Sensory irritation of methylisocyanate vapor

Abstract The respiratory-depression (RD) profile in mice exposed to methylisocyanate (MIC) vapor is reported. The RD50 value calculated from this profile was 2.9 (2.7-3.2) ppm. Concentrations of MIC that have been reported to be unbearable in humans were of approximately the same magnitude as RD50 concentrations in mice for brief exposures.