Hydrogen cyanide

Approximately 60 to 70% of the population can detect the bitter almond odor of hydrogen cyanide. The odor threshold for those sensitive to the odor is estimated to be 1 to 5 ppm in the air. However, even at high toxic concentrations, up to 20% of all individuals are genetically unable to smell hydrogen cyanide.

Detection in air of hydrogen cyanide of an unspecified purity or grade: 1X10-3 mg/L.

High odor threshold was 5 mg/cu m; Low odor threshold was 0.9 mg/cu m.