When R-12 vapor is drawn into an open flame, what can it break down into?
Safety · EPA 608 Type I. The correct answer, and the reasoning behind it.
Decomposition products of refrigerants at high temperatures, and safe handling.
The question
When R-12 vapor is drawn into an open flame, what can it break down into?
- Phosgene, hydrochloric acid and hydrofluoric acidCorrect answer
- Only harmless carbon dioxide and plain water vapor
- Pure chlorine gas and ozone
- Harmless nitrogen and oxygen
Why “Phosgene, hydrochloric acid and hydrofluoric acid” is correct
At high temperatures, CFCs and HCFCs decompose into toxic and corrosive products, including hydrochloric acid, hydrofluoric acid and phosgene gas. That is why refrigerant must be kept away from flames and red-hot surfaces.
Source: EPA: Test Topics
Why the other answers are wrong
- Only harmless carbon dioxide and plain water vapor — That is what hydrocarbons produce when they burn; R-12 contains chlorine and fluorine.
- Pure chlorine gas and ozone — Flame decomposition does not produce ozone, and the main concern is acids and phosgene.
- Harmless nitrogen and oxygen — R-12 contains no nitrogen, and its breakdown products are toxic.
Practice more of this
More EPA 608 Type I practice questions, or see every EPA 608 practice test.
Unofficial, not affiliated with the EPA or any EPA-approved certifying organization. Questions are original practice written from public EPA material, not real exam questions.