A chemist, Karen Wetterhahn died after a cutaneous exposure to dimethylmercury despite wearing latex gloves. Lately, it was found that this compound permeates the latex almost immediately. This accident could have been avoided if dimethylmercury was no more used as standard in 199Hg-NMR. A safe alternative procedure allows to determine the chemical shift by means of an indirect standard, usually in proton NMR, and of the ratio of frequencies between both standards. This accident should encourage the sientific community dealing with mercuric compounds to assess their current laboratory procedures.