In a routine safety evaluation of chemicals included in household products, we found a mixture of azo dyes (CMBA, main component: N-[5-[(2-cyanoethyl) ethylamino]-4-methoxy-2-[(5-nitro-2,1-benzisothiazol -3-yl)azo]-phenyl]acetamide) that precipitated in the culture medium in a characteristic fibre form (around 2-33 ím in length) similar to that of asbestos. The authors compared CMBA with an asbestos, chrysotile B, in a cytotoxicity, chromosome aberration (CA), and micronucleus (MN) test in a Chinese hamster lung cell line (CHL). In the cytotoxicity test, the 50% growth inhibition concentration was 11.0 íg/mL for CMBA and 0.398 íg/mL for chrysotile B asbestos. CMBA and chrysotile B both induced polyploidy in the CA test and equal-sized binucleated and polynuclear cells in the MN test. CMBA differs from chrysotile B chem. The former is an organic chemical and the latter is a mineral. Although CMBA is soluble in methanol and can be safely disposed by burning, it should be handled carefully when manufactured in a factory.
Authors: Matsuoka Atsuko; Matsuda Yoshie; Kaniwa Masa-aki ;Full Source: Kokuritsu Iyakuhin Shokuhin Eisei Kenkyusho Hokoku 2010, 128, 65-70 (Eng) ;