Cyanide fire smoke

It is well known that hydrogen cyanide can be liberated during combustion of nitrogen containing polymers such as wool, silk, polyacrylonitrile, or nylons (1, 2). Several investigators have reported cyanide levels in smoke from a variety of fires (3, 4, 5). The levels reported are much below the lethal levels. Thus the role of cyanide in fire deaths would seem to be quite low. However, as early as 1966 the occurence of cyanide in the blood (above normal values) of fire victims was reported (6). Since then many investigators have reported elevated cyanide levels in fire victims (7-13). However, it has been difficult to arrive at a cyanide blood level which can be considered lethal in humans. In this report the results of cyanide analysis in blood of fire victims are reported as well as the possibility that cyanide may, in some cases, be more important than carbon monoxide as the principal toxicant in fire smoke. 

Combustion of synthetic products that contain carbon and nitrogen, such as plastics and synthetic fibers, releases cyanide. Cigarette smoke contains cyanide the nonsmoker averages 0.06 pg/mL of cyanide in blood, whereas the smoker has 0.17 pg/ mL.9 The effects of cyanide and of carbon monoxide, also formed in fires, are additive because they... 

The symptoms of cyanide poisoning are well known from industrial exposure or exposure to cyanide in smoke from residential or industrial fires. Early signs and symptoms of acute cyanide poisoning include attempts of the... 

Alternative methods of treating cyanide intoxication are used in other countries. For example, the antidote used primarily in France is hydroxocobalamin (a form of vitamin B12), which combines with cyanide to form the harmless vitamin Bi2a cyanocobalamin (Baskin and Brewer, 1997 Rotenberg, 2003a). In France, this medication is used for children at a dose of 70 mg/kg. A study of 41 French children with fire smoke inhalation showed a prehospital mortality rate of 4% for those given hydroxocobalamin and not found in cardiac arrest (Geller et al., 2006). The authors of the study noted that for those children found in cardiac arrest by paramedics, administration of hydroxocobalmin did not prevent mortality. 

The use of fire retardants in polymers has become more complicated with the realisation that more deaths are probably caused by smoke and toxic combustion products than by fire itself. The suppression of a fire by the use of fire retardants may well result in smouldering and the production of smoke, rather than complete combustion with little smoke evolution. Furthermore, whilst complete combustion of organic materials leads to the formation of simple molecules such as CO2, H2O, N2, SO2 and hydrogen halides, incomplete combustion leads to the production of more complex and noxious materials as well as the simple structured but highly poisonous hydrogen cyanide and carbon monoxide. 

Samples of smoke during fires have indicated that hydrogen cyanide is not of concern in fire deaths because the levels found were much below lethal levels. 

A number of compounds act in synergy with cyanide to produce toxic effects. In smoke, hydrogen cyanide may interact with other toxicants (Birky and Clarke 1981). High blood cyanide levels were found in fire victims however, the carboxyhemoglobin levels were also high. Thus, it is difficult to assess the... 

Hydrogen cyanide has recently been recognized in significant concentrations in some fires, as a combustion product of wool, silk, and many synthetic polymers it may play a role in toxicity and deaths ftom smoke inhalation." ... 

A simple grenade which will generate either cyanide or arsenical smoke can easily be made from common materials. This device is very effective in enclosed j spaces, but poses a serious fire risk, as it operates at high temperatures. Depending on the planned use, this may not be a problem. 

Cyanide and thiocyanate are normal constituents of blood (77). Sources of cyanide include some foods, for example, cyanogenic glycosides in bitter almonds, fruit seeds, and a number of plants, cigarette smoke, and smoke from fires. The blood concentration of cyanide in healthy subjects was... 

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