With the available information, what is your overall conclusion on the mutagenic potential of 1,3-D (please explain)?

I could not locate the Lawlor refs for the Ames test, so I can't evaluate them. I'd like to get the ref for the clean state of the art mutagenicity data referred to. The Watson paper reported a low, but apparently positive response for highly purified 1,3-D. However, no raw data were included and no dose response data were included. Metabolism of 1.3-D to its epoxide apparently occurs, but is minor pathway. However, the 1,3-D-epoxide is reactive with dG (Schneider, 1998) and based on reactivity of other alkyl epoxides would be expected to react with DNA. Thus, I believe a strict answer to the above question is yes. However, based on the low yield of the epoxide and its detoxification by glutathione, I do not think it poses a mutagenic threat in vivo.

There is an error in the ref in the above comment - the paper referred to is R.E. Talcott, 1984. The Watson paper does show a clear mutagenic dose response for purified 1,3-D in the presence of metabolic activation, but this greatly reduced by glutathione.

I too do not think it poses a mutagenic threat in vivo

The question is confounded by the lack of context...mutagenic potential in vitro? in vivo? in humans? This may explain the difference in the answers in the original review. I agree that, based on the available data, it is most likely not mutagenic in vivo.