Benzene, C20-24 (even numbered) sec-alkyl derivs.

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Additional information:

Benzene, C16-24 alkyl derivatives are also known as High Molecular Weight Linear Alkylbenzenes (HiMo LAB).  The substance is a UVCB. Because of their high molecular weight, they are very similar in composition and properties to the heavy alkylate bottoms (HABs), which are the higher boiling point residual co-products in the linear alkylbenzene (LAB) manufacturing process. Based on these structural and functional similarities, data on LAB (CAS no: 67774-74-7), LAB Alkylate Bottoms (CAS no: 85117-41-5), and HAB (CAS no: 84961-70-6) are suitable as supporting studies in case where specific data on the HiMo LAB is lacking.

To assess the skin sensitisation profile of the substance, structral analogue approach was used from Benzene, C10-13-alkyl derivs. (LAB, CAS No: 67774-74-7) and Benzene, mono-C10-13-alkyl derivatives, distillation residues (HAB, CAS No: 84961-70-6).

The study examined the potential of LAB to cause sensitization to skin according to OECD guideline 406. Groups of 20 female guinea pigs were exposed by injection to 20 and 40% test substance. One week later, they were exposed dermally to a solution of 50% test substance. The first challenge was 14 days later, and the animals were exposed to 20% test substance dermally. One week later, a second challenge was done, in which the animals were exposed to 5 and 10% test substance dermally. Animals were scored for skin irritation at 24, 48, and 72 hrs after the last challenge. The 48 hr reading was used to determine sensitization. No signs of dermal irritation were seen at this reading. The test substance in not sensitizing to skin.

The study examined the potential of HAB to cause sensitization to skin according to OECD guideline 406. A group of 10 female guinea pigs were exposed to a concentration of 50% of test substance. 10 female guinea pigs were used as controls. The induction phase consisted of two intradermal injections followed by dermal application. 14 days later, the animals were challenged by dermal application. No signs of irritation were seen in any animals during the challenge phase. The test substance is not sensitising to skin.

Based on the data from supporting analogues, HiMo LAB is considered not sensitising to skin.

Migrated from Short description of key information:

No study on skin sensitisation is available with the substance. Data from LAB (CAS no: 67774-74-7), HAB (CAS no: 84961-70-6) were used to assess the skin sensitisation potential of the substance.  The guinea-pig maximization tests were performed to the substances. Based on the woe approach from supporting analogues, the substance is considered not sensitising to skin.