Sodium alkyl sulphate

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

There are no data for skin sensitisation with C12-13AS Na (CAS 1231880-35-5) available. Therefore, a read-across to a structurally related alkyl sulfate (AS), i.e. C12-13AS Na (CAS 91783-23-2) was performed. 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.

20 Hartley guinea pigs were induced intradermal and epicutaneous with C12-13AS Na (CAS 91783-23-2, analytical purity 26.8%) in a guinea pig maximisation test performed similar to OECD Guideline 406 (Milone, 1984). Animals were treated with 25% test item in water and FCA for intradermal induction, respectively. Epicutaneous induction and challenge was performed with 12.5% test item. The concentrations based on a preliminary range-finding test. 48 h after challenge with 3.35% C12-13AS Na (based on a.s.) 2/20 animals were scored positive. 0/20 were scored positive 72 h after challenge. The negative control resulted in 2/10 and 0/10 animals with positive reactions upon challenge with 3.35% C12-13AS Na (based on a.s.). Thus the test substance was not sensitising.

 

Results of the above mentioned study show that C12-13AS Na is not a skin sensitiser. In addition 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 occurred 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 (GPMT - OECD 406): not sensitising

Justification for selection of skin sensitisation endpoint:
Reliable OECD guideline study was chosen.

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.