Sodium 2-butyloctyl sulphate

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

There is no study regarding skin sensitisation with C12AS branched Na (CAS 94200-74-5) available. Therefore this endpoint is covered by read across to structurally related alkyl sulfates (AS), i.e. C12AS Na (CAS 151-21-3). The possibility of a read-across to other alkyl sulfates in accordance with Regulation (EC) No 1907/2006 Annex XI 1.5. Grouping of substances and read-across approach was assessed. In Annex XI 1.5 it is given that a read-across approach is possible for substances, whose physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity. The AS reported within the AS category show structural similarity. The most important common structural feature of the category members is the presence of a predominantly linear aliphatic hydrocarbon chain with a polar sulfate group, neutralized with a counter ion. This structural feature confers the surfactant properties of the alkyl sulfates. The surfactant property of the members of the AS category in turn represent the predominant attribute in mediating effects on mammalian health. Therefore, the AS of the AS category have similar physico-chemical, environmental and toxicological properties, validating the read across approach within the category. The approach of grouping different AS for the evaluation of their effects on human health and the environment was also made by the OECD in the SIDS initial assessment profile [1] and by a voluntary industry programme carrying out Human and Environmental Risk Assessments (HERA [2]), further supporting the read across approach between structurally related AS.

There is one study available addressing skin sensitisation for the read-across substance C12AS Na (CAS 151-21-3).

The skin sensitizing potential of C12AS Na (CAS 151-21-3) was assessed in a local lymph node assay similar to OECD guideline 439 (Ikarashi, 1993) on 3 mice per dose and experiment. BALB/c mice were treated daily via topical application (25 µL) of 5, 10 and 25% aqueous solution of the test item on 3 consecutive days. In another experiment intradermal injections (50 µL) were performed with concentrations of 0.05, 0.5 or 5% in saline. Five days after intradermal injection, mice were challenged daily by dermal application of 25 µL of a 5% solution in vehicle (DMSO 50%) on the ears for 3 consecutive days. The day after the final exposure, changes in lymph node weight, total cell number in the draining lymph nodes and LNC proliferation for 24 h culture were assessed. The stimulation indices in the first experiment were 0.7, 1.6 and 1.1 at 5, 10 and 25%. After intradermal application of 0.05, 0.5 or 5% test item and subsequent dermal challenge with 5% test item the stimulation indices were 1.6, 1.9 and 1.5.

Results of the above mentioned study show that C12AS Na (CAS 151-21-3) is not a skin sensitiser. In addition, sodium lauryl sulphate (C12AS Na) was used within this study as known irritant to produce irritant effects. Likewise sodium lauryl sulphate is also recommended as an agent to induce local irritation in an OECD method to assess skin sensitising properties of chemicals (OECD guideline 406, Guinea Pig Maximisation Test). Therefore there is a lot of experience with sodium lauryl sulfate in sensitising studies and no evidence occured that it shows sensitising properties. Thus, skin sensitisation by members of the alkyl sulfates is generally unlikely.

 [1] SIDS initial assessment profile, (2007);
http://www.aciscience.org/docs/Alkyl_Sulfates_Final_SIAP.pdf

[2] (HERA Draft report, 2002);
http://www.heraproject.com/files/3-HH-04-%20HERA%20AS%20HH%20web%20wd.pdf

Migrated from Short description of key information:
Skin sensitisation (LLNA - OECD 429): not sensitising

Justification for selection of skin sensitisation endpoint:
Reliable study similar to OECD guideline.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The available data on skin sensitisation do not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.

No data available for respiratory sensitisation.