Chemical Safety Article

[fjk]

Dont mean to be a doubting Thomas,But people are taking this guys post about his bad experience and treating it like the guy did a controlled scientific experiment.Just like the alleged workers pissing in the Corona beer one person starts it and everyone takes it for fact.Mike

True

But the points (at least, the points that _I_ get) are

- pay close attention to the stuff we use (in the case of this article,
brake cleaner). Some of it can be Real Bad JuJu.

- while there may be mystery gunk on the metal already --- why
add to the gunkiness?

frank

[enlpck]

Isnt most brake cleaner non chlorinated now by law?.Mike

No. They no longer contain CFC's (ChloroFlouroCarbons), but most still contain chlorinated solvents. If the listr of ingredients or the MSDS has any chemical containing "chloro" (or related word parts), it is chlorinated.

For example, the current brakleen: http://www.fastenal.com/web/msds/getmsds.ex?sku=63337

[Laiky]

The reaction occurs where chlorinated brake cleaner Argon and heat combine. The guy was seriously screwed up by the reaction, and from the story it was a tiny bit of gas. Take the warning and be safe instead of sorry. Non-chlorinated brake cleaner is easy to find, buy why bother when you can use isopropyl alcohol?

[enlpck]

Not argon. The UV and/or high arc temperature (either may begin the process) facilitates the breakdown of many chlorinated solvents to form phosgene in the lower temperature regions outside, but near, the arc.

The wikipedia page on phosgene is reasonably accurate. See also http://www.bt.cdc.gov/agent/phosgene/basics/facts.asp
http://www.cdc.gov/niosh/docs/81-123/pdfs/0504.pdf
http://www.cdc.gov/Niosh/idlh/75445.html

Note that the odor is not generally apparent until the concentration is about 0.5PPM, well in excess of the PEL of 0.1PPM, and is near the IDLH value of 2PPM. (PEL Permissible Exposure Limit; IDLH: Immediately Dangerous to Life and Health)

[fjk]

from the story it was a tiny bit of gas.

Phosgene is seriously bad stuff... Like I said in an earlier post,
it really gained notoriety in WW1 as a chemical warfare agent.
If it was used in CW, then it's safe to assume that it's pretty
bad, and pretty bad in pretty small doses...

Btw, organo-phosphates (phosphorus based organic chemicals)
are another big family of CW compounds.They are used today
in insecticides (parathion, malathion, etc). Given the bad-effects
in small-doses properties that make for a good CW agent,
one might also wish to take some extra care when working
with material that might have these things on/around them.

As what's-his-name said "let's be careful out there"

Frank

[Laiky]

Not argon. The UV and/or high arc temperature (either may begin the process) facilitates the breakdown of many chlorinated solvents to form phosgene in the lower temperature regions outside, but near, the arc.

The wikipedia page on phosgene is reasonably accurate. See also http://www.bt.cdc.gov/agent/phosgene/basics/facts.asp
http://www.cdc.gov/niosh/docs/81-123/pdfs/0504.pdf
http://www.cdc.gov/Niosh/idlh/75445.html

Note that the odor is not generally apparent until the concentration is about 0.5PPM, well in excess of the PEL of 0.1PPM, and is near the IDLH value of 2PPM. (PEL Permissible Exposure Limit; IDLH: Immediately Dangerous to Life and Health)

I stand corrected, chlorinated solvents and High Temp/UV