An accidental discharge of a Halon 1301 total flooding fire extinguishing system

An accidental discharge of a total flooding Halon 1301 fire extinguishing system is described. The release of the Halon was accompanied by a sudden very loud noise, considerable air turbulence and a dense fog, resulting in worker anxiety and loss of visibility. The workers in the area at the time of the discharge reported higher frequencies of lightheadedness, headache, nasal complaints and disorientation than those entering the area later. Halon 1301 usually is regarded as having a low toxicity, although at concentrations above those used in occupied spaces, effects on consciousness and cardiac rhythm have been reported. In the present report no significant illness or injury due to the Halon exposure was found. A fine oily deposit found on horizontal surfaces in the area subsequent to the discharge consisted of mineral oil and iron, suggesting that this material was scoured out of the piping as the Halon discharged. The disorientation and anxiety produced by an accidental discharge can be minimized through education programs designed to ensure that personnel know what to expect and how to abort the discharge if it results from a false alarm. Situations leading to triggering of fire detectors by events other than fires should be investigated and reduced.