RECOGNIZE the Toxicity — In Fire Smoke, Hydrogen Cyanide Can Be Up to 35 Times More Toxic Than Carbon Monoxide1
Between 1999 and 2008, an average of 3,625 Americans lost their lives and another 18,765 were injured annually as the result of fire.2
Although carbon monoxide (CO) is the usual focus, inhalation of fire smoke is one of the most common of all potential causes of cyanide (CN) poisoning.4,5
- 60% to 80% of US fire-related deaths are attributed to smoke inhalation8
- The focus on CO at a fire scene may cause healthcare professionals to overlook CN in fire smoke9
- The most likely cyanide poisoning sources are CN-containing materials exposed to fire4
- Cyanide is commonly found in the smoke of closed-spaced fires4
- The potential for CN toxicity as a component of smoke inhalation in today’s closed-space fires is due to the increased use of CN-containing synthetic materials used in the construction of many buildings3,4
- Hydrogen CN is also generated when natural substances, such as wool and cotton, burn3,4,8
- CN formation may be increased due to high temperature and low oxygen in closed-space fires7
- In a meta-analysis of major fire emergencies over a 19-year period, CN was found at toxic-to-lethal levels in the blood of approximately 33% to 87% of fatalities4,5
- Researchers have emphasized the need to recognize the contribution of both CO and CN in smoke inhalation injury and death3,6,7
- Even sublethal concentrations of CN and CO may indirectly cause injury or death by incapacitating a victim and inhibiting escape10,11
- In an animal model it has been shown that CN at sublethal levels combined with a low lethal concentration of CO can act synergistically to increase morbidity and mortality6
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