Difference between revisions of "H&S Dangerous Gases"
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Symptons of zinc or lead fume inalation can be flu like, sickness, vomiting, nausea, depression, edgy, easily niggled, tired etc | Symptons of zinc or lead fume inalation can be flu like, sickness, vomiting, nausea, depression, edgy, easily niggled, tired etc | ||
[http://www.finishing.com/144/51.shtml Here is some discussion, with varying viewpoints] | |||
==Other dangers== | ==Other dangers== | ||
Revision as of 13:28, 5 November 2009
Phosgene and other deadly gases
Brake Cleaner (chlorinated)
Phosgene (WW1 trench warfare gas) can be produced from unevaporated Brake Cleaner and Heat. With Argon (e.g. MIG/TIG welding)as well, phosgene can flash off and incapacitate you in seconds!
Read the back of the can.. if it says chlorinated then make sure you know what NOT to do with it... no heat and no other rare gases.
Freon (refrigerant)
combined with combustion products can produce phosgene!
Quote from general links below
Been exposed to phosgene twice without really knowing what it was and yes it is very, very bad stuff. One time years ago when we simply drained refrigerant without recovering it I was draining an 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 enough. Walked by the rear of the car and my lungs froze up. Other time was also draining Freon near a salamander type heater.
Lucky to live I guess.
Electrical Switch/Contact cleaners
Good electrical contact cleaners (chlorinated ones) can also produce this phosgene gas
Generally, if a solvent flashes off clean, removing contaminants, it could well be dangerous used inappropriately
Fire Extinguishers
The worst fire extinguishers for phosgene were the Halon / Carbon Tetrachloride ones.
40 years ago, Navy, we had a foam dispenser aboard ship for oil fires, Diesel boat. Were told that using the foam would create Phosgene gas when it hit hot metal.
Hydrofluoric Acid
Overheated Teflon (PTFE)
Supposedly 450F is the point at which this gets dangerous.. sounds very close to what is achieved in normal bacon and eggs type cooking, or when non-stick frying-pan left on with nothing in it.
Teflon is also a baddie. When heated above 500deg F or so, it can emit dangerous gas. I personally spoke to the guy who discovered this little factoid while working for a nuclear plant. They used to think Teflon was great stuff until this was known.
Your Teflon coated cookware can do this if you leave an empty pan on a burner for a few minutes. Since that time, I've looked specifically for non-coated cookware.
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.
Some car wheel cleaners and passivating solutions
HF (hydrofluoric acid) 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 and brazing fluxes
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)
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.
Oxygen
Oxy/Acetylene welding
Oxygen, is of course a strong oxidising agent. The acetylene provides the hydrocarbon fuel. Fat, oil or grease (hydrocarbons) must never been used in an oxygen rich environment, spontaneous combustion can occur. Most professionals will know this, but is worth anyone around this type of equipment knowing. Greasy hands when opening valves on an oxygen bottle up, etc!
Welding
Zinc plated steel (Galvanised)
Welding through galvanising can produce dangerous fumes. Ditto heating lead products. Ditto some etch-primers and othjer metal treatments. These are not in the Phosgene, HCL deadly class , nor produce long term incapacitation, but shoul;d be avoided all the same. Heavy metals are toxic, don't inhale welding any gases and wash your hand after handling lead/zinc etc. Not a bad idea to wear thin gloves if working glav materials.
Don't smoke in a welding environment
Symptons of zinc or lead fume inalation can be flu like, sickness, vomiting, nausea, depression, edgy, easily niggled, tired etc
Here is some discussion, with varying viewpoints
Other dangers
Please read this whole H&S topic
..which contains several references to dangerous gases that can be produced when welding, MIG, TIG especially but also dangers of Oxy/Acetylene. The most dangerous is Phosgene, so read those items 1.1. 1.2 etc.
