1,6-dichlorohexane

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In the key study, the test item was assessed for its skin sensitising potential using the Local Lymph Node Assay (LLNA) in mice according to OECD guideline 429 and EU guideline B.42. The method used for the study employing the lymph node weight and lymph node cell count to assess proliferation has been established by an European interlaboratory validation exercise, as described in the two publications by Ehling et al. 2005a and 2005b. This method has the advantage of (i) more simplistic experimental work, (ii) less variability, (iii) better reproducibility, (iv) faster results. In addition, the acute inflammatory skin reaction is measured by ear weight determination of circular biopsies of the ears and ear thickness measurements on test day 1 and test day 4 to identify skin irritation properties of the test item. It is important to determine if a positive test result is due to the skin irritation potential of the test item or due to its sensitising properties. Stimulation indices were calculated for the lymph node cell count, lymph node weight, ear weight and ear thickness by dividing the average values per group of the test item treated animals by the vehicle treated ones. Values above 1.4 (lymphnode cell count to identify sensitisation) or 1.1 (ear weight to identify irritation) are considered positive (these values were fixed empirically during the inter-laboratory validation of this method (Ehling et al. 2005a and 2005b)). Three concentrations of 1,6-dichlorohexane(25% and 50%, diluted with acetone/olive oil (3+1 v/v)) (w/w) or the undiluted test item (100%) were tested in six female NMRI mice per group and compared to a vehicle control group. In addition, a positive control group (25% solution v/v alpha-hexyl cinnamic aldehyde in acetone/olive oil (3+1 v/v)) was employed. Treatment with 1,6-dichlorohexaneat concentrations of 25%, 50% or 100% did not reveal statistical significantly increased values for lymphnode cell count. The stimulation indices of the lymph node cell count did not exceed the threshold level of 1.4. Hence, the test item is classified as not sensitising. The threshold level for the ear weight of 1.1 was not exceeded and no increase of ear thickness was observed, i. e. no irritating properties were noted. The positive control group caused the expected increases in lymph node cell count and lymph node weight (statistically significant at p ≤ 0.01). Therefore, the study can be regarded as valid. No signs of local or systemic intolerance were recorded. The animal body weight was not affected by the treatment. 1,6-dichlorohexane at concentrations of 25% or 50% (w/w) in acetone/olive oil (3+1 v/v) or the undiluted test item did not reveal any sensitising properties in the local lymph node assay.

Migrated from Short description of key information:
The sensitizing potential of the substance was tested in an in-vivo study (LLNA). 1,6-dichlorohexane at concentrations of 25% or 50% (w/w) in acetone/olive oil (3+1 v/v) or the undiluted test item did not reveal any sensitising properties in the local lymph node assay.

Justification for selection of skin sensitisation endpoint:
One key study is available.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

The test item has no structural alert indicative for respiratory sensitisation. In addition, no human data on respiratory sensitisation have been reported. The test item is considered not to induce respiratory sensitisation.

Migrated from Short description of key information:
Considered not to induce respiratory sensitisation.

Justification for classification or non-classification

Skin sensitisation

Based on the results of an in vivo skin sensitisation test, the test item should not be classified with regard to skin sensitisation according to Directive 67/548/EEC and Regulation (EC) No 1272/2008 (GHS, CLP).

Respiratory sensitisation

Considered not to induce respiratory sensitisation.