[hvac01453]

Now this may sound like a stupid question but, I work in the HVAC community and it was long rumored that refrigerant  released under a flame releases phosgene gas.  I read somewhere this was false and if anything it may be Hydrofluoric acid gas...all mechanics know, is that small wifs of this vapor under a flame will sting the heck out of your nose while brazing or soldering...  I would like to know what  is it thats stinging my nose so badly, it can't be phosgene? Is it that tough to figure out?

[Hunter2]

Under a flame, Halogenalkans will decompose to HX, in this case HF and HCl and in some circumstances also to phosgen COCl₂ or fluorophosgen or COF₂.

[hvac01453]

so what your saying is "I don't know?"
1.)What is HX, HCL and HF?
2.) What is meant by "in some circumstances."
3.)What is the difference between  COCL2 and COF2. When I hear phosgene, I hear  WWI gas, blindness and respiratory failure.  is one poisonous and the other not???   I know a small difference of molecules makes a world of difference...
4.)  What is it, that burns ones nose when soldering?

[Hunter2]

so what your saying is "I don't know?"
1.)What is HX, HCL and HF?
2.) What is meant by "in some circumstances."
3.)What is the difference between  COCL2 and COF2. When I hear phosgene, I hear  WWI gas, blindness and respiratory failure.  is one poisonous and the other not???   I know a small difference of molecules makes a world of difference...
4.)  What is it, that burns ones nose when soldering?

1. yes, the X stands for the halogen atom
2. Depends of temperature, presense of amount of oxygen, etc.
3. Both are phosgen type, where the flourine one more dangerous is, Yes these chemicls where used as warfare gas in WWI.
4. the mixture of all , it is acidic and poison