Mutagenicity in Salmonella of dyes used by defence personnel for the detection of liquid chemical warfare agents.

Abstract

Paper strips containing indicator dyes have been developed by defence scientists to change color upon exposure to certain agents but not to common solvents. As a preliminary step in studies on their possible genetic or carcinogenic hazard, 6 dyes used in these detection papers were tested with the Salmonella/mammalian-microsome assay. The 3 nitro arenes tested were found to be mutagenic. Two of them, Orasol Navy Blue 2RB (without metabolic activation) and Eastman Fast Blue B-GLF (with metabolic activation), induced higher yields of mutations in the frameshift revertible strains, but base substitution mutations also were found. The third nitro arene, ethyl-bis-(2,4-dinitrophenyl) acetate, induced only frameshift reversions, the greatest yields without metabolic activation. Because of weak but consistent mutagenic activation. Because of weak but consistent mutagenic effects with a fourth dye, thiodiphenyl-4,4'-diazo-bis-salicylic acid, fluctuation tests using Salmonella strain TA98 were performed, and dose-related, statistically-significant mutagenic responses were observed. Two remaining dyes, Fluorescent Brilliant Yellow R and 2,5,2',5'-tetramethyltriphenylmethane-4,4'-diazo-bis-beta-hydroxynaphthoic anilide, were not mutagenic in experiments using doses extending into the toxic range. Spot tests were performed on different paper strips containing the dyes. When the papers were eluted with dimethyl sulfoxide, responses were found to be qualitatively similar to those in the plate tests. Although microbial test results cannot be used to assess risk in man, these results indicate a potential mutagenic or carcinogenic hazard for individuals exposed to these dyes, especially the nitro aromatics.