Alcohols, C16-17-branched and linear

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

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

 

The first of three key studies was performed to GLP according to OECD guideline 406 (maximisation test). The test material (Development Detergent alcohol 23731-52) was mixed with PEG 400 for intradermal induction at 5% and was used at 100% for occlusive epicutaneous induction; the challenge and re-challenge applications were 2.5% and 0.5% occlusive epicutaneous respectively. Skin reactions were seen in a high proportion of animals in both test and control groups following challenge and in a low proportion following re-challenge. Since the reactions in the test group were no more intense than the response to the test material in the negative control group, the test material was not considered to be a skin sensitiser in this study (Kern 1998).

 

The second key study was performed to GLP using a protocol equivalent to OECD guideline 429 (local lymph node assay). A dose-related increase in lymphocyte proliferation in the auricular lymph nodes was seen after application of the test material (Neodol 67) at 1, 10, 25 and 50% in acetone:olive oil 4:1, with stimulation indices of 0.8, 4.2, 8.2 and 16.2 respectively (statistically significant at the top three concentrations). Erythema was noted at the two highest concentrations, which may suggest that the proliferation was caused by irritation (however, the known sensitiser used as the positive control also induced erythema). Positive results were also recorded in this assay when performed with Alcohols C14-15 branched and linear (House 2000).

 

The third key study was a human repeated insult patch test performed to Good Clinical Practice; no guideline was available but a published protocol was followed; 103 subjects participated in the study. The induction phase involved semi-occlusive application of the test material (Neodol 67) at 0.5% in a moisturizer base for 24-72 hours on 9 occasions over 4 weeks. Following 10-21 days rest, a challenge patch, also at 0.5%, was applied to a different site for 24-48 hours and skin responses were scored 48 and 72-96 hours after patch removal. No skin sensitisation reactions were seen (Pagnoni 2003).

 

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 C16-17 branched and linear.

No sensitisation was seen in guinea pig maximisation tests with Tetradecanol (Iihama 1997b), Alcohols C12 -15 branched and linear (Biolab 1984c, Cassidy 1978d), Hexadecanol (Driscoll 1996a) or Octadecanol (Driscoll 1996b) or in a repeated application test in rabbits with 9-Octadecenol-1-ol (9Z) (Guillot 1977).

 

In view of the negative results reported in the guinea pig maximisation test with this multi-constituent alcohol and other related alcohols, a negative result in a human repeated insult patch test and possible evidence of irritation as a likely confounder in the local lymph node assay, the weight of evidence suggests that Alcohols C16-17 branched and linear is not sensitising.

Migrated from Short description of key information:
In a reliable study, using a protocol similar to OECD guideline 406, Alcohols C16-17 branched and linear was not a skin sensitiser in the guinea pig maximisation test (Kern 1998) and a number of similar studies with related alcohols were also negative (Biolab 1984c, Cassidy 1978c, Cassidy 1978d, Driscoll 1996a, Driscoll 1996b, Guillot 1977, Iihama 1997b). 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 C16-17 branched and linear (and with Alcohols C14-15 branched and linear) was positive, although signs of skin irritation seen at the higher concentrations tested may have confounded the result (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 weight of evidence suggesting a 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 C16-17 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.