Ok, so the claim is that
Quote:
tetrachloroethylene, the active ingredient in brake cleaner, when combined with heat (like from welding) and argon gas (used in MIG and TIG welding) makes phosgene, a potent and deadly nerve gas.
I'm no chemical engineer, but let's look at this grossly.
"phosgene" is Carbonyl dichloride, i.e., C-O-Cl2 (Carbon, Oxygen and 2 chlorine atoms).
Obviously carbon and oxygen are overwhelmingly common here on Earth on an almost infinite variety of combinations
Tetrachloroethylene is Cl2C (or CCl2) . It is a colorless liquid widely used for dry cleaning of fabrics, hence it is sometimes called "dry-cleaning fluid."
According to Wikipedia (FWIW)
Quote:
Upon ultraviolet (UV) radiation in the presence of oxygen, chloroform slowly [emphasis mine] converts into phosgene by a radical reaction. To suppress this photodegradation, chloroform is often stored in brown-tinted glass containers. Chlorinated compounds used to remove oil from metals, such as automotive brake cleaners, are converted to phosgene by the UV rays of arc welding processes.
So, on the face of it, this sounds pretty bad. But...
Anyone who has used some spray can with Tetrachloroethylene (like brake cleaner) knows that the stuff evaporates almost instantaneously. Once evaporated, it's not there to combine under arc welding into "phosgene".
I think this is an "old wives tale" because otherwise, there'd be many deaths reported of guys using TIG/MIG (arc) welders around brake cleaner!
I'm not saying lean over and breathe deeply while you are both spraying brake cleaner and welding something, but that scenario is not real.
Craig
This Post was from: https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=118726