m,m'-[(9,10-dihydro-9,10-dioxo-1,4-anthrylene)diimino]bis[2,4,6-trimethylbenzenesulphonic] acid, compound with hexane-1,6-diamine (1:1)

Endpoint summary

Description of key information

The test item was not a skin sensitiser when tested in a GLP-compliant LLNA following OECD guideline 429.

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In order to study a possible skin sensitising potential of the test item three groups each of five female mice were treated once daily with the test item at concentrations of 2, 5, and 10% in DMSO by topical application to the dorsum of each ear for three consecutive days. The test item could be suspended in the vehicle. The appropriateness of the used concentrations was previously assessed by a pre-experiment. A control group of five mice was treated with the vehicle DMSO only. Five days after the first topical application the mice were injected intravenously into a tail vein with radio-labelled thymidine (3H-methyl thymidine). Approximately five hours after intravenous injection, the mice were sacrificed, the draining auricular lymph nodes excised, pooled per animal and immediately weighed. Furthermore, after excision of the lymph nodes, both ears of the mice were punched at the apical area using a biopsy punch and were immediately weighed pooled per animal using an analytical balance. Afterwards single cell suspensions of lymph node cells were prepared from pooled lymph nodes per animal. An aliquot of each cell suspension was used for determination of lymph node cell count. Subsequently the suspensions were washed and incubated with trichloroacetic acid overnight. The proliferative capacity of pooled lymph node cells was determined by the incorporation of 3H-methyl thymidine measured in a β-scintillation counter. The animals neither showed any signs of systemic toxicity nor mortality during the course of the study. Redness of the ear skin could not be observes due to the colour of the test item. On day 6, during preparation, slightly scaly ears were observed in all dose groups. However assessment of ear skin alterations was difficult due to the blue colour of the test item. A statistically significant increase in ear weights was observed in the high dose group in comparison to the vehicle control group (p<0.05). For BALB/c mice, a cut-off value of 1.1 for the ear weight index was reported for a positive response regarding ear skin irritation. None of the indices determined for the test item treated groups reached or exceeded this threshold. Thus, the statistically increased ear weights in the high dose group were considered to be not biologically relevant. A test item is regarded as a sensitiser in the LLNA if exposure to one or more test item concentration results in a 3-fold or greater increase in incorporation of 3HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated test item concentration required to produce a S.I. of 3 is referred to as the EC3 value. In this study Stimulation Indices (S.I.) of 0.7, 1.1, and 1.2 were determined with the test item at concentrations of 2, 5, and 10% in DMSO, respectively. The EC3 value could not be calculated, since none of the tested concentrations induced a S.I. greater than the threshold value of 3. A statistically significant or biologically relevant increase in DPM value and also in lymph node weight and -cell count was not observed in any treated group 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 reached or exceeded in any dose group. In conclusion, the test item was not a skin sensitiser under the test conditions of this study.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available