1,2-epoxycyclohexane

Endpoint summary

Additional information

Seven mammalian in vitro studies and ten in vitro bacterial studies have been provided as a weight of evidence, with additional studies providing supporting information. The general consensus of these studies is that the test material is mutagenic toxic. From information set out under endpoint 7.1 toxicokinetics, we understand that the test material is readily metabolised. The studies presented as supporting data were either performed without metabolic activation or it has not been mentioned.

The key in vivo study (National Toxicology Program, 1994) was conducted in line with sound scientific principles following a guideline similar to OECD 475, with a sufficient level of detail to assess the quality of the study. Five male Fischer 344 rats per dose were exposed to the test material via intraperitoneal injection. The test material was administered up to the level of toxicity. The study was performed to a good standard and was assigned a reliability score of 2 using the principles for assessing data quality as set out in Klimisch (1977).

Von der Hude (1990 & 1991), Godek (1980), Voogd (1981), Watabe (1980) and Frantz (1990) have all been assigned a reliability score of 2, according to Klimisch (1977).

Lippi (1981), Basler (1989), Truchi (1981), Latt (1981), Bellucci (1984), TCI Europe (2010) and Alfa Aesar (2007) have been assigned a reliability score of 4, according to Klimisch (1977).

Justification for selection of genetic toxicity endpoint

The study conducted by the National Toxicology Program was selected as the key study since it is the only available in vivo study. Moreover, the methodology employed is similar to that outlined in the standard guideline OECD 475; only minor deviations were apparent. Overall, the study was performed to sound scientific principles with a high standard of reporting; the study was assigned a reliability score of 2 and considered suitable for assessment of the test material. The study however only investigates the clastogenic potential of the substance. All other available data on the genetic toxicity of the test material are based on in vitro studies. Due to the different test systems reported in this section, it is not possible to select a key study as they are not comparable.

Short description of key information:

The genetic toxicity of the test material was determined to be negative according to an in vivo micronucleus study (National Toxicology Program, 1994) performed to a similar procedure set out in OECD guideline 475. The in vivo study demonstrates that the substance is not clastogenic however, several in vitro studies were available investigating the mutagenic potential, from the available information the overall weight of evidence suggests that the substance is mutagenic.

Endpoint Conclusion: Adverse effect observed (positive)

Justification for classification or non-classification

The test material should be classified as H341: Suspected of causing genetic defects under Regulation 1272/2008 based on the in vitro mutagenicity data.