Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

A sensitization test in albino guinea pigs was performed on the substance under registration (CAS 13863-31-5) to determine the contact allergenic potency of the test compound in albino guinea pigs. The optimization test was used, an intracutaneous sensitization procedure similar to the method recommended in the "Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics" (1959), the US Association of Food and Drug Officials (AFDO).

Under the experimental conditions employed, significant differences (P ≤ 0.05) between the test group and the vehicle treated controls were found. A skin sensitizing potential for test substance cannot be excluded, but the purity of the substance is unknown, therefore no reliable conclusion can be drawn from this experiment (Ciba-Geigy Ltd., 1975).

A further test was reported; it was performed according to OECD guideline 406 (Maximisation test on Guinea Pig) on the analogous dihydroxyethylamino derivative CAS 4193-55-9 belonging to the Stilbene Fluorescent Whitening Agents category. The liver metabolisation modelling, performed using the OECD Toolbox, indicates that the two substances (CAS 13863-31-5 and CAS 4193-55-9) share the common first pass metabolite monohydroxyethylamino.

Ten animals (5 males, 5 females) were used as control group and twenty animals (10 males, 10 females) were used as test group. Prior to the first reading of the reactions, the skin was washed-off with the vehicle petrolatum oil to clean the application site from staining produced by the test article, so that the reactions (erythema) were clearly visible at that time. The highest non-irritating concentration used for first and second challenge was 10 %. First Challenge - Erythema was observed in five out of twenty animals (25 %) at the 24-hours reading and three out of twenty animals (15 %) at the 48-hours reading when treated with a test article concentration of 10 %. Second Challenge - No positive findings were observed after the second challenge application in any animal. Therefore, according to the CLP Regulation (EC 1272/2008), the substance can be considered as non sensitising (RCC, Research & Consulting Company AG., 1989).

Within the whole category, nine over fourteen registered substances covering at least one member per group (see data matrix in the Category Justification Report attached to the section 13 of the dossier) were tested and none of the existing tests arisen any concern for skin sensitisation.

All substances of the category were modelled using the OECD Toolbox and the provisional results about sensitisation and protein binding were calculated for all members. No alerts were reported for any substance. The same was performed for CAS 13863-31-5, and a common behaviour regarding this end point within the category was observed. Based on all those considerations, the available study on the analogous substance can be considered as representative for the substance under registration, which can then be considered not sensitizing, too.

Skin adsorption was evaluated and calculated for all members of the category (see Category Justification Report, Section 13 of the dossier).

As it can be noted, the influence of the variability in functional group is very low, more related to the variability in the polarity of the substance than on potential reactivity that can arise a concern. From a metabolic point of view, an estimation with OECD Toolbox of the dermal metabolism was performed in order to verify if breakdown products could be formed. Skin adsorption is considered the condition for sensitisation to express, therefore no concern for sensitisation properties can be expected for all members of the category.

Migrated from Short description of key information:
Not skin sensitising.

Justification for selection of skin sensitisation endpoint:
Study conducted according to internationally accepted testing guidelines on an analogous substance.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

According to CLP Regulation (EC 1272/2008), 3.4 Respiratory or skin sensitisation section, skin sensitizer means a substance that will lead to an allergic response following skin contact.

The criteria to classify a substance as skin sensitizer, on the basis of results from the Guinea pig Maximization test, are reported into the second adaptation to technical progress*. A substance in considered a skin sensitizer when:

- an adjuvant type test method for skin sensitisation is used and a response of at least 30 % of the animals is considered as positive;

- for a non-adjuvant Guinea pig test method a response of at least 15 % of the animals is considered positive;

- a stimulation index of three or more is considered a positive response in the local lymph node assay.

Therefore, in the case of the Guinea pig maximisation test a substance is classify as sensitising if the results indicate that a number of animals ≥ 30 % to < 60 % responding at concentrations > 0.1 % to ≤ 1 % of intradermal induction dose or a number of animals ≥ 30 % responding at > 1 % intradermal induction dose.

Less than the 30 % of animals showed a reaction, therefore the substance can be considered as non sensitising.

In conclusion, the available experimental data are adequate for classification and labelling and the test substance is not classified as skin sensitizing according to CLP Regulation (EC 1272/2008).

*Commission Regulation (EU) No 286/2011 of 10 March 2011, amending, for the purposes of its adaptation to technical and scientific progress, Regulation (EC) No 1272/2008 of the European Parliament and of the Council on classification, labelling and packaging of substances and mixtures