet equivalent to 30.

Diet (vehicle).

Diet,

4-6 weeks,

OECD 407,

GLP not stated.

At 30 mg/kg bw/day at 4-6 weeks (mean ± SD)

Serum: 32.7-37.8 ± 6.6-10.2.

Males:

↓ plasma TG (data only reported in figures).

Altered gene expression related to lipolysis, fatty acid uptake and transport, fatty acid binding and activation, fatty acid oxidation and VLDL assembly.

Recovery not assessed.

Males:

NA / 30

The potency of PFAS to affect lipoprotein metabolism increased with increasing alkyl chain length, with PFBS having negligible effects on hepatic steatosis and hypolipidemia.

K2

This study investigated the mechanism underlying the effect of PFAS on lipoprotein metabolism.

Only two dose groups were used i.e., control and single treatment group and only male animals were used.

The study was funded by the Nutrigenomics Consortium/Top Institute Food and Nutrition; the Netherlands Genomics Initiative; the Netherlands Organization for Health Care Research Medical Sciences); the Netherlands Organization for Scientific Research; the Netherlands Heart Foundation. Authors are affiliated to 3M company.

PFBS (potassium salt)

CAS No. 29420-49-3

98%.

Chen et al. (2022)

C57BL/6 mice.

Male 

6/dose.

0, 10 or 500 µg/l in drinking water equivalent to 2 or 104.

Drinking water (vehicle).

Drinking water.

28 days.

OECD 407.

GLP not stated.

At 2 mg/kg bw/day (mean ± SE)

Liver: 0.017 ± 0.008.

At 104 mg/kg bw/day

Liver: 0.027 ± 0.004.

Males:

↑ apoptosis (data only reported in figures).

↓ CAT activity (data only reported in figures).

Changes in hepatic lipidome (data only reported in figures; 238 lipids changed).

Recovery not assessed.

Males:

2 / 104

Toxicity in mouse liver occurred by inhibiting antioxidant enzyme activity, increasing sphingomyelins and phosphatidylcholines levels, and decreasing phosphatidylinositols levels.

K2

This study examined the potential health risks of low-dose PFBS and PFOS on lipid homeostasis in mouse liver.

Only three dose groups were used i.e., control and two treatment groups and only male animals were used.

This study was supported by the Natural Science Foundation of Jiangsu Province, and the Fundamental Research Funds for the Central Universities, the Research Program of State Key Laboratory of Pollution Control and Resource Reuse, and the Excellent Research Program of Nanjing University.

PFBS (potassium salt)

CAS no. Not given

98.2%.

Lieder et al. (2009a)

CRl:CD (SD) IGS BR VAF/PlusTM rats.

Male and female

10/sex/dose.

0, 60, 200 or 600.

Gavage,

Carboxymethylcellulose

90 days.

OECD 408

GLP study.

NR

Males:

No effects on liver reported.

Females:

No effects on liver reported.

Recovery not assessed.

Males:

600 / NA.

Females:

600 / NA. 

No specific comments on liver toxicity.

K1

This study investigated the toxicity of PFBS following a 90-day exposure.

No liver toxicity was noted.

Authors are affiliated to 3M Company. The 3M Company funded all aspects of the work.

PFBS (potassium salt)

CAS no. Not given

97.9%.

Lieder et al. (2009b)

CRl:CD (SD) IGS BR. VAF/PlusTM rats.

Male and female

30/sex/dose.

0, 30, 100, 300 or 1000

Gavage.

Carboxymethylcellulose

10 weeks.

OECD 416.

GLP not stated.

NR

Males (mean ± SD):

↑ absolute liver weight (g): 19.2 ± 2.4 vs 21.5 ± 2.9.

↑ relative liver weight (%): 3.4 ± 0.3 vs 3.8 ± 0.3.

↑ hepatocellular hypertrophy: 0 vs 3.

Females:

No effects on liver reported.

Recovery not assessed.

Males:

100 / 300.

Females:

1000 / NA*.

The F0 paternal NOAEL was 100 mg/kg bw/day due to hepatocellular hypertrophy and liver weight increase.

K1

This study investigated reproductive toxicity of PFBS in a two-generation study.

Liver weight was not measured in females. Limited liver-related endpoints were measured.

Authors are affiliated to 3M Company, a manufacture of PFBS. The funding for the study was provided by 3M Company.

PFBS

CAS No. 29420-49-3

>97%.

NICNAS. (2005)

Sprague-Dawley rats.

Male and female.

10/ sex/dose.

0, 100, 300 or 900.

Gavage,

Carboxymethylcellulose,

28 days,

OECD 407,

GLP study.

Recovery,

0 and 900,

14 days.

NR

Males (mean ± SE):

↑ absolute liver weight: 25% increase (quantitative data not reported).

↑ relative liver weight: 30% increase (quantitative data not reported).

Females:

No effects on liver reported.

Recovery

Liver weight comparable to controls.

Males:

300 / 900.

Females:

900 / NA*.

Liver weight findings were not observed in the recovery animals. These changes appear to be associated with the test material. The biological and toxicological significance of these observations is unclear due to the lack of supportive or histopathological findings. However, the liver and kidney may be seen as the potential target organs for toxicity and suggests liver weight changes are relevant.

K2

This study investigated the toxicity of PFBS following a 28-day exposure. 

Limited data were presented. Despite reservations by the author, the NOAEL was based on increased liver and kidney weight.

The study was funded by Australian Government Department of Health and Ageing, NICNAS.

PFBS

29420-49-3

>98%.

NICNAS. (2005)

Crl:CDv(SD)

IGS BR VAF/Plusv rats.

Male and female,

10/ sex/dose.

0, 60, 200 or 600

Gavage.

Carboxymethylcellulose

90 days,

OECD 408,

GLP study.

NR

Males (mean ± SEM):

No effects on liver reported.

Females:

↑ TP: 7% decrease (quantitative data not reported).

↑ albumin: 10% decrease (quantitative data not reported).

Recovery not assessed.

Males:

600 / NA*.

Females: 200 / 600*.

No specific comments on liver toxicity.

K2

This study investigated the toxicity of PFBS following a 90-day exposure.

Limited data were presented.

The study was funded by Australian Government Department of Health and Ageing, NICNAS.

PFBS

CAS no. 375-73-5

>97%.

NTP. (2022a)

Sprague-Dawley rats.

Male and female.

10/sex/dose.

0, 62.6, 125, 250, 500 or 1000.

Gavage,

2% Tween® 80

28 days,

NTP protocol,

GLP study (FDA GLP Regs).

At 62.6 mg/kg bw/day in males (mean ± SE),

Plasma: 2.2 ± 4.8,

Liver: 1.3 ± 0.2.

At 62.6 mg/kg bw/day in females.

Plasma: 0.2 ± 0.05

Liver: NR.

At 125 mg/kg bw/day in females,

Plasma: 0.31 ± 0.09

Liver: NR.

Males (mean ± SE):

↑ relative liver weight (mg/g body weight): 35.2 ± 0.79 vs 39.90 ± 0.48.

↓ TP (g/dL): 6.6 ± 0.0 vs 6.4 ± 0.1.

↓ globulin (g/dL): 2.3 ± 0.00 2.3 ±0.1.

↓ cholesterol (mg/dL): 133 ± 6 vs 110 ± 4.

↑ gene expression of Cyp4a1: 1.12 ± 0.17 vs 2.83 ± 0.49.

↑ gene expression of Cyp2b1:1.59 ± 0.41 vs 11.66 ± 2.78.

↑ gene expression of Cyp2b2: 1.27 ± 0.25 vs 7.72 ± 1.42.

Females:

↑ relative liver weight (mg/g body weight): 33.83 ± 0.90 vs 36.46 ± 0.50.

↑ gene expression of Cyp4a1:1.10 ± 0.18 vs 1.84 ± 0.29.

↑ gene expression of Cyp2b1: 1.51 ± 0.42 vs 152.85 ± 27.72.

↑ gene expression of Cyp2b2:1.89 ± 0.75 vs 81.44 ± 15.88.

Recovery not assessed.

Males:

NA / 62.6.

Females: 62.6 / 125.

A major target organ for PFBS was the liver.

The organ weight changes in liver appeared to correlate with histopathologic changes observed in the liver.

Hepatocyte hypertrophy observed with PFAS is likely due to the peroxisome proliferation. This is also supported by the elevated Acox1 and Cyp4a1 levels known to be inducible by PPARα agonists. Hepatocyte hypertrophy can also partially be mediated through CAR, because CAR-activated Cyp2b1 is also elevated.

Increases in serum biomarkers associated with hepatobiliary injury were also observed as well as decreases in cholesterol and TG.

K1

This study investigated the toxicity of PFBS following a 28-day exposure.

Liver enzymes were elevated only at higher doses than the LOAEL.

Although authors noted that liver weight changes correlated with hisopathologic changes, results show that hepatocyte hypertrophy occurred at higher doses than the LOAEL.

This study was funded by NTP. The study was audited retrospectively by an independent QA contractor.

PFHxS (potassium salt)

CAS no. Not given

99.98%.

Bijland et al. (2011)

APOE*3-Leiden.CETP mice.

Male,

6-8/dose.

0 or 0.006% in diet equivalent to 6.

Diet (vehicle).

Diet,

4-6 weeks,

OECD 407,

GLP not stated.

At 6 mg/kg bw/day at 4-6 weeks (mean ± SD)

Serum: 188.3-217.6 ± 10.4-31.5.

Males:

↓ plasma TG: data only reported in figures.

↓ free cholesterol: data only reported in figures.

↓ non HDL cholesterol: data only reported in figures.

↓ HDL cholesterol: data only reported in figures.

↑ liver weight: data only reported in figures.

↑ hepatic TG: data only reported in figures.

↓ plasma TG: data only reported in figures.

↓ bile acid excretion: data only reported in figures.

Altered gene expression related to transcription factors, lipolysis, FA uptake and transport, FA binding and activation, FA oxidation, FA/TG synthesis, VLDL assembly, cholesterol synthesis, storage, metabolism and excretion, HDL formation, maturation, remodeling and uptake.

Recovery not assessed.

Males:

NA / 6*

The potency of PFAS to affect lipoprotein metabolism increased with increasing alkyl chain length.

The data suggest that PFHxS reduces plasma TG and total cholesterol mainly by impairing lipoprotein production.

K2

This study investigated the mechanism underlying the effect of PFAS surfactants on lipoprotein metabolism.

Only two dose groups were used i.e., control and single treatment group and only male animals were used.

The study was funded by the Nutrigenomics Consortium/Top Institute Food and Nutrition; the Netherlands Genomics Initiative; the Netherlands Organization for Health Care Research Medical Sciences); the Netherlands Organization for Scientific Research; the Netherlands Heart Foundation.

Authors are affiliated to 3M company.

PFHxS

(potassium salt)

CAS no. Not given

99.98%.

Butenhoff et al. (2009)

Crl:CD®(SD)

IGS BR VAF/Plus® rats.

Male

15 /dose.

0, 0.3, 1, 3 or 10.

Gavage,

Carboxymethylcellulose

42 days,

OECD 422,

GLP not stated.

At 0.3 mg/kg bw/day in F0 males on day 42 (mean ± SE).

Serum: 44.22 ± 12.66

Liver: 43.80 ± 8.07.

Males (mean ± SE):

↓ cholesterol (mg/dL): 57 ± 8 vs 41 ± 11.

Recovery not assessed.

Males:

NA / 0.3

Decreased serum total

cholesterol observed,

occurring at all dose levels. Although not reaching statistical significance until 10 mg/kg bw/day, mean serum triglycerides were

also lower in all treated groups relative to controls. This observation is consistent with cholesterol reduction as a sensitive clinical endpoint for response to the PFHxS

congener, PFOS.

K1

This study investigated potential toxicity of PFHxS on the reproduction and development in male and female SD rats.

Only male animals were used for repeated dosing segment of the OECD 422 study.

While this is a repeat dose with reproductive/developmental toxicity study, results are presented here as they relate to effects (in males only).

The authors are employees of the 3M Company, a former manufacturer of K+PFHxS. 3M supported the work.

PFHxS

(potassium salt)

CAS no. Not given

98.9%.

Chang et al. (2018)

Crl:CD1 mice.

Male

30/dose.

0, 0.3, 1, and 3

Gavage.

0.5% Tween20,

42 days,

OECD 422,

GLP study.

At 0.3 mg/kg bw/day (mean ± SD):

Liver: 25.9 ± 3.5.

Males (mean ± SD):

 ↑ centrilobular hypertrophy: 0 vs 8^#.

Recovery not assessed.

Males:

NA / 0.3

The liver has been identified as a target organ after repeated oral exposures to K+PFHxS. This observation is consistent with prior studies when rodents were exposed to other perfluoroalkyl acids such as PFHxS, PFOS, PFOA, PFNA, and PFDA and, also, in monkeys when treated with PFOS and PFOA.

The increased liver weights and centrilobular hypertrophy can be attributed, in part, to the activation of these specific xenosensor nuclear receptors.

Liver hypertrophy does not necessarily represent liver toxicity, nor is it necessarily a precursor to a particular manifestation of toxicity.

K1

This study investigated the toxicity of PFHxS in CD1 mouse development and reproduction.

Only male animals were used for repeated dosing segment of the OECD 422 study.

While this is a repeat dose with reproductive/developmental toxicity study, results are presented here as they relate to effects (in males only).

Liver mRNA transcripts were only measured at 0 and 3 mg/kg bw/day.

# Histopathology measured in 10/dose.

The authors are current or former employees or consultants of 3M Company, a former manufacturer of PFHxS and the company supporting the work reported on in the article. Authors received an unrestricted gift grant from 3M Company.

PFHxS

(potassium salt)

CAS no. Not given

97%.

Das et al. (2017)

SV129 and PPAR alpha null mice.

Male

4/dose.

0 or 10.

Gavage,

Vehicle not given,

7 days,

Non-GL study,

GLP not stated.

NR

Wild type males (mean ± SE):

↑ relative liver weight: data only reported in figures.

↑ absolute liver weight: data only reported in figures.

↑ liver cell size: data only reported in figures.

↓ DNA content: data only reported in figures.

↑ lipid and TGs in liver: data only reported in figures.

Recovery not assessed.

Males:

NA / 10

Increases in relative and absolute liver weight were seen in wild type and PPARα-null mice.

The increased cell size and decreased DNA content indicate hepatocyte hypertrophy.

K2

This study investigated the effects of perfluoroalkyl-acids on lipid metabolism using male SV129 and PPAR alpha null mice.

Only data for wild type mice are presented.

Only two dose groups were used i.e., control and single treatment group and only male animals were used.

The study was funded by the U.S. Environmental Protection Agency. Reviewed by the National Health and Environmental Effects Research Laboratory and approved for publication. The 3M Company also funded part of the work.

PFHxS

(potassium salt)

CAS no. Not given

98%.

He et al. (2022)

C57BL/6 mice (high fat diet).

Male

10/dose.

0 or 450 µg/l in drinking water equivalent to 60-110.

Drinking water,

Water,

12 weeks,

Non-GL study,

GLP not stated.

NR

Males (mean ± SE):

↑ body weight from week 7: data only reported in figures.

↑ ALT (U/L): 30.812 ± 3.503 vs 43.633 ± 3.568.

↑ LDL-C (mml/L): 2.368 ± 0.089 vs 2.807 ± 0.067.

↑ TG: data only reported in figures.

↑ expression of genes relating to lipid metabolism, inflammation, and fibrosis.

Recovery not assessed.

Males:

NA / 60*

Treatment markedly aggravated hepatic symptoms resembling NAFLD and caused systematic metabolic disorders as well as gut dysbiosis in the obese mice. Key genes of hepatic lipid metabolism, inflammation, and fibrosis were strongly altered.

The data suggest that environmental PFHxS exposure is a tangible risk factor for metabolic diseases such as NAFLD, especially among obese individuals.

K2

The aim of the study was to investigate the effect of low-dose (environmental) exposure on male mice given a high fat diet.

Only two dose groups were used i.e., control and single treatment group and only male animals were used.

This study was funded by the National Natural Science Foundation of China and the Excellent Research Program of Nanjing University.

PFHxS potassium salt

CAS no. 3871-99-6

>98%.

NTP. (2022a)

Sprague-Dawley rats.

Male and female.

10/sex/dose.

0, 0.625, 1.25, 2.5, 5 or 10 (males)

0, 3.12, 6.25, 12.5, 25 or 50 (females).

Gavage,

2% Tween® 80,

28 days.

NTP protocol.

GLP study (FDA GLP Regs).

At 0.625 mg/kg bw/day in males (mean ± SE)

Plasma: 66.76 ± 3.518.

At 1.25 mg/kg bw/day in males.

Plasma: 92.08 ± 3.348.

At 3.12 mg/kg bw/day in females.

Plasma: 37.030 ± 1.651.

Males (mean ± SE):

↑ absolute liver weight (g): 11.36 ± 0.32 vs 12.58 ± 0.25.

↑ relative liver weight (mg/g body weight): 33.77 ± 0.36 vs 36.81 ± 0.39.

↓ cholesterol (mg/dL): 109 ± 4 vs 96 ± 3.

↑ gene expression of Cyp4a1: 1.08 ± 0.14 vs 2.29 ± 0.26.

↑ gene expression of Cyp2b1: 1.10 ± 0.15 vs 3.97 ± 1.08.

↑ gene expression of Cyp2b2: 1.28 ± 0.34 vs 4.22 ± 0.51.

Females:

↑ relative liver weight (mg/g body weight): 31.92 ± 0.68 vs 34.36 ± 0.88.

↑ gene expression of Cyp2b1: 1.14 ± 0.42 vs 4.40 ± 1.22.

↑ gene expression of Cyp2b2: 1.02 ± 0.41 vs 4.26 ± 1.36.

Recovery not assessed.

Males:

0.625 / 1.25

Females:

NA / 3.12

A major target organ for PFHxS was the liver.

The lack of, or minimal, liver response with PFHxS in females was very apparent compared to the other PFAS and likely due to the lack of presumed activation of PPARα.

Liver weights appeared to correlate with histopathologic changes in the liver.

K1

This study investigated toxicity of PFHxS following a 28-day exposure.

Liver enzymes were elevated only at higher doses than the LOAEL.

Although authors noted that liver weight changes correlated with hisopathologic changes, results show that hepatocyte hypertrophy occurred at higher doses than the LOAEL.

This study was funded by NTP. The study was audited retrospectively by an independent QA contractor.

PFOS (potassium salt)

CAS. No. 2795-39-3

86.9%.

Bagley et al. (2017)

SD rats

Males and females.

12/sex/dose.

0 or 100 ppm in diet equivalent to 6 (males) and 6.6 (females).

Diet,

3 weeks,

Non-GL study,

GLP not stated.

NR

Males (mean ± SD):

↓ body weight gain: data only reported in figures.

↑ absolute liver weight (g): 9.3 ± 1.2 vs 16.4 ± 1.6.

↑ relative liver weight: 0.031 ± 0.003 vs 0.057 ± 0.003.

↓ AST (U/L): 69 ± 7.2 vs 58 ± 3.8 on day 2; 89 ± 20.0 vs 64 ± 5.2 on day 9.

↓ ALT (U/L):  29 ± 4.0 vs 26 ± 3.0 on day 2; 32 ± 6.3 vs 28 ± 3.7 on day 9; 63 ± 8.2 vs 62 ± 7.2 on day 16.

↓ TGs (mg/dL): 120 ± 36.6 vs 71 ± 19.3 on day 16; 57 ± 9.3 vs 28 ± 6.3 on day 23.

↓ total bilirubin (mg/dL): 0.1 ± 0.1 vs 0.02 ± 0.04 on day 9;

0.1 ± 0.1 vs 0.3 ± 0.1 on day 23.

↑ hepatic free FA: data only reported in figures.

↑ hepatic TGs: data only reported in figures.

↑ ground-glass cytoplasmic alterations:  0 vs 12.

↑ minimal to moderate microscopic hepatic necrosis: 0 vs 1.

↑ hepatocellular hypertrophy: 0 vs 9.

Females:

↓ body weight from day 11: data only reported in figures.

↓ body weight gain: data only reported in figures.

↑ absolute liver weight (g): 5.9 ± 0.6 vs 7.6 ± 0.6.

↑ relative liver weight: 0.032 ± 0.003 vs 0.047 ± 0.002.

↓ AST

↓ total cholesterol.

↓ LDH

↓ hepatic free FA: data only reported in figures.

↓ hepatic TGs: data only reported in figures.

↑ minimal to moderate microscopic hepatic necrosis: 0 vs 2.

↑ hepatocellular hypertrophy: 0 vs 7.

Males:

NA / 6*.

Females:

NA / 6*.

Dietary 100 ppm PFOS fed to male rats caused hepatic steatosis through an unknown mechanism.

Incidental statistically significant differences were noted in the liver (AST, ALT, ALP, bilirubin (total, indirect and direct), gamma-glutamyl transferase), in male and/or female rats across the evaluated timepoints, but

these values were within the historical reference ranges and

were not considered toxicologically relevant.

K1

This study tested whether

dietary choline supplementation attenuates PFOS-induced hepatic steatosis in rats.

Only two dose groups were used i.e., control and single treatment group.

Unrestricted funding was provided by 3M Company, St Paul, MN, USA, which is a current or former employer of the authors.

PFOS (potassium salt)

CAS. No. 2795-39-3

87.6%.

Bijland et al. (2011)

APOE*3-Leiden.CETP mice.

Male

6-8/dose.

0 or 0.003% in diet equivalent to 3

Diet (vehicle).

Diet,

4-6 weeks,

OECD 407,

GLP not stated.

At 6 mg/kg bw/day at 4-6 weeks (mean ± SD)

Serum: 85.6-124.7 ± 4.2-9.5.

Males:

↑ liver weight: data only reported in figures.

↓ plasma TG: data only reported in figures.

↓ free cholesterol: data only reported in figures.

↓ non HDL cholesterol: data only reported in figures.

↓ HDL cholesterol: data only reported in figures.

↑ hepatic TG: data only reported in figures.

↓ bile acid excretion: data only reported in figures

Altered gene expression related to transcription factors, lipolysis, FA uptake and transport, FA binding and activation, FA oxidation, FA/TG synthesis, VLDL assembly, cholesterol synthesis, storage, metabolism and excretion, HDL formation, maturation, remodeling and uptake.

Recovery not assessed.

Males:

NA / 3*

The potency of PFAS to affect lipoprotein metabolism increased with increasing alkyl chain length.

The data suggest that PFOS reduces plasma TG and total cholesterol mainly by impairing lipoprotein production.

K2

This study investigated the mechanism underlying the effect of PFAS on lipoprotein metabolism.

Only two dose groups were used i.e., control and single treatment group and only male animals were used.

The study was funded by the Nutrigenomics Consortium/Top Institute Food and Nutrition; the Netherlands Genomics Initiative; the Netherlands Organization for Health Care Research Medical Sciences); the Netherlands Organization for Scientific Research; the Netherlands Heart Foundation.

Authors are affiliated to 3M company.

PFOS (potassium salt)

CAS no. Not given

86.9%.

Butenhoff et al. (2012b)

Crl:CD®(SD)

IGS BR rats.

Male and

Female,

60-70/sex

/dose.

Recovery group: 40/dose.

0, 0.5, 2, 5 or 20 ppm in diet equivalent to 0, 0.024, 0.098, 0.242, 0.984 (males) and

0, 0.029, 0.120, 0.299, 1.251 (females).

Diet,

104 weeks,

Non-GL study,

GLP not stated.

Recovery:

20 ppm in diet equivalent to 1.144 (males) or 1.385 (females)

52 weeks treatment followed by control diet to 104 weeks.

At 0.024 mg/kg bw/day in males at week 105 (mean ± SD)

Serum: 1.31 ± 1.30

Liver: 7.83 ± 7.34.

At 0.098 mg/kg bw/day in males at week 105

Serum: 7.60 ± 8.60

Liver: 26.40 ± 20.40.

At 0.024 mg/kg bw/day in females at week 105

Serum: 4.35 ± 2.78

Liver: 12.9 ± 6.81.

At 0.098 mg/kg bw/day in females at week 102 (mean ± SD)

Serum: 20.20 ± 13030.

Liver: 55.10 ± 31.50.

Males:

↑ hepatocellular centrilobular hypertrophy: 0/65 vs 4/55^#.

↑ cystic hepatocellular

degeneration: 5/65 vs 19/55.

Females:

↑ hepatocellular periportal vacuolation: 15/65 vs 22/55.

↓ serum total cholesterol at week 27: data only reported in figures.

Recovery:

Data not presented as animals only treated with 1.144/1.385 mg/kg bw/day and not 0.098 mg/kg bw/day (LOAEL).

Males:

0.024 / 0.098.

Females: 0.024 / 0.098.

Increased liver tumour incidence BMDL10 (diet)

7.9 and 8.0 ppm in males and females respectively.

BMDL10 (serum)

62 and 92 µg/mL in males and females respectively.

Recovery

Males:

NA / 1.144.

Females: 1.385 / NA.

Liver was the principal target of dietary exposure. The liver effects, as evidenced by either serum clinical chemistry or microscopic observations, were largely limited to centrilobular findings of hypertrophy, eosinophilic hepatocytic granules, hepatocytic pigment, hepatocytic vacuolation, and an increase in hepatocellular adenoma in the highest dietary dose group.

There were relatively few statistically significant or otherwise notable differences between the control and treated groups for clinical chemistry results.

The lowering of serum cholesterol is consistent with data from other studies with PFOS and likely represents a treatment-related effect.

K1

This study examined the toxicity and carcinogenicity of chronic (two years) dietary exposure to PFOS in male and female SD rats.

PFOS was of low purity with impurities including 4.73% PFHxS, 0.71% perfluorinated carboxylic acids (C4, C5, and C8), 1.45% metals, 0.59% inorganic fluoride.

Clinical chemistry changes were only largely seen at higher doses.

Limited changes in clinical chemistry were observed at the LOAEL as effects were only seen at higher doses.

^# liver histopathology measured in 55-65males and females/dose.

Authors are employees of 3M Company.

PFOS

(potassium salt)

CAS No. 2795-39-3

98%.

Chen et al. (2022)

C57BL/6 mice.

Male

6/dose.

0 or 500 µg/l in drinking water equivalent to 109. 

Drinking water.

28 days,

OECD 407,

GLP not stated.

At 109 mg/kg bw/day (mean ± SE)

Liver: 10.73 ± 1.19.

Males:

↑ lipid droplets: data only reported in figures.

↑ inflammation and apoptosis: data only reported in figures.

↑ TG: data only reported in figures.

↑ CAT activities (data only reported in figures: 310 lipids changed.

Changes in hepatic lipidome.

Recovery not assessed.

Males:

NA / 109*

PFOS is easier to accumulate in mouse livers than its substitute PFBS, which could be the most important contributor to the difference in toxicity of strength at the same exposure concentration.

PFOS exposure induced toxicity mainly through increasing oxidative damage and accumulation of TG.

K2

This study examined the effects of PFOS on lipid homeostasis in the liver of male C57BL/6 mice.

Only two dose groups were used i.e., control and single treatment group and only male animals were used.

This study was supported by the Natural Science Foundation of Jiangsu Province, and the Fundamental Research Funds for the Central Universities, the Research Program of State Key Laboratory of Pollution Control and Resource Reuse, and the Excellent Research Program of Nanjing University.

PFOS (potassium salt)

CAS no. Not given

86.9%.

Elcombe et al. (2012)

Sprague-Dawley rats.

Male,

10/dose (total 40/dose, 10 sacrificed on days 1, 28, 56 and 84 days post-treatment).

Recovery group: 10/dose.

0, 20 or 100 ppm in diet equivalent to 1.93 or 9.65.

Diet,

7 days,

Non-GL study

GLP not stated.

Recovery:

0, 20 or 100 ppm in diet equivalent to 0, 1.93 or 9.65.

Sacrificed on days 1, 28, 56, and 84.

At 1.93 mg/kg bw/day on day 1 (mean ± SD)
Serum: 39.49 ± 7.76

Liver: 123.92 ± 23.95.

At 1.93 mg/kg bw/day on day 28.
Serum:15.49 ± 1.60
Liver: 44.17 ± 4.36.

At 1.93 mg/kg bw/day on day 56.
Serum:8.03 ± 1.14

Liver: 32.99 ± 4.19.

At 1.93 mg/kg bw/day on day 84.
Serum:4.38 ± 0.72.

Liver: 24.99 ± 1.30.

Males (mean ± SD):

↓ body weight (g): 412.2 ± 46.8 vs 384.8 ± 46.8 on day 21 and 428.2 ± 50.9 vs 397.0 ± 51.4 on day 28. Comparable to controls on day 84.

↑ relative liver weight (%): 4.53 ± 0.29 vs 5.06 ± 0.38 on day 1 and 3.63 ± 0.39 vs 4.09 ±0.51 on day 84.

↑ plasma cholesterol (nmol/L): 2.73 ± 0.44 vs 2.17 ± 0.37 on day 1 and 2.29 ± 0.24 vs 1.61 ± 0.33 on day 28. Comparable to controls on day 84.

↑ DNA in liver (mg DNA/whole liver): 39.10 ± 5.30 vs 3.71 ± 3.74 on day 28 and 43.45 ± 10.91 vs 33.14 ± 5.09 on day 56. Comparable to controls on day 84.

 ↑ CYP450 (nmol P450/mg protein): 0.86 ± 0.12 vs 1.07 ± 0.24 on day 1, 0.65 ± 0.05 vs 0.87 ± 0.17 on day 28 and 0.68 ± 0.14 vs 0.95 ± 0.16 on day 56 and 0.60 ± 0.15 vs 0.80 ± 0.12 on day 84.

↑ hepatocellular hypertrophy: (0/10 vs 8/10 on day 1, 0/10 vs 5/10 on day 28, 0/10 vs 4/10 on day 56 and 0/10 vs 5/10 on day 84.

Males:

NA / 1.93*

Liver-related effects were seen in male rats during an 84-day recovery period following a 7-day dietary exposure. Exposure was sufficient to result in increased relative liver weight and centrilobular hepatocellular hypertrophy. Although many of the hepatic responses observed on the first day of recovery attenuated over the course of the recovery period, minimal-to-mild centrilobular hepatocellular hypertrophy tended to persist.

There were no significant elevations in liver enzymes (ALT or AST) during this study, suggesting absence of overt hepatic toxicity.

K2

This study evaluated the hepatic responses for up to 84 days in male Sprague-Dawley rats following a 7-day exposure to PFOS.

Only three dose groups were used i.e., control and two treatment groups and only male animals were used.

Authors are employed by 3M Company. This study was funded by 3M Company.

PFOS (potassium salt)

CAS no. Not given

98%.

Han et al. (2018b)

Sprague-Dawley rats.

Male,

6/dose.

0, 1 or 10

DMSO (< 0.4%) in corn oil.

Gavage,

28 days,

OECD 407,

GLP not stated.

Data only reported in figures.

Males (mean ± SE):

↑ ALT (U/L): 38.83 ± 4.59 vs 49.86 ± 3.78.

↑ TBA (nmol/L): 10.57 ± 1.20 vs 16.23 ± 0.55.

↑ TNF-α (ng/mL): 3.87 ± 0.40 vs 5.809 ± 0.34.

↑ IL-6 (ng/mL): 2.72 ± 0.13 vs 3.85 ± 0.43.

↑ PCNA positive nuclei: data only reported in figures.

↑ gene expression (PCNA, c-Jun, c-MYC, CydD1): data only reported in figures

Centrilobular hepatocyte hypertrophy: data only reported in figures.

Recovery not assessed.

Males:

NA / 1

The data suggest that PFOS induces Kupffer cell activation, leading to hepatocyte proliferation by through the NF-kB/TNF-ɑ/IL-6-dependent pathway.

K2

This study explored the effect of PFOS on Kupffer cell activation and hepatocyte proliferation in male SD rats.

Only three dose groups were used i.e., control and two treatment groups and only male animals were used.

This work was supported in part by a grant from the National Science and Technology Ministry of China, the National Natural Science Foundation of China, and the Gong-Yi Program of China Ministry of Environmental Protection.

PFOS (potassium salt)

CAS no. Not given

98%.

Han et al. (2018a)

Sprague-Dawley rats.

Male,

6/dose.

0, 1 or 10

DMSO (<0.4%) in corn oil.

Gavage,

28 days,

OECD 407,

GLP not stated.

NR

Males:

↑ ALT: data only reported in figures.

Recovery not assessed.

Males:

NA / 1

The study demonstrated the mechanism of action of PFOS-induced hepatic injury through ROS generation.

K2

This study investigated the effect of PFOS on oxidative stress and apoptosis in the liver of male rats.

Only three dose groups were used i.e., control and two treatment group and only male animals were used.

This work was supported in part by a grant from the National Science and Technology Ministry of China, the National Natural Science Foundation of China, and the Gong-Yi Program of China Ministry of Environmental Protection.

PFOS

(potassium salt)

CAS no. Not given

Purity not given.

Huck et al. (2018)

C47BL6/J mice,

Male,

5/dose.

0 or 0.089,

Diet,

6 weeks,

Non-GL study,

GLP not stated.

NR

Males:

↑ relative liver weight: data only reported in figures.

↑ TG in liver: data only reported in figures.

↓ gene expression of APOA1, APOA2, PEPCK, G6PC: data only reported in figures.

↑ gene expression of SREBF1: data only reported in figures.

↑ expression of CD36 and PPARγ:  data only reported in figures.

Males:

NA / 0.089

PFOS treatment significantly affected expression of lipid trafficking genes to favour steatosis. CD36, the major hepatocyte lipid importer, and PPARγ were induced by PFOS.

K2

This study examined the effects of PFOS on nonalcoholic fatty

liver disease and nonalcoholic steatohepatitis pathogenesis in male C47BL6/J mice.

Only two dose groups were used i.e., control and single treatment group and only male animals were used.

The study was supported by NIH-COBRE, NIEHS Toxicology Training Grant.

PFOS (potassium salt)

CAS No. 2795-39-3

>98%.

Kim et al. (2011)

Sprague-Dawley rats,

Male and female,

12/sex/group.

0, 1.25, 5 or 10

<0.1% DMSO in saline.

Gavage,

28 days,

OECD 407,

GLP not stated.

NR

Males (mean ± SD or SE (not specified)):

↑ relative liver weight: data only reported in figures.

↑ AST (IU/L): 56.8 ± 16.4 vs 89.4 ± 7.7.

↓ TGs (mg/dL): 58.7 ± 34.8 vs 12.9 ± 3.4.

↑ apoptosis: data only reported in figures.

↑ mRNA and protein levels of Cyp4A1: data only reported in figures.

Females:

↓ body weight in females: data only reported in figures

↑ relative liver weight: data only reported in figures

↑ hepatocellular hypertrophy: 0 vs 12.

Recovery not assessed.

Males:

5 / 10*.

Females:

5 / 10*.

PFOS revealed a significant hepatotoxicity in Sprague-Dawley rats at the dose levels of 5 and 10 mg/kg bw/day. However, the response showed an apparent gender difference. PFOS primarily affected liver by inducing apoptotic signals and CYP4A1 expression which might be a potent cause of blood hypolipidemia.

K1

This study explored the effects of low dose PFOS toxicity in male and female rats.

Only male rats at 0 and 10 mg/kg bw/day were investigated for apoptosis in liver and gene expression.

This research was supported by a grant from National Institute of Food and Drug Safety Evaluation, Korea Food and Drug Administration for the Korea National Toxicology Program.

PFOS (potassium salt)

CAS No. 1763-23-1

>96%.

NTP. (2022a)

Sprague-Dawley rats,

Male and female, 10/sex/dose.

0, 0.312, 0.625, 1.25, 2.5 or 5.

2% Tween® 80 in deionized water.

Gavage,

28 days,

OECD 407,

GLP study.

At 3.12 mg/kg bw/day in males (mean ± SE)

Plasma: 23.7 ± 1.1

Liver: 87.2 ± 3.04.

At 3.12 mg/kg bw/day in females.

Plasma: 30.5 ± 0.9

Liver: NR.

Males (mean ± SE):

↑ relative liver weight (mg/g body weight): 34.92 ± 0.22 vs 38.66 ±0.47.

↑ absolute liver weight (g): 11.79 ± 0.29 vs 13.14 ± 0.28.

↓ cholesterol in serum (mg/dL): 115 ± 2 vs 97 ± 3.

↑ gene expression of Cyp4a1: 1.04 ± 0.1 vs 2.09 ± 0.18. 

↑ gene expression of Cyp2b1: 1.17 ± 0.21 vs 5.87 ± 1.05.

↑ gene expression of Cyp2b2: 1.22 ± 0.23 vs 6.60 ± 1.01.

Females (mean ± SE):

↑ relative liver weight (mg/g body weight): 33.56 ± 0.66 vs 36.15 ± 0.54.

↑ absolute liver weight (g): 7.37 ± 0.18 vs 8.26 ± 0.22.

↑ gene expression of Acox1:  1.02 ± 0.06 vs 1.32 ± 0.05.

↑ gene expression of Cyp4a1: 1.03 ± 0.08 vs 1.75 ± 0.12.

↑ gene expression of Cyp2b1: 1.53 ± 0.44 vs 32.47 ± 4.28.

↑ gene expression of Cyp2b2: 1.56 ± 0.47 vs 34.78 ± 6.76.

Recovery not assessed.

Males:

NA / 0.312*

Females:

NA / 0.312*

A major target organ for PFOS was the liver.

PFOS females showed increased liver weights, Cyp2b1 expression, and hepatocellular hypertrophy in the presence of minimal increases in Cyp4a1 expression.

Hepatocyte hypertrophy observed with PFOS is likely due to the peroxisome proliferation. This is also supported by the elevated Acox1 and Cyp4a1 levels known to be inducible by PPARα agonists. Hepatocyte hypertrophy can also partially be mediated through CAR, because CAR-activated Cyp2b1 is also elevated.

K1

This study investigated toxicity of PFOS following a 28-day exposure.

Liver enzymes were elevated only at higher doses than the LOAEL.

This study was funded by NTP. The study was audited retrospectively by an independent QA contractor.

PFOS (potassium salt)

CAS No. 2795-39-3

86.9%.

Seacat et al. (2002)

Cynomolgus monkeys

Male and female

4-6/sex/dose.

Recovery group:

(2/sex/dose).

0, 0.03, 0.15 or 0.75,

Lactose,

Gavage,

182 days,

Non-GL study,

GLP not stated.

Recovery group:

0, 0.15 or 0.75,

1 year.

At 0.15 mg/kg bw/day in males (mean ± SD)

Serum: 86.2 ± 25.2 ppm

Liver: 58.8 ± 19.5 ppm.

At 0.75 mg/kg bw/day in males.

Serum: 173 ± 37 ppm

Liver: 395 ± 24 ppm.

At 0.15 mg/kg bw/day in males.

Serum: 66.8 ± 10.8 ppm

Liver: 69.5 ± 14.9 ppm.

At 0.75 mg/kg bw/day in females.

Serum: 171 ± 22 ppm

Liver: 273 ± 14 ppm.

Males (mean ± SD):

↓ body weight gain (%): 14 ± 11% vs -8 ± 8% on day 182.

↑ mortality (0 vs 2)

↓ total cholesterol from day 91 (mg/dL): 152 ± 28 vs 48 ± 19.

↑ HDL from day 153 (mg/dL): 63 ± 11 vs 13 ± 5.

↑ TG (mg/dL): 45 ± 9 vs 30 ± 12.

↓ total bilirubin from day 91 (mg/dL): 0.6 ± 0.2 vs 0.2 ±0.1

↑ SBA from day 153 (mg/dL): 6 ± 0.8 vs 18 ± 9.

↓ SDH from day 37 (IU/L): 6 ± 4 vs 3 ±1.

↑ centrilobular

vacuolation, hypertrophy, and mild bile stasis: sex and data NR.

↑ lipid-droplet accumulation (no. animals): 0/4 vs 2/2.

Females (mean ± SD):

↓ body weight gain (%): 5 ± 5% vs -4 ± 5% on day 182.

↑ absolute liver weight (g): 51.1 ± 9.4 vs 75.3 ± 0.3 on day 182.

↑ relative liver weight (%): 1.8 ± 0.2 vs 2.9 ± 0.3 on day 182.

↓ total cholesterol from day 91 (mg/dL): 160 ± 47 vs 82 ± 15.

↑ HDL from day 153 (mg/dL): 56 ± 16 vs 21 ± 7.

↓ SDH from day 37 (IU/L): 5 ± 3 vs 3 ± 2.

↓ ALT from day 37 (IU/L): 87 ± 86 vs 44 ± 10.

↑ ALP from day 37 (IU/L): 283 ± 137 vs 316 ± 172

↑ centrilobular.

vacuolation, hypertrophy, and mild bile stasis (sex and data NR).

↑ lipid-droplet accumulation: 0/4 vs 2/4. 

Recovery:

Males:

Cholesterol and HDL returned to control levels.

No data given for bilirubin, SBA, CK and SDH.

Lipid-droplet accumulation, hepatocellular hypertrophy and vacuolation comparable to controls.

Females:

No data given for liver weight

Lipid-droplet accumulation, hepatocellular hypertrophy and vacuolation comparable to controls.

Males:

0.15 / 0.75

Females: 0.15 / 0.75.

Recovery

Males:

0.75 / NA.

Females:

0.75 / NA.

The results of this study indicated lipid accumulation occurred in the liver, without peroxisome proliferation.

The decrease in serum total cholesterol observed in cynomolgus monkeys reported was the earliest reliable measure of clinical response to PFOS. In the case of the 0.03 mg/kg/day males it appeared to be a result of inherently lower cholesterol in these monkeys as compared to control and was not believed to be an effect of treatment.

The recovery group animals revealed that the effects of PFOS on clinical chemistry, hormones, and liver histology are reversible. This reversal was accompanied by significant decreases in serum and liver PFOS.

K1

This study was conducted to determine the earliest measurable

response of primates to low-level PFOS exposure.

PFOS was of low purity with impurities including 8.4% lower chain length homologues of PFOS, 1.4% sodium, 0.6% inorganic fluoride, 0.3% PFOA, 0.3%

PFPeA, 0.1% PFBA.

Authors are affiliated to 3M Company. No details of funding given.

Substance / CAS no. / purity / reference

Strain & species / sex / no. of animals

Dose (mg/kg bw/day) / vehicle / route of admin / duration / Guideline (GL) study / Good Laboratory Practice (GLP) status

PFAS concentration (µg/mL / µg/g)

Observed effects at LOAEL (controls vs treated groups)

Recovery (controls vs treated groups)

Published NOAEL / LOAEL (mg/kg bw/day)

Study author comments

Comments

PFBA ammonium salt

CAS No. not given

98%.

Das et al. (2008)

Pregnant CD-1 mice.

Female

5/dose.

Recovery group:

5/dose.

0, 35, 175 or 350,

Water,

Gavage,

GD1-GD17,

Non-GL study,

GLP not stated.

Recovery group:

0, 35, 175 or 350,

GD1-GD18,

PND22.

At 35 mg/kg bw/day (mean ± SE)

Serum: 3.78 ± 1.01

Liver: 1.41 ± 0.42.

At 175 mg/kg bw/day

Serum: 4.44 ± 0.65

Liver: 1.60 ± 0.25.

Maternal effects

↑ liver weight (data only reported in figures).

Recovery:

Maternal effects

Liver weight comparable to controls after 3 weeks (data NR).

Maternal:  

35 / 175*

Recovery:

Maternal:

35 / 175*

Findings reflect a general hepatic response to PFBA in the mouse and also indicate indirectly an effective transplacental transfer of the chemical from the maternal compartment to the foetuses, leading to similar liver enlargement.

K2

The study investigated if PFBA elicited adverse effects similar to PFOS and PFOA in mice.

Limited endpoints related to liver were measured. Expression of ‘hepatic genes’ were not significantly altered in neonatal liver. 

Study was funded by U.S. Environmental Protection Agency.

Substance / CAS no. / purity / reference

Strain & species / sex / no. of animals

Dose (mg/kg bw/day) / vehicle / route of admin / duration / Guideline (GL) study / Good Laboratory Practice (GLP) status

PFAS concentration (µg/mL / µg/g)

Observed effects at LOAEL (controls vs treated groups).

Recovery (controls vs treated groups).

Published NOAEL / LOAEL (mg/kg bw/day)

Study author comments

Comments

PFOA (ammonium salt)

CAS No. 3825-26-1

98.4%.

Xu et al. (2022)

Balb/c mice. Pregnant females. 8/dose.

0 or 1,

Milli Q water,

Gavage,

GD0 to parturition,

Non-GL study,

GLP not stated.

NR

Females (mean ± SD):

↑ absolute and relative liver weight: data only provided in figures.

↑ AST and ALT: data only provided in figures.

Hepatocyte hypertrophy, disarrangement, cytoplasmic loss, nuclear migration, acidophil bodies and inflammatory cell infiltration.

↑ mRNA levels of genes related to inflammation: Tlr4, Myd88, Traf6, Rela, IL1b and Tnf.

↑ apoptosis in liver: protein expression of PARP-1, cleaved caspase-3 and Bax.

Recovery not assessed.

Females:

NA / 1*

Histopathological changes, characterized by enlargement and disarrangement of hepatocytes, cytoplasm loss, nuclear migration, acidophilbodies, inflammatory cell infiltration, and reduction of glycogen storage, were observed in maternal mice in the PFOA exposed groups. Serum ALT and AST were also significantly increased.

Gestational exposure to PFOA induced maternal hepatic alterations through the gut-liver axis.

K2

This was a comparative study investigating the mechanisms of maternal hepatotoxicity between PFOA and GenX.

Only two dose groups were used i.e. control and single treatment group

PFOA

CAS No. not given

99.2%.

Zhang et al. (2021)

Kunming mice. Pregnant females, 10/dose.

0, 1, 5, 10, 20 or 40

Distilled water,

Gavage,

GD1-7,

Non-GL study,

GLP not stated.

NR

Males (mean ± SD):

↑ liver index: data only provided in figures.

↓ SOD and GSH-Px in liver: data only provided in figures

↑ MDA in liver: data only provided in figures.

Recovery not assessed.

Females:

NA / 1*

The present study results suggest that PFOA is hepatotoxic in a dose-dependent manner, and short-term exposure can cause swelling of the liver cells, which explains the increase in liver index.

The higher the PFOA levels administered, the lower the SOD and GSH-Px, and the greater the MDA accumulation. The results suggested that oxidative damage is the potential mechanism of PFOA hepatotoxicity.

K1

This study investigated the mechanism of PFOA toxicity on the liver of mice during early pregnancy.

No change in body weight was reported. Histopathological changes were only seen at the higher doses.

The study was financially supported by the National Natural Science Foundation of China.