Registration Dossier

Administrative data

Description of key information

Based on the weight of evidence approach between the three available studies, the regitered substance was classified as Category 1A strong sensitizer H317: "May cause an allergic skin reaction"

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)
Additional information:

Three studies were available for assessment : One in vivo LLNA and two QSARs

- 25 μl of negative control (DMSO, the vehicle), 0.25, 0.5, 1 and 2% of Lehmann-Blau in DMSO w/v was applied to the surface of the ear of five female CBA/Ca mice per group for three consecutive days. As the positive control, p-phenylenediamine (PPD) in DMSO at the same dilutions was used in parallel. On day 5, the mice received an intravenous injection of 250 μl phosphate buffered saline containing 25 μCi of [H3] methyl thymidine. Approximately 5 hours later, the mice were killed by CO2 inhalation and the draining auricular lymph nodes removed and weighed. After preparing a single cell suspension for each mouse, cells were precipitated and the radioactivity determined. The mean dpm per treated group was determined and the stimulation index (SI) – the test item compared to the concurrent vehicle control – calculated.

No concentration dependent increase in the mean SI values (1.29, 1.03, 1.12, 1.42) could be detected for the 4 consecutive concentrations of Lehmann-Blau in DMSO. The sensitivity of the test system was shown by the positive control, PPD, for which the SI were 5.47, 12.39, 19.12 and 7.07 respectively for the 4 consecutive concentrations. There was no indication of skin sensitisation by Lehmann-Blau at up to 2% in DMSO. An EC3 value could not be calculated.

- A QSAR was performed for the registered item using OECD Toolbox V4.1. This prediction was based on analogy approach with structural similar substances. Using this QSAR, the EC3 value was calculated as lower or equal to 2%. The registered item was defiend as strong sensitizer category 1A H332.

- A second QSAR was performed using VEGA v1.1.3: CAESAR 2.A.6. This perdiction was based on analogy approach with similar susbtances based on similar molecules with experimental values, accuracy of the prediction, concordance with similar molecules, atome centered fragments, model descriptors range check and global AD index. Using this QSAR, the prediction considered the registered item as sensitizer.

Justification for classification or non-classification

Based on the available studies performed in order to assess the skin sensitisation potential of the registered subtance, sensitizing effect cannot be discard. Hence, according the QSAR prediction and the LLNA, the registered substance was considered as sensitzer category 1A H317 "May cause an allergic skin reaction".