2-(isopropylthio)-3-(2,2,2-trifluoroethoxy)pyridine

Endpoint summary

Additional information

For the genetic toxicity two studies are available. One chromosome aberration study and one Ames test.

The in vitro chromosome aberration with ITTFEP (purity 82.3%) in Chinese Hamster V79 cells was determined in a GLP compliant test according to OECD 473, EU Method B.10 and OPPTS 870.5375. Since the study from Czich (2001) was performed under GLP and according the guideline and based on the good documentation the study was awarded with Klimisch 1. Cytotoxicity was observed after treatment with 93.8 µg/mL and above in the absence and presence with S9 mix. The positive controls showed distinct increases in cells with structural chromosome aberrations.

In conclusion it can be stated that under the experimental conditions reported, the test item did not induce structural chromosome aberrations in V79 cells.

The study from Sokolowski (2001) was performed to investigate the potential of ITTFEP (purity 82.3 %) to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100, and TA 102, and the Escherichia coli strain WP2 uvrA. The assay was performed under GLP following OECD 471 and EU method B.13/14 and based on the good documentation the study was awarded with Klimisch 1. The assay was performed with and without liver microsomal activation (S9 mix). Each concentration, including the controls, was tested in triplicate. The test item was tested at following concentrations: 33, 100, 333, 1000, 2500, and 5000 µg/plate (for TA 1537 3,10, 33, 100, 333 and 1000 µg/plate in experiment II). In both experiments, toxic effects, evident as the number of revertants, were not observed at higher concentrations with and without metabolic activation , except for TA 1537. The plates incubated with the test item showed normal background growth up to the 5000 µg/plate (1000 µg/plate for TA 1537) with and without metabolic activation in both independent experiments. No precipitation of the of the test item occurred up to the highest investigated dose. No substantial increase in revertant colony numbers of any of the six strains was observed following treatment with the test item at any dose level, neither in the presence nor absence of metabolic activation. There was no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance. Appropriate reference substances were used as positive controls and showed a distinct increase of induced revertant colonies. In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions described, the test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used. Therefore the test item is considered to be non-mutangenic in this Salmonella typhimurium and Escherichia coli reverse mutation assay. The obtained results are considered as relevant for the risk assessment.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

In conclusion it can be stated that under the experimental conditions reported, the test item did not induce structural chromosome aberrations in V79 cells nor mutation in the 6 strains used in the Ames test.