Carbon Monoxide Headquarters
Other Nasty gases, Dr. D. Penney





Hydrogen Cyanide

Dangerous and Lethal Doses:

  • Human - Exposure to 150 ppm for 30-60 minutes endangers life. Death can occur from a few minutes exposure to 300 ppm

  • Human - Average fatal dose 50-60 mg

  • Animal - LC50 by inhalation in rats, mice, dogs - 544 ppm (5 min.); 169 ppm (30 min.); 300 ppm (3 min.)

  • Antidote - Amyl nitrite (inhalation), sodium nitrite (300 mg) and sodium thiosulfate. Nitrite converts hemoglobin to methemoglobin, which then mops up circulating free cyanide, forming cyanmethemoglobin. Thiosulfate converts cyanide to thiocyanate through the action of the enzyme rhodanase. Hyperbaric oxygen treatment is useful in connection with nitrite and thiosulfate treatment.




    ...... last changed 05/22/00


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