Working in HFC and HCFC Machinery Rooms Safety Alert –

Guidance Note 21 from the Institute of Refrigeration

Workers asphyxiated in refrigeration plant rooms

It has recently been reported that an incident took place in a shopping centre basement plant room where four workers were asphyxiated. The atmosphere was thought to have had a high concentration of refrigerant following a leak from the refrigeration plant. The plant was reported to have been a centrifugal chiller containing refrigerant R-123. Any non-toxic, non-flammable HFC or HCFC might have had the same effect, because these refrigerants are heavier than air and if they leak into an unventilated area such as a basement they can accumulate and create an oxygen deficient atmosphere. It is unclear what ventilation, if any, the basement plant room had in this instance.

A similar incident occurred in 1991 in Alaska where there was a serious leak of R22 in the refrigeration plant room. The plant room was located in a leisure centre which included an R22 ice rink and a swimming pool. A manager died after entering the plant room wearing a cartridge-type respirator. Two other personnel were injured and two members of the public had to be rescued from the swimming pool.

Why don’t people notice they are in danger and flee to a safe place?

People die in oxygen deficient atmospheres (where there is less than the normal (21% Oxygen in air) because the body and brain naturally protects itself by shutting down rather than invoking a fight or flee response. Therefore, typically, a person will be quite unaware that their behaviour is abnormal or that they are in danger. There will be defects in their judgement and reasoning with a feeling of confidence, hilarity, belligerence, reduction in vision, weakness of arms and legs leading imperceptibly to unconsciousness. If the oxygen level is low enough death can follow rapidly.