H&S Dangerous Gases
Phosgene (deadly) gas
from Brake Cleaner, heat and Argon (e.g. MIG/TIG welding)
Read the back of the can.. if it says chlorinated then read on!
Freon (regrigerant)
combined with combustion products can produce phosgene!
Quote form general forum link below
Been exposed to phosgene twice without really knowing what it was and yes it is very ver bad stuff. one time years ago when we simply drained refrigerant without recovering it i was draining a auto a/c and left the hoses under the hood while i pulled the car into the shop. simply letting the freon near the air inlet was enuf. walked by the rear of the car and my lungs froze up. other time was also drining freon near a salamander type heater.
lucky to live i guess.
Electrical Contact cleaners
Good electrical contact cleaners (chlorinated ones) can also produce this phosgene gas
Overheated Teflon (PTFE)
The bad stuff from overheated teflon (PTFE) and the other fluorinated plastics (eg in high temp o rings) is hydrofluoric acid, not phosgene.
HF is well capable of penetrating through gloves and then through your flesh. by the time you feel tingling the damage is done, and that flesh and bone will probably die, once it does start to hurt, the pain is supposed to be out of all proportion to the size of the affected area.
as a gas, it will not only burn your lungs but will also react with calcium in your body, potentially causing a heart attack.
HF is an ingredient of some of the passivating solutions for cleaning stainless, and the solutions for cleaning car wheels and windscreens. lovely stuff. Not!
Welding brazing fuxes
Some welding and brazing fluxes contain fluorides. Exposing them to sulphuric acid will liberate HF (sulphuric acid displaces (almost) all other acids from their salts)
Fire Extinguishers
The worst fire extinguishers for phosgene were the Halon / Carbon Tetrachloride ones.
Dry Cleaning Solvents
Dry cleaning solvents are all bad when overheated, a poster on a british HSM board gave an example of almost gassing himself when he poured CCl4 on a wastebin fire in his workshop.
