diethylmethoxyborane

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Additional information:

The guinea pig maximization test was performed according to OECD guideline 406 to analyze the sensitizing potential of DEMB. 10 animals were intradermally injected with a 5% solution and epidermally exposed to a 20% solution. Five control animals were similarly treated, but with vehicle only. Two weeks after epidermal applicatian all animals were challenged with a 10% and 5% test substance concentration and the vehicle. A second challenge was performed one week later with test substance concentrations of 5% and 2%. In the first challenge phase, skin reactions varying between grades 1 and 2 were observed in more than 40% of the animals 48 hours after challenge in response to 10 and 5% of DEMB. One single reaction (grade 1) was observed in a control animal. In the second challenge phase, skin reactions of grade 1 were observed in 4/9 (5% solution) and 2/9 (2% solution) animals after 24 hours and less than 5% after 48 hours in response to 5% and 2% of DEMB. In the re-challenge, again, comparable skin reactions were observed but the frequency and persistence of the responses, to the 5% concentration in particular, had decreased. The authors conclude that the responses were non-specific signs of irritation and not indicative of sensitisation. lt is therefore concluded that no hypersensitivity to DEMB had been induced.

But according to Annex VI of the EU Regulation (EC) N0. 1272/2008 (CLP) and Annex I of the EU directive 67/548/EEC, DEMB is

classified as sensitizing to the skin Cat 1 and R43, respectively.