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SYNTHESIS AND MUTAGENICITY OF DIRECT DYES FROM 4,4'-DIAMINO-PARA-TERPHENYL AND 4,4'-DIAMINO-PARA-QUATERPHENYL
Citation:
WANG, J., H. S. FREEMAN, AND L. D. CLAXTON. SYNTHESIS AND MUTAGENICITY OF DIRECT DYES FROM 4,4'-DIAMINO-PARA-TERPHENYL AND 4,4'-DIAMINO-PARA-QUATERPHENYL. Coloration Technology. Blackwell Publishing, Malden, MA, 123(1):39-45, (2007).
Impact/Purpose:
This study was an effort to determine, based on toxicity, whether or not some specific benzidine analogs are potential replacements for benzidine and its genotoxic congeners.
Description:
DBPs in drinking water can be controlled by the type of treatment and by knowing and controlling major sources of DBP toxicant precursors and toxicants that "evade" treatment processes. Efforts are being directed at one category at a time. The initial precursor categories to be considered are pharmaceuticals, municipal sludge, and dyes/pigments. Because studies in Japan, Brazil, Germany, and the US have identified that dyes can contribute extreme levels of toxicants to source waters and because this is a "relatively narrow" class, dyes were the first category chosen. Initial efforts are (1) examining source and drinking waters from Brazil and the identified azo dyes and (2) making efforts to design, synthesize, and evaluate replacement dyes. Goals for the development of replacement dyes and pigments are making ones that are (1) environmental and health effects friendly and (2) retain good straining properties for commercial use. The results will also be useful to those involved in the PMN (premanufacturing notice) process and those involved in the Safe Pesticides/Safe Products (SP2) programs.
What is the impact to thefield and the Agency?
In this study, it was found that 4,4'-diamino-para-terphenyl (DATP) and 4,4'-diamino-para¬quaterphenyl (DAQP) coupled with naphthalene derivatives produced direct dyes that are potential replacements for carcinogenic benzidine dyes. The mutagenicity assay (Ames test) revealed that dyes based on DAQP were generally less mutagenic that those based on DATP. When the corresponding preincubation assay (Prival modification) was used, it was clear that using DATP in place of benzidine significantly reduced the mutagenicity of Congo Red. While the use of DAQP gave a further reduction, it did not fully remove the mutagenicity. The study aids in identifying benzidine replacements that are potentially useful to the dye industry but are less likely to cause human health effects. This structure-activity study also aids in the development of computational toxicology methods for predicting the genotoxicity of similar compounds.