Reaction mass of 1,2-Benzenedicarboxylic acid, 4-sulfo-, trisodium salt, 1,2-Benzenedicarboxylic acid, 3-sulfo-, sodium salt (1:3), Sodium sulphate

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In a GLP compliant study according to OECD guideline 442B the possible skin sensitization potential of Produkt SPS was studied (Bioassay, 2012). Three groups each of five female mice were treated once daily with the test item at concentrations of 0, 2.5, 5, and 10% (w/w) in N,N- dimethylformamide by topical application to the dorsum of each ear for three consecutive days. The appropriateness of the used concentrations was previously assessed by a pre-experiment. A positive control group of five mice was treated with 25 % (w/w) α-hexyl cinnamaldehyde dissolved in N,N- dimethylformamide. Four days after the first topical application the mice were intraperitoneally injected with BrdU. Approximately 24 hours after intraperitoneally injection, the mice were sacrificed and 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 lymph nodes pooled per animal. An aliquot of each cell suspension was used for determination of lymph node cell count. The proliferative capacity of pooled lymph node cells was determined by the incorporation of BrdU measured in a photometer.

All treated animals survived the scheduled study period and no signs of systemic toxicity or local skin irritation were observed, with exception of the mean and high dose group, in which all animals showed scaling, incrustation and test item residues on day 2 and 5, only. A statistically significant or biologically relevant increase in ear weights was not observed in any treated group in comparison to the vehicle control group. Furthermore, the cut-off-value for a positive response regarding the ear weight index of 1.25 was not exceeded in any dose group. A test item is regarded as a sensitizer in the LLNA if the exposure to one or more test concentration resulted in 1.6-fold or greater increase in incorporation of BrdU compared with concurrent control, as indicated by the Stimulation Index (S.I.). The estimated concentration of test item required to produce a S.I. of 1.6 is referred to as the EC1.6 value.

In this study S.I. of 0.9, 0.5 and 1.1 were determined with the test item at concentrations of 2.5, 5 and 10 % (w/w) in N,N- dimethylformamide. An unusual dose response was observed. An EC1.6 value could not be determined as all S.I.s obtained were below the threshold of 1.6. A statistically significant or biologically relevant increase in BrdU value and also in lymph node weight and cell count was not observed in any of the tested dose groups in comparison to the vehicle control group. Furthermore, the cutoff-value for a positive response regarding the lymph node cell count index of 1.55 reported for BALB/c mice was not exceeded in any of the tested dose groups. The test item Produkt SPS was thus not a skin sensitiser under the test conditions of this study.

Migrated from Short description of key information:
LLNA (OECD 442B): not sensitizing (Bioassay, 2012)

Justification for classification or non-classification

Based on the available data, no classification and labeling is required (according to Directive 67/548/EEC and according to CLP) for skin sensitization.