Phenol, dodecyl-, branched

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The key study for skin sensitisation (Morris, 1997) was conducted according to OECD 406 and GLP. A reliability rating of 2 according to the criteria of Klimisch, 1997 was assigned due to some background irritation being observed in the naive control animals. This study was conducted most recently and was considered to be the most reliable study.

In the supporting study for skin sensitisation there was no mention of what guideline was followed, however the methodology suggests that it was conducted similarly to OECD 406. The study was conducted in line with GLP. A reliability rating of 2 according to the criteria of Klimisch, 1997 was assigned due to some background irritation being observed in the naive control animals.

No sensitization reactions were observed in the 15 animals induced and challenged with the test material.

Migrated from Short description of key information:
The potential of the test material as 2.5% w/v in Mineral Oil to produce delayed contact hypersensitivity in guinea pigs was evaluated using an adaptation of the method of Ritz and Buehler. Following primary challenge using the test material, as a 1% w/v formulation in Mineral Oil, the incidence of grade 1 responses in the test group (2 of 19) was compared to that of the naive control group (1 of 10). The incidence and severity of these responses in the test group were essentially comparable to those produced by the naive control group suggesting that sensitization had not been induced. However one test animal responded with a grade ± at the 24 hour reading which increased to a grade 1 at the 48 hour reading. This type of response is suspect as a sensitization type response. Therefore, a rechallenge was conducted to clarify the response noted during primary challenge.
Following rechallenge using the test material, as a 1% w/v formulation in Mineral Oil, the incidence of grade 1 responses in the test group (5 of 19) was compared to that of the naive control group (2 of 10). The incidence and severity of these responses in the test group were again essentially comparable to those produced by the naive control group. The failure of the test animals to exhibit a higher incidence of responses over that of the naive control group indicates that the responses noted are due to irritation and not sensitization. Therefore, it can be concluded that sensitization had not been induced.

Justification for classification or non-classification

The key parameter chosen for skin sensitisation was greater than the criteria set out in Directive 67/548/EEC and also Regulation (EC) no 1272/2008, therefore classification for sensitisation was not considered to be necessary.