ECHA’s Committee for Risk Assessment (RAC) has recently adopted scientific opinions on occupational exposure for 4,4’-methylene-bis-[2-chloroaniline] (MOCA), and for arsenic (As) acid and its inorganic compounds. The critical endpoint for these substances is non-threshold genotoxic carcinogenicity, hence no Occupational Exposure Limit (OEL) could be established. Unit cancer risk values for workers’ exposure by the inhalation route were reported to be 9.65 x 10-6 per µg/m3 (MOCA) and 1.4 x 10-4 per μg As/m3, meaning that lifetime daily exposures to 1.04 μg MOCA/m3 or 0.07 μg As/m3 are equivalent to an excess cancer risk of 1 in 100,000. Analogous values by the dermal route were 3.38 x 10-5 per µg MOCA/kg bw/day and 6.4 x 10-6 per μg As/kg bw/day, equivalent to an excess cancer risk of 1 in 100,000 arising from lifetime doses of 0.29 μg MOCA/kg bw/day or 1.56 μg As/kg bw/day.

European Chemicals Agency (2017). Committee for Risk Assessment (RAC) Opinions on 4,4’-methylene-bis-[2-chloroaniline] (MOCA) and on Arsenic acid and its inorganic salts. Adopted 29 May 2017.


The above items were taken from the July 2017 issue of Toxicology and Regulatory News which is sent automatically to members of bibra.

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