I would like to know if anyone has had any specific safety-related problems with Grignard reagents. I have taught the year-long introductory Organic Chemistry sequence for about 15 years and have never had a student get any Grignard Reagent on their skin, but I've always questioned how safe it really is to have students work with these compounds (specifically PhMgBr). I have never allowed my students to work with n-butyllithium (we don't even have any in our stockroom), so it seems an odd contradiction that I have much less reluctance to have them work with Grignard reagents.
The dangers of organolithium reagents, particularly t-BuLi and -- to a lesser extent -- n-BuLi are well documented. It seems to me that the danger of these reagents largely arises from the flammability of the solvent (hexane) in which the compounds are dissolved as opposed to their extreme reactivity as bases. The organolithium reagent as it reacts with moisture provides the energy needed to ignite the solvent. Since Grignard reagents are themselves extremely basic and dissolved in highly-flammable ethers, it would seem that the dangers of physical contact with a Grignard reagent would be equal to if not greater than those of using an organolithium reagent. Just out of curiosity, has anyone actually had experience with any accidents and/or injuries involving Grignard reagents?