Reaction mass of 2-(methylamino)ethanol, compound with sulphur dioxide and bis[(2-hydroxyethyl)ammonium] sulphite

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The sensitising potential of 2 -Aminoethanol (MEA), as well as di- and triethanolamine (DEA and TEA), was studied using the guinea pig maximisation test (Wahlberg and Boman, 1996). Groups of 15 animals were induced with either MEA, DEA or TEA and then challenged after three weeks with the inducing amine and the two others. Prior to the topical induction, pretreatment with 10 % Sodium dodecyl sulfate was carried out. The challenge reactions were read blindly 48 and 72 hours after application of the patches. Control groups of twelve animals were given the same treatment (FCA, vehicle, occlusion, etc.) except for the inducing amine. No statistically significant difference between actively induced animals and control animals was observed and there was no indication of cross reactivity.

One reliable animal study, according to OECD guideline 429 (Skin Sensitisation: Local Lymph Node Assay, modified according to Ehling et al., 2005) was performed for Sodium sulfite which showed that the test item had no sensitising properties at concentrations of 10, 25 and 50 % in aqua ad iniectabilia (LPT, 2010; 25738). The positive control group caused the expected increases in lymph node cell count (S.I.: 2.106) (statistically significant at p ≤ 0.01); the stimulation index for lymph node weight was 2.160 and for ear weight 1.040. In a similar study conducted according to the same protocol with Disodium disulfite at concentrations of 10, 25 or 50 % in aqua ad iniectabilia (LPT, 2010; 25740), no skin sensitising properties were noted. The positive control group caused the expected increases in lymph node cell count (S.I.: 2.427) and lymph node weight (S.I.: 2.160) (statistically significant at p ≤ 0.01). The stimulation index for ear weight was 1.033. In both studies, the stimulation indices in the test groups were below the respective threshold values.

Nevertheless it has to be mentioned that in human individuals urticaria and asthma with itching, edema, rhinitis, and nasal congestion were reported (OECD SIDS; 2004) An immunological pathogenesis of these findings are not still clear.

The skin sensitization potential of Methyethanolamine was evaluated in a guinea pig maximization procedure by the method of Magnusson and Kligman (Leung and BlaszcaK, 1998). Eighteen of the 20 animals challenged with a 5% concentration of MMEA were free of skin response, and the 2 animals had clear skin response (scores of 1) at 24 h but not at 48 h following dosing. Since the positive response was seen only in two out of twenty animals (10%) instead of 30% and more, Methyethanolamin does not possess significant skin sensitizing properties.

Migrated from Short description of key information:
The salt Bis[(2-hydroxyethyl)ammonium] sulfite is considered highly unlikely to possess skin sensitisation potential. None of the ions/salts that result from its dissociation in aqueous systems and that were tested with counterions of no toxicological significance (Na+, H+) displayed skin sensitising properties in reliable standard tests. These surrogate substances were 2-Aminoethanol, Methylethanolamin, Sodium sulfite and Disodium disulfite.
Please refer also to the read-across and weight-of-evidence statement provided in section 13.

Justification for selection of skin sensitisation endpoint:
A weight-of-evidence approach is used to assess the skin sensitisation hazard of Bis[(2-hydroxyethyl)ammonium] sulfite.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the current weight-of-evidence, Bis[(2 -hydroxyethyl)ammonium] sulfite is not subject to classification for skin sensitisation according to Directive 67/548/EEC (DSD) and Regulation (EC) No 1272/2008 (GHS/CLP).