Water Quality Standards

Antimony salts and possibly organic complexes of antimony are typically found in food and water at low levels. Reported concentrations of antimony in drinking-water are usually less than 4 µg/litre. Estimated dietary intake for adults is about 0.02 mg/day. Where antimony–tin solder is beginning to replace lead solder, exposure to antimony may increase in the future. 

In its overall evaluation based on inhalation exposure, IARC concluded that antimony trioxide is possibly carcinogenic to humans (Group 2B) and antimony trisulfide is not classifiable as to its carcinogenicity in humans (Group 3) 

In a limited lifetime study in which rats were exposed to antimony in drinking-water at a single dose level of 0.43 mg/kg of body weight per day, effects observed were decreased longevity and altered blood levels of glucose and cholesterol. No effects were observed on the incidence of benign or malignant tumours.

An uncertainty factor of 500 (100 for inter- and intraspecies variation and 5 for the use of a LOAEL instead of a NOAEL) was applied to the LOAEL of 0.43 mg/kg of body weight per day, giving a TDI of 0.86 µg/kg of body weight. An allocation of 10% of the TDI to drinking-water gives a concentration of 0.003 mg/litre (rounded figure), which is below the limit of practical quantitative analysis. The provisional guideline value for antimony has therefore been set at a practical quantitation level of 0.005 mg/litre. This results in a margin of safety of approximately 250-fold for potential health effects, based on the LOAEL of 0.43 mg/kg of body weight per day observed in the limited lifetime study in rats.