Dibutyl terephthalate

Endpoint summary

Additional information

The mutagenic/genotoxic potential of dibutyl terephthalate has been characterized in a series of well conducted bacterial and mammalian in vitro mutagenicity tests. In a bacterial reverse mutation assay conducted according to OECD Guideline 471, there was no increase in mutation frequency in any strain of Salmonella typhimurium or Escherichia coli at concentrations up to 5000 μg/plate in the presence or absence of metabolic activation. The study was run using both the plate incorporation and pre-incubation methods. In an in vitro chromosome aberration assay conducted according to OECD Guideline 473, there was no evidence of an increase in the number of CHO cells with chromosomal aberrations or polyploidy in the presence or absence of metabolic activation, even at dose levels that caused precipitation of the test material and clear cytotoxicity. In an in vitro cell mutation assay using mouse lymphoma L5178Y cells, and conducted according to OECD Guideline 476, there was no increase in mutation frequency at the thymidine kinase locus at concentrations up to 350 μg/mL in the absence of metabolic activation or up to 700.0 μg/mL in the presence of activation. Both of these dose levels caused clear cytotoxicity. For all studies, vehicle, negative and positive controls induced the appropriate responses.

Short description of key information:
Guideline bacterial and mammalian in vitro mutagenicity studies indicate a low concern for mutagenicity.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Although no in vitro or in vivo germ cell mutagenicity/genotoxicity studies were available for review, the total weight-of-the-evidence available indicates that dibutyl terephthalate is not expected to induce heritable mutations in the germ cells of humans and is not classified for “Mutagenicity/genotoxicity” according to GHS.