Addendum to Cobalt and cobalt compounds [BAT Value Documentation, 2007

Abstract

Cobalt The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the exposure equivalents for carcinogenic substances (EKA) for cobalt and cobalt compounds in 2006. Available publications are described in detail. Cobalt is potentially carcinogenic and mutagenic and has a sensitizing effect. This metal has an effect on the bronchopulmonary system, the heart and blood. Most of the recent studies on occupational exposure to cobalt contained data on concentrations in air and urine, only in some cases also in blood. As the concentration of cobalt in urine is about 10 times higher than that in blood, the detection of cobalt in urine both diagnostically and analytically is more reliable and the method is not invasive, the EKA between cobalt in air and cobalt in blood is withdrawn. The relationships between the concentration of cobalt in air and that in urine derived from the more recent studies show results that agree with comparable relationships derived in 1989. The Commission therefore retains the correlation already derived in 1986 between the concentration of cobalt in ambient air and that in urine, and extends this to include lower concentrations. The correlation contains air concentrations from 0.01 to 0.5 mg cobalt/m 3 and concentrations of cobalt in urine from 6 to 300 µg/L. The sampling time is at the end of the exposure or shift, for long‐term exposures after several shifts.