Olfactory transduction mechanisms are best studied when specific blocking agents are available with which to modify cellular responses to odorant stimulation. This study is an electrophysiological investigation of functional group-specific olfactory acceptor mechanisms using ethylbromo acetate (EtBrAc), a World War I war gas which inhibits olfactory responses to odorant stimulation. The major findings of this investigation show that (1) vaporous EtBrAc is found to be a quick and effective inhibitor of electroolfactogram (EOG) responses to odorant stimulation, (2) isoamyl acetate is shown to protect EOG responses to a wide variety of odorants, inclusive of itself, from the inhibition effect of EtBrAc treatment, and (3) amine acceptor sites exist which are resistant to the inhibitory effects fo EtBrAc treatment.