Water Quality Standards

Zinc is an essential trace element found in virtually all food and potable water in the form of salts or organic complexes. The diet is normally the principal source of zinc. Although levels of zinc in surface and ground water normally do not exceed 0.01 and 0.05 mg/litre, respectively, concentrations in tapwater can be much higher as a result of dissolution of zinc from pipes.

In 1982, JECFA proposed a provisional maximum tolerable daily intake for zinc of 1 mg/kg of body weight. The daily requirement for adult men is 15–20 mg/day. It was considered that, taking into account recent studies on humans, the derivation of a health-based guideline value is not required at this time. However, drinking-water containing zinc at levels above 3 mg/litre may not be acceptable to consumers (see Acceptability aspects).