PUR burning produces Hydrogen Cyanide (HCN) among the most rapidly acting of all known poisons
westcliff-incident-report-part-a
The first time a PUR fire caused major issues in Australian Coal Mines was at Westcliffe Colliery in NSW in December 1986.
This occurred when PUR was used as a cavity fill while trying to form a false roof in the Longwall.
The fire was put out by on site Deputy (ERZC) in the panel and then on shift Mines Rescue trained mine workers
No one was injured or killed during the fire fighting operations but years later a number of the men involved in the fire fighting developed rare cancers and died. Investigations have not directly identified a link between the event and the deaths but it is identified as a cancer cluster.
HCN is among the most rapidly acting of all known poisons. Absorption occurs by all routes; the mechanism of action is inhibition of cellular respiration. The respiratory, central nervous, and cardiovascular systems are the primary targets of an acute exposure. Information on human exposures was limited to exposures to high concentrations for short time intervals, poorly documented accidental exposures, and chronic occupational exposures.
According to Hartung (1994), a few breaths at “high concentrations” may be followed by rapid collapse and cessation of respiration. If the exposure continues, unconsciousness is followed by death. At much lower concentrations, the earliest symptoms may be numbness, weakness, vertigo, some nausea, and rapid pulse. The respiratory rate increases initially and at later stages becomes slow and gasping. Chronic exposures have been related to thyroid enlargement. Cardiac effects include electrocardiogram changes (HSDB 2000). HCN is not considered a lacrimator (Weedon et al. 1940). Should individuals survive the acute phase of HCN intoxication, recovery can be uneventful and without permanent sequelae.
