This case study demonstrates the danger of inhaling odourless refrigerants.
An engineer, on site to change a compressor shaft seal, recently suffered from what IS believed to be the effects of inhaling an odourless refrigerant, R408A. The incident resulted in the engineer feeling unwell, with symptoms such as dizziness, heart palpitations and nausea. He recovered within two or three hours.
After pumping down the compressor, the engineer closed the suction, discharge and oil stop valves and electrically isolated the compressor, before starting to remove the drive coupling and guard. This work involved working near to the ground and close to the shaft seal. During this time the engineer was unaware that the suction stop valve was passing and that as a result refrigerant was still escaping from the shaft seal. By the time the engineer was ready to remove the seized coupling using a couple of Turbo Torches, it would appear that he had been inhaling a refrigerant rich atmosphere for some considerable time. As the engineer applied heat to the coupling he began to feel ill. Fortunately, he stopped work and sat outdoors in the fresh air for a while to recover.
When the engineer returned to the job, he carried out a leak test and discovered the passing suction stop valve.
It is likely that it was the effects of refrigerant inhalation and not the products of combustion that affected the engineer.
Inhalation of R408A, as with other common refrigerants such as R22, may cause cardiac arrhythmia - a variation in the normal rhythm of the heart (heart palpitations) - and may also have a narcotic effect, which can lead to dizziness, headaches, and ultimately unconsciousness. Whereas, the products of combustion are much more toxic than the refrigerant itself but are much more readily detected as they have a very pungent odour and are very acidic, causing immediate and severe irritation to the nose, throat and lungs. Since the engineer did not smell or feel any of these symptoms, the evidence points to the refrigerant itself.
REMEMBER in your own interest when working in or entering a space where you suspect a leak, be careful
• Try to confirm if refrigerant is present in the atmosphere - halide lamp, electronic leak detector, automatic plant room leak detection.
• Carryout a confirmation leak test before continuing, do not assume that valves are holding fast.
• Cure leaks or isolate plant.
• Increase levels of ventilation particularly at low level (open doors and windows, turn on ventilation).
• Ask a second person to observe you from a safe place. Instruct them in what action to take if you appear to be in distress.
• Do not weld, burn or heat in the presence of refrigerant, as the toxic, pungent, acidic gases produced are harmful if inhaled.
• Remember that other gases displace air (Other refrigerants, Nitrogen, argon used for welding, etc.)
• If you suspect that an area may be depleted of oxygen do not enter. Call for assistance and conduct a full assessment of the situation. Considerable resources may be required such as oxygen detectors and breathing apparatus.