1,6-dichlorohexane

Endpoint summary

Additional information

In a mouse lymphoma forward mutation assay (2012-0184-DGM) 1,6 -dichlorohexane was tested in cultured mammalian cells (L5178Y TK +/‑) both in the presence and absence of metabolic activation by a liver post-mitochondrial fraction (S9 mix) from Aroclor 1254-induced rats according to OECD guideline No. 476 and EU B.17. The test was carried out employing two exposure times without S9 mix: 3 and 24 hours, and one exposure time with S9 mix: 3 hours; this experiment with S9 mix was carried out in two independent assays.1,6 -dichlorohexane, tested up to a cytotoxic concentration in the absence and presence of metabolic activation in two independent experiments, was negative with respect to the mutant frequency in the L5178Y TK +/- mammalian cell mutagenicity test. In addition, no change was noted in the ratio of small to large mutant colonies. Therefore, 1,6-dichlorohexane also did not exhibit clastogenic potential at the concentration-range investigated. These findings indicate that 1,6-dichlorohexane, tested up to a cytotoxic concentration in the absence and presence of metabolic activation did neither induce mutations nor have any chromosomal aberration potential.

1,6 -Dichlorohexane was tested in Ames test (2012 -0236 -DGM) according to OECD guideline No. 471 and EU method B.13/14. The test item was examined in the 5 Salmonella typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 in two independent experiments, each carried out without and with metabolic activation (a microsomal preparation derived from Aroclor 1254-induced rat liver). The first experiment was carried out as a plate incorporation test and the second as a preincubation test. Six concentrations ranging from 1.0 to 316 µg 1,6 -dichlorohexane/plate were employed in the plate incorporation test and in the preincubation test, each carried out without and with metabolic activation. In the plate incorporation test and in the preincubation test, each carried out without and with metabolic activation cytotoxicity (scarce background lawn and reduction of the number of revertants) was noted at the top concentration of 316 µg/plate in all test strains. No increase in revertant colony numbers as compared with control counts was observed for 1,6 -dichlorohexane, tested up to a cytotoxic concentration of 316 µg/plate, in any of the 5 test strains in two independent experiments without and with metabolic activation, respectively (plate incorporation and preincubation test). 1,6-Dichlorohexane tested up to a cytotoxic concentration of 316 µg/plate, caused no mutagenic effect in the Salmonella typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 neither in the plate incorporation test nor in the preincubation test each carried out without and with metabolic activation.

Furthermore, in two supporting studies (Buijs et al. 1984, Ames.BASF.1990) 1,6 -dichlorohexane was negative.

1,6-Dichlorohexane were tested in an in vitro micronucleus test (2012 -0180 -DGM) using CHO cell cultures both in the presence and absence of metabolic activation by a ratliver post-mitochondrial fraction (S9 mix) from Aroclor 1254 induced animals according to OECD guideline No. 487.

The test was carried out employing 2 exposure times without S9 mix: 4 and 20 hours, and 1 exposure time with S9 mix: 4 hours. The experiment with S9 mix was carried out twice. The harvesting time was 20 hours after the end of exposure. The study was conducted in duplicate. The concentrations employed were chosen based on the results of a cytotoxicity study. In this preliminary experiment without and with metabolic activation pronounced to complete cytotoxicity was noted starting at concentrations of 250 µg 1,6-dichlorohexane/mL in the experiments without and with metabolic activation. Hence, 250 µg 1,6-dichlorohexane/mL were employed as the top concentration for the mutagenicity tests without and with metabolic activation. In the main study cytotoxicity was noted at the top concentration of 250 µg 1,6-dichlorohexane/mL in the experiments without and with metabolic activation. 1,6-Dichlorohexane tested up to a cytotoxic concentration of 250 µg/mL in the absence and in the presence of metabolic activation employing two exposure times (without S9) and one exposure time (with S9) revealed no indications of mutagenic properties in the in vitro micronucleus test.

 

Short description of key information:
Genetic toxicity in vitro, Gene mutation: (Ames test, mouse lyphoma forward mutation assay, Micronucleus test):
- 2012-0184-DGM: mouse lymphoma cells L5178Y TK with and without metabolic activation; negative for all tested concentrations
- 2012-0236-DGM: Salmonella typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537, negative for all tested strains either with or without activation
- Buijs et al., 1984: Salmonella typhimurium strains TA 1530, TA 1535 and TA 100, negative for all tested strains without activation
- Ames.BASF.1990: Salmonella typhimurium strains TA98, TA 1537, TA 1535 and TA 100, negative for all tested strains either with or without activation
- 2012-0180-DGM: micronucleus test in cultured CHO cells, negative

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on the results, the substance was not classified according to Regulation (EC) No 1272/2008 and Directive 67/548/EEC (DSD).

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