Background and scope of discussion

This is a draft position statement for discussion. This does not represent the views of the Committee and should not be cited.

4.               The UKHSA advises the DWI on potential health risks from chemicals in drinking water. Post EU exit, the DWI is reviewing the regulatory standards for some chemicals in drinking water, including antimony. UKHSA sought advice from the COT with respect to an appropriate HBGV for antimony, which would inform the consideration of an appropriate drinking water regulatory limit for antimony.

5.               The COT has previously reviewed the dietary exposure to antimony in infants and young children aged 4 to 18 months as part of the 2014 survey of metals and other elements in infant foods (COT, 2017). The COT has also reviewed dietary exposure to antimony in various population subgroups as part of the 2006 UK Total Diet study of metals and other elements (COT, 2006).  For these reviews, the COT used the WHO TDI of 6 µg/kg bw/day for the evaluation (WHO, 2003).

6.               More recently Health Canada (2024) and ATSDR (2019) have considered antimony and derived lower HBGVs. WHO, ATSDR and Health Canada all derived their HBGVs from the same study (Poon et al., 1998), however, they diverge in their interpretation of the study results and the selection of the NOAEL.

7.               Two antimony discussion papers (TOX/2024/38 and TOX/2025/04) were presented to the COT at the October 2024 and February 2025 meetings respectively. The COT assessed the Poon et al. (1998) study and its interpretations, as well as other available evidence in order to determine an appropriate HBGV to support an update to the antimony drinking water standard in the UK.