C8-18 (even numbered) and C18 (unsaturated) sarcosinates, 2-hydroxypropylammonium salt

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

There is one study according to OECD guideline 406 available for the test item (Latour, 2016). The Guinea Pig Maximisation Test was chosen for the assessment of the sensitising properties because the test substance is a detergent, and these surfactant substances are prone to produce false-positive results in the Local Lymph Node Assay, for example.

The appropriate concentrations for intradermal and epidermal induction and epidermal challenge were determined in a dose-range finding experiment which was included in the study design. Based on the observations in this test a 0.1% test item concentration was chosen for intradermal induction, and a concentration of 2% was chosen for epidermal induction and challenge applications.

For intradermal induction the animals received 3 pairs of injections according to the combinations described in the guideline on both sides of the clipped scapular region, one injection of each pair on either side of the midline, on Day 1. On Day 8 the scapular area between the injection sites was clipped and subsequently treated with a 2% test item concentration under occlusive dressing for 48 hours. The control animals were treated in analogous fashion except that the test item was replaced with vehicle. On Day 21 one flank of all animals was clipped and treated by epidermal application of a 2% test item concentration and vehicle under occlusive conditions using two Patch Test Plasters approximately 2 cm apart. By that approach the opposite flank remained virgin for an optional re-challenge, if required. The occlusive dressings were removed after 24 hours; the treated and cleaned skin sites were assesed for challenge reactions 24 and 48 hours after removal of the dressing (i.e. 48 and 72 hours after challenge).

The minor skin reactions (Grade 1) other than scaliness observed in response to the 2% challenge concentration in 1/10 animals of the test group were considered indicative of sensitisation, based on the absence of reactions in the control animals, which represents a sensitisation rate of 10%.

According to the criteria outlined in OECD guidline 406, which regard a sensitisation rate of at least 30% in an adjuvant test as threshold for consideration of a substance as mild sensitiser, the test substance does not have to be considered as skin sensitising.

Migrated from Short description of key information:
GPMT (OECD 406): not sensitising

Justification for selection of skin sensitisation endpoint:
Only one study available for the endpoint.

Justification for classification or non-classification

Based on the available results the test item does not have to be classified for sensitisation according to the criteria of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2015) (including all amendments) and the criteria of Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments). The available data is conclusive but not sufficient for classification.