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Key value for chemical safety assessment

Additional information

Several in vitro and in vivo mutagenicity and genotoxicity studies were found for NG, which are listed below:

  • One in vivo dominant lethal genotoxicity test in rats;
  • Six in vivo chromosome aberration tests in rat bone marrow, rat kidney cells and rat lymphocytes, dog kidney cells, and dog lymphocytes;
  • One in vitro chromosome aberration test in Chinese hamster ovary cells;
  • One in vitro mutagenicity test in Chinese hamster ovary cells; and
  • Five in vitro AMES tests in several strains of Salmonella typhimurium.

Out of these 14 mutagenicity/genotoxicity tests, one strain (TA1535) of S. typhimurium showed susceptibility to single base pair changes (i.e., Cā†’T transitions) (Wink et al.1991). A follow-up AMES test on this strain and six others (Maragos et al.1993) suggested that NG is weakly mutagenic to this particular strain and none of the others tested. Specifically, the single base pair changes were observed in the first or second position of the hisG46 codon (CCC). Using the TA1535 strain, this same pattern of mutagenicity was observed in response to nitric oxide. Given that nitric oxide is generated when NG is metabolized, the authors postulated that it is likely nitric oxide and not NG that is responsible for the mutagenicity observed in the TA1535 strain.  

Short description of key information:

No studies were available for EGDN and as such, conclusion is based on available genotoxicity assays on NG (read-across).  EGDN is not considered to be mutagenic based on negative results in in vitro gene mutation studies in bacteria and mammalian cells and in vivo assays in mammalian cells.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

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