Occupational Exposure Limits of lead, dimethylamine, n-butyl-2,3-epoxypropyl ether, and 2-ethyl-1-hexanol and carcinogenicity and occupational sensitizer classification

The Committee for the Recommendation of Occupational Exposure Limits (OELs) of the Japan Society for Occupational Health (JSOH) proposed provisional OELs as reference values for preventing adverse health effects in workers caused by occupational exposure to chemical and physical agents at the 89th Academic Conference on May 25, 2016 held in Fukushima. Lead (CAS No.7439-92-1) is a blue-gray or silvergray soft metal that is present in the electrodes of lead batteries, alloys, leaded glass, anticorrosive pigments, bullets, sound-proofing sheets, radiation shielding, and fine arts and crafts materials. JSOH proposes 0.03 mg/m3 as the OEL-Mean (OEL-M) for lead, corresponding to the revised OEL Based on Biological Monitoring (OEL-B) of 15 μg/100 ml (blood lead), according to two recent epidemiological studies on the relationship between lead present in the air and in blood among workers exposed to relatively low levels' ''. Further revisions will be considered if reproductive toxicity below OEL-B is noticed. The carcinogenicity classification is maintained as group 2B because of insufficient animal evidence, although the International Agency for Research on Cancer (IARC) upgraded lead to group 2A. Oral administration of lead to rodents caused renal cancer, but no carcinogenicity was observed in an inhalation study.