- ANo danger
- The refrigerant may decompose into toxic gases including phosgene
- CThe refrigerant will explode
- DIt's an approved leak detection method
Correct answer
The refrigerant may decompose into toxic gases including phosgene
Why
When exposed to open flame, many refrigerants decompose into toxic gases including phosgene (a chemical warfare agent), hydrogen fluoride, and hydrogen chloride.
The concept behind this question
The hazards on this exam are the ones that actually injure technicians. Refrigerants displace oxygen in confined spaces, so asphyxiation is a genuine risk in a mechanical room with a leak. Liquid refrigerant causes frostbite on skin and eye contact, so gloves and eye protection are not optional. Never charge with an open-flame or heat source nearby, never use compressed air or oxygen to pressure-test, and never exceed a cylinder's fill limit — cylinders are filled to 80% by weight precisely so there is room for liquid to expand.
More questions on this topic
- What are the two factors that, if present, are most likely to lead to an explosion with hydrocarbon refrigerants?
- What hazard exists when using nitrogen to pressurize a system for leak testing?
- Why should oxygen or compressed air never be used to pressurize a refrigeration system?
- What should you do if a large refrigerant leak occurs in an enclosed space?
- What personal protective equipment should be worn when handling refrigerants?
- What type of equipment should be used to detect refrigerant leaks?
Exam-style practice question. Not an official EPA exam question.