Registration Dossier

Administrative data

Description of key information

Based on the results of a local lymph node assay conducted on mice, the test substance was considered to be not skin sensitising.

Key value for chemical safety assessment

Skin sensitisation

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

Local Lymph node assay

The test item was assessed for its skin sensitising potential using the Local Lymph Node Assay (LLNA) in mice. The study was conducted in compliance with GLP and according to OECD Guideline 429. Test item concentrations of 2, 5, and 10% (w/w) in DMSO were used. The highest concentration tested was the highest concentration that could be achieved whilst avoiding systemic toxicity and excessive local skin irritation (as determined by a pre-experiment). The animals did not show any signs of systemic toxicity during the course of the study and no cases of mortality were observed. In this study Stimulation Indices (S.I.) of 0.87, 1.23, and 1.08 were determined with the test item at concentrations of 2, 5, and 10% (w/w) in DMSO, respectively. A dose response was not observed. A statistically significant and biologically relevant increase in DPM value and also in lymph node weight and cell count was not observed in any of the dose groups in comparison to the vehicle control group. Furthermore, the cut-off value of 1.55 for a positive response regarding the lymph node cell count index reported for BALB/c mice was not exceeded in any dose group. Thus, the test item was not a skin sensitiser under the test conditions of this study.

Optimization Test

In a skin sensitization study in guinea pigs (Optimization test (Maurer Th.) and Draize) 10 Pirbright White guinea pigs per sex were injected 10 times intracutaneaus, every second day (except weekends), (0.1% solution of test substance in saline 0.9%). During the second and third week of the induction period the test material was incorporated in a mixture of the normal vehicle with complete Bacto Adjuvant. Fourteen days after the last sensitizing injection, a challenge injection of 0.1 mL 0.1 % solution of test substance in saline 0.9% was administered into the skin. 24 Hours after the challenge injection reactions were recorded. Ten days after the intracutaneous challenge injection a subirritant dose of the test compound was applied epicutaneously under occlusive dressings which were left in place for 24 hours. The skin irritation was recorded according to Draize. Significant differences between the test group and the vehicle-treated controls were only seen after intradermal challenge application of the test substance, i.e. when the skin barrier was intentionally by-passed. An epidermal challenge was carried out and found to be negative, but the assessment was difficult since the compound had a reddish colour. No differences between the test and the control group was seen after epidermal challenge application. The negative results upon epidermal challenge demonstrate that, in artificially sensitizied guinea-pigs, exposure of the intact skin to the test compound does not provoke contact dermatitis. However, the study is performed quite some time ago and does not comply with the current guidelines and with guidelines which were in place from 1992 on. The method applied uses intradermal injections only for induction. Furthermore, the topical challenge was performed with a very low test concentration (0.1%) and at a rather late date after induction (10 days after the intradermal challenge and 24 days after the final induction treatment). Normal test concentrations of powders to be examined in sensitization studies by topical application are usually 10-50%.


Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Dangerous Substance Directive (67/548/EEC)

The available studies are considered reliable and suitable for classification purposes under 67/548/EEC. As a result the substance is not considered to be classified for skin sensitization under Directive 67/548/EEC.

                               

Classification, Labeling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. As a result the substance is not considered to be classified for skin sensitization under Regulation (EC) No. 1272/2008.