Sodium etasulfate

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 of C8iso AS Na (CAS 126-92-1) available. However several studies regarding skin sensitisation with other alkyl sulfates are available. Therefore, a read-across to structurally related AS, i.e. C8AS Na (CAS 142-31-4) for the endpoint skin sensitisation 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.

The key study assessed the skin sensitizing potential of C8AS Na (CAS 142-31-4, analytical purity 32%) in a Local Lymph Node Assay similar to OECD Guideline 429 (P&G, 1992). In this study 12.5 µL of a 10, 50 and 100% aqueous solution of the test substance were topically applied on 4 consecutive days to 5 female CBA mice per dose group. 21 h after the last treatment all animals received injections with radiolabelled thymidine. Animals were sacrificed 5 h thereafter and auricular lymph nodes were removed. Single cell suspensions were prepared, washed and precipitated. The total radio counts in these precipitates were subsequently quantified by liquid scintillation spectrometry. The stimulation index in the carrier control was 1. The stimulation indices for the naïve control and animals tretated with 10, 50 and 100% of the test substance were 2.4, 1.25, 2.7 and 3.1, respectively. The treatment had no significant effect on thymidine incorporation and thus the test substance showed not sensitising potential.

 

The result of the above mentioned study shows that C8AS Na (CAS 142-31-4) is not a skin sensitiser. Another alkyl sulfate, i.e. sodium lauryl sulphate (C12AS Na) is recommended as an agent to induce local irritation in a 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.

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

Justification for selection of skin sensitisation endpoint:
Reliable study conducted similar to OECD guideline 429.

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.