Alcohols, C12-13-branched

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The first two of four key guinea pig studies were maximisation tests performed to (or similar to) OECD guideline 406. Dobanol 23 was diluted in corn oil and used for induction at 0.05% intradermal and 50% occlusive epicutaneous; the challenge application was 25% occlusive epicutaneous. Safol 23 was diluted in physiological saline and used for intradermal induction at 30% and was used at 100% for occlusive epicutaneous induction; the challenge application was 100% occlusive epicutaneous. No skin reactions were seen in the test or control groups in either study (Cassidy 1978c, Sasol 1998e).

 

In a Buehler test, also performed according to OECD guideline 406, acetone was used as the vehicle for the test material (Neodol 23) with occlusive epicutaneous induction and challenge applications at concentrations of 100% and 10% respectively. No skin reactions were seen 48 hours after challenge (Vinegar, 1976).

 

A further guideline maximisation test (summarised in four separate reports), with some deviations and not to GLP, was performed using Neodol 23. It was diluted in Freund's complete adjuvant and injected at 20, 2, 0.2 or 0.02% for intradermal induction (no epicutaneous induction was included in the protocol although this is a guideline requirement); challenge application was at 5% in acetone:methanol 90:10 epicutaneous occlusive. At the three highest induction concentrations, skin reactions were seen in 3-6 of the 7 test animals per group at 24 and 48 hours; at the lowest induction concentration, there was only one mild reaction at 48 hours; no skin reactions were seen in any control group (4 animals/group). A small number of the animals showing the most severe skin reactions (1, 4 and 2 animals respectively from the 20, 2 and 0.2% groups) and 4 control animals were re-challenged in a similar manner to the challenge application. There were positive skin reactions in 6/7 test and 0/4 control animals (Ritz, 1980a,b,c,d).

 

The Category hypothesis is that the long chain linear aliphatic alcohol family has at its centre an homologous series of increasing carbon chain length, which is associated with a consistency and predictability in the property data across the group, for the physicochemical, environmental and toxicological property data sets. In view of the structural and chemical similarities, it is considered that the results from a number of reliable skin sensitisation studies on single- or multiple-constituent alcohols with appropriate chain lengths can be read across to Alcohols C12 -13 branched.

 

No sensitisation was seen in guinea pig maximisation tests with Dodecanol (Iihama 1997a), Alcohols C12-15 branched and linear (Clark & Coombs 1978), Tetradecanol (Iihama 1997b), Alcohols C14-15 branched and linear (Biolab 1984c, Cassidy 1978d), Hexadecanol (Driscoll 1996a) or Alcohols C16-17 branched and linear (Kern 1998). There were no sensitisation reactions in a human repeated insult patch test with Alcohols C16-17 branched and linear (Pagnoni 2003).

 

A weak sensitisation reaction was seen in a modified Draize test in guinea pigs treated with Decanol (Sharp, 1978) and positive results were recorded in mouse local lymph node assays performed with Alcohols C14-15 branched and linear and with Alcohols C16 -17 branched and linear, although this study may have been confounded by skin irritation (House 2000).

In summary, negative results were reported in two of three guinea pig maximisation tests with this multi-constituent alcohol and also in a Buehler test; there were some inadequacies in the protocol used for the study that gave positive results. Negative results were obtained in similar tests with other related alcohols and a human repeated insult patch test on a related material was also negative. The weight of evidence therefore suggests that Alcohols C12 -13-branched is not sensitising.

In some cases the CAS and chemical identity stated refer to SDA nomenclature for this substance. In REACH substance identification it is necessary to be more specific as to the chain lengths present. Full details may be found in the CSR.

Migrated from Short description of key information:
In three reliable studies, Alcohols C12-13 branched and linear was not a skin sensitiser in two guinea pig maximisation tests (Cassidy 1978c, Sasol 1998e) or in a Buehler test (Vinegar 1976). A third maximisation test gave a positive result for skin sensitisation (Ritz 1980). A number of similar studies with related alcohols were negative (Biolab 1984c, Cassidy 1978d, Clark & Coombs 1978, Driscoll 1996a, Iihama 1997a, Iihama 1997b, Kern 1998) and no sensitisation was seen in a human repeated insult patch test with Alcohols C16-17 branched and linear (Pagnoni 2003). A mouse local lymph node assay with Alcohols C14-15 branched and linear and with Alcohols C16-17 branched and linear was positive, although signs of skin irritation were seen at the higher concentrations tested (House 2000).

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The test material contains no structural groups suggestive of respiratory sensitisation and, together with the lack of skin sensitising potential, it is unlikely to be a respiratory sensitiser.

Migrated from Short description of key information:
no data

Justification for classification or non-classification

Based on the available data, Alcohols C12-13-branched and linear would not be classified as a skin or respiratory sensitiser under Regulation (EC) No. 1272/2008 (CLP) or Directive 67/548/EEC (DSD). Tests on similar substances included in this category are also supportive of these results, which do not warrant classification for sensitisation under DSD or GHS criteria.