Cyanogen exposure

Appropriate PPE must be worn by members of emergency services treating casualties with suspected cyanogen exposure. Secondary contamination is unlikely. 

Effects from vapor exposure begin to appear 1-2 minutes after exposure. Pulmonary edema, caused by inhalation of cyanogen halides, does not occur until after a substantial latency period. 

Exposure to solid or liquid cyanogen halides can cause skin and eye irritation. Otherwise, casualties exposed to cyanides experience few effects at sublethal doses. Percutaneous absorption of a lethal dose may produce temporary rapid and deep breathing followed by convulsions and unconsciousness. Under these circumstances, the casualty will stop breathing within 2-4 minutes after exposure. Death will occur 4-8 minutes later. 

This section provides information regarding known health effects of cyanide exposure. Exposure to hydrogen cyanide (HCN) gas is most common by inhalation. In the discussion below, inhalation exposures are expressed as ppm hydrogen cyanide. Exposure to cyanide can also occur by inhalation of cyanogen gas, a dimer of cyanide. However, cyanogen breaks down in aqueous solution into cyanide ion (CN1) and OCN" ions (Cotton and Wilkinson 1980). The rate of the breakdown depends on pH and is... 

Respiratory Effects. Initially, respiration is stimulated, but later dyspnea occurs in patients admitted to a hospital after acute hydrogen cyanide exposure (Chen and Rose 1952 Peden et al. 1986 Potter 1950). The levels of exposure in these accidental poisonings were not provided. Nasal irritation was reported in volunteers exposed to 16 ppm cyanogen (8 ppm cyanide) for 6-8 minutes (McNemey and Schrenk 1960). No effects were reported at 8 ppm cyanogen (4 ppm cyanide). 

Asphyxia has been observed in rats exposed to 250 ppm cyanogen (125 ppm cyanide) for 7.5-120 minutes (McNemey and Schrenk 1960), asphyxia and pulmonary edema were observed in dogs exposed to concentrations ranging from 149 to 633 ppm hydrogen cyanide (143-608 ppm cyanide) for 2-10 minutes (Haymaker et al. 1952), while severe dyspnea was observed in monkeys exposed to 100 ppm hydrogen cyanide (96 ppm cyanide) for 30 minutes (Purser et al. 1984). Exposure to 63 ppm hydrogen cyanide (60 ppm cyanide) for 30 minutes resulted in a 50% decrease in respiratory rate of mice due to depression of the respiratory center (Matijak-Schaper and Alarie 1982). 

Bradycardia, arrhythmias, and T-wave abnormalities were observed in monkeys exposed to 100 ppm hydrogen cyanide (96 ppm cyanide) for 30 minutes (Purser et al. 1984). Increased cardiac-specific creatinine phosphokinase activity was measured in blood samples from rats 2 hours after 12.5 minutes of exposure to 200 ppm hydrogen cyanide (192 ppm cyanide) for 20 days at 4-day intervals (O Flaherty and Thomas 1982). However, no treatment-related changes were found in the hearts at histopathology. In addition, no cardiovascular effects were reported at necropsy in rats and monkeys exposed to 25 ppm cyanogen (50 ppm cyanide) for 6 months (Lewis et al. 1984). 

Information regarding ocular effects in animals after inhalation exposure to cyanide is limited to a report of eye irritation in rats acutely exposed (7.5-120 minutes) to 250 ppm cyanogen (500 ppm cyanide) (McNemey and Schrenk 1960). 

When the skin of rabbits was exposed to 5,000 ppm cyanide as cyanogen for 8 hours, no dermal lesions were found (McNemey and Schrenk 1960). Vascular congestion was reported in the skin of guinea pigs after exposure to unknown doses of hydrogen cyanide for 65 minutes (Fairley et al. 1934). 

Ocular Effects. Acute exposure to cyanogen gas produced eye irritation in volunteers (McNemey and Schrenk 1960). Similarly, chronic exposure to cyanide in the working environment caused eye irritation in exposed individuals (Blanc et al. 1985). In addition, exposure to potassium silver cyanide caused ocular opacity in exposed animals, but comeal opacity is also a sign of excessive exposure to soluble silver salts alone. However, when cyanide was applied to a rabbit s eye, keratitis developed regardless of the chemical form of cyanide used (Ballantyne 1983b). 

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