(1,1,3,3-tetramethyldisiloxane-1,3-diyl)dipropane-1,3-diyl dimethacrylate

Endpoint summary

Description of key information

In the key in vivo skin sensitisation study, conducted according to an appropriate OECD test guideline and in compliance with GLP, the test material (1,1,3,3-tetramethyldisiloxane-1,3-diyl)dipropane-1,3-diyl dimethacrylate was concluded to be not sensitising to skin (Eurofins, 2017).

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The key skin sensitisation study, conducted according to OECD TG 406, and in compliance with GLP, reports the test substance, (1,1,3,3-tetramethyldisiloxane-1,3-diyl)dipropane -1,3-diyl dimethacrylate, to be not sensitising to guinea pig skin (Eurofins, 2017).

 

At induction, 3 epicutaneous occlusive applications of 100% test material were performed to the flanks of 20 test guinea pigs. The same procedure was repeated 3 times for 3 consecutive weeks. The dressing patch was held in contact with the skin for 6 hours. Dermal reactions were examined after each application.

 

At challenge (two weeks after last topical induction application), 0.5 mL of 25 % test material in acetone were applied topically to the right flank of each test animal and kept in contact with the skin for 6 hours under occlusive dressing. Dermal reactions were evaluated at 24 and 48 hours after removal of the test material. Changes in body weight were recorded prior to administration and at the end of the observation period. All animals were observed for signs of toxicity at least once daily during the test period.

There was no evidence of sensitisation as the percentage of sensitised animals was 5%. All animals of both groups survived throughout the test period. No signs of toxicity were recorded. The body weight development of all animals was within the range of variation for this strain.

A Local Lymph Node Assay draft study report is also available for the structural analogous substance, 3-(trimethoxysilyl)propyl methacrylate (CAS 2530-85-0). The study was conducted according to an appropriate OECD Test Guideline and in compliance with GLP.

Three experimental groups of five female CBA/J mice were treated with test item concentrations of 2, 5 or 10% w/w on three consecutive days, by open application on the ears. Five vehicle control animals were similarly treated, but with the vehicle alone (Acetone/Olive oil (4:1 v/v)).  Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after five hours the draining (auricular) lymph nodes were excised and pooled for each animal.

No irritation was observed in any of the animals.

The mean body weight gain shown by the animals over the study period was considered to be normal.

The majority of the auricular lymph nodes were considered normal in size, except for one node of one animal treated at a 2% test item concentration.  No macroscopic abnormalities of the surrounding area were noted for any of the animals.

The SI values calculated for the test item concentrations 2, 5 and 10% were 0.9, 1.2 and 0.9, respectively. Since there was no indication that the test item elicits a SI≥3 when tested up to 10%, 3-(trimethoxysilyl)propyl methacrylate (CAS 2530-85-0) was not considered to be a skin sensitizer. 

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the available data for (1,1,3,3-tetramethyldisiloxane-1,3-diyl)dipropane -1,3-diyl dimethacrylate, no classification is required for skin sensitisation according to Regulation (EC) No. 1272/2008.