Sciencemadness Discussion Board

Accidental phosgene gas exposure,near terminal!

grndpndr - 22-8-2009 at 15:40

Reading this on another forum a link to the story.Briefly a welder used to final part cleaning with another cleaner used brake spray cleaner as they were out of his carb cleaner.Apparently the theory went some of the brake cleaner fuid failed to evaporate due to deep pitting of the metal where it collected.Heat gfrom the welding torch caused immediated decomp or the remaining brake cleaner to Hydrogen chloride and phosgene gas.

Immediate death can be caused by as little as 2ppm, symptoms can be delayed 6-48hours during which time this individual had extreme lung pain,kidney pain etc etc.3days after the fact his urine turned brown indicating kidney failure at which time he sought medical aid.Of course thers no antidote for phosgene poisoning just supportive and pallitive care while you live/ die.

Fortunately or not whatever the person involved feelings he may have said hed rather have succumbed since permanent lung damage and kidney,liver,,pancreas damage occured.lung damage resulting in COPD and eventual slow drowning all the while carry 02 bottles.


[Edited on 22-8-2009 by grndpndr](Revised phosgene toxicity)


[Edited on 22-8-2009 by grndpndr]

BromicAcid - 22-8-2009 at 18:26

What is the purpose of this post? To me it looks like fear mongering. Many people here know that chlorinate cleaners can break down into phosgene in contact with flame.

Quote:
Immediate death can be caused by as little as 2ppm, symptoms can be delayed 6-48hours during which time this individual had extreme lung pain,kidney pain etc etc.3days after the fact his urine turned brown indicating kidney failure at which time he sought medical aid.Of course thers no antidote for phosgene poisoning just supportive and pallitive care while you live/ die.


From "Phosgene and Related Carbonyl Halides" (T.A. Ryan, C. Ryan, E.A. Seddon, K.R. Seddon):
Quote:
Clearly, there are no sharp boundaries at which concentrations of phosgene are "safe" and at which some are "dangerous" to the human condition...


Toxicity varies based on weight, age, condition of the lungs, etc. Still, a chart is given in the text lists 25 ppm as dangerous for short exposures, short exposures in this case defined as 30 minutes to 1 hour. Fatal for short exposure is listed as being >50 ppm. Still, these numbers are very low, just much higher than the 2 ppm you list. Two ppm wouldn't have any knockdown power at all, it's not even until 3 ppm that phosgene starts to cause irritation to the throat. At any dangerous concentration it's not just irritation to the throat, >10 ppm causes uncontrollable coughing, horrible burning of the eyes, and other effects. Although phosgene does have a latent period pulmonary edema is the main concern, not kidney failure. Phosgene doesn't really enter the blood so can't make it to the kidneys however it is believed to be metabolite of chlorinated hydrocarbons which tends to destroy the liver and kidneys. Being that that is the case it seems like the person suffering the symptoms may well have been dealing with a side effect of the chlorinated hydrocarbons themselves and not phosgene directly. Strangely enough the text referenced above lists several antidotes for phosgene exposure, however as far as I know none of them are accepted methods of treatment. Due to the odor of phosgene and the detection limits I really couldn't imagine someone sticking around and welding for any period with that overwhelming smell taking a baseball bat to their senses.


[Edited on 8/23/2009 by BromicAcid]

Phosgene gas/Fear mongering?

grndpndr - 23-8-2009 at 07:15

Pardon the inexperience since "most" here know the dangers my concern wasnt warranted apparently.Other than those who arent aware of the problem it may have been of help to them or food for thought but fear mongering! So then any warnings concerning labs
that are well known as are the dangers inherent is fear mongering and shouldnt be mentioned? Why then are you so concerned about my post and not others that mention hazards.Mine is information not worth knowing and is labeled fear mongering even though it could be fatal.Lets follow your lead and label warnings as fear mongering, injury and fatalitys be damned.

Your way out of line with the fear mongering crap i suggest you tell it to someone in authority who believes that my words were "fear mongering"
rather than concern for others and let me know when you locate that person who remotely agrees with you.

grndpndr - 23-8-2009 at 07:32


OSHA states the IDLH (immediately dangerous to life and health) as 2ppm.short exposure to 50PPM may result in rapid fatality.

Im not fear mongering nor am I minimizing the danger as you seem to be doing.I pointed out a possible danger folks should be aware of .If thats fear mongering then most of these labs are engaging in fear mongering by pointing out hazards.Find someone in authority who agrees with you or get off my ass.Im attempting to do some good whats the purpose of your post? Attempt to shit on me for trying to be of service?

[Edited on 23-8-2009 by grndpndr]

Mr. Wizard - 23-8-2009 at 07:35

THIS JUST IN FROM RELIABLE SOURCES!!! CARBON MONOXIDE CAN BE LETHAL!!

Is phosgene any more lethal now than when it was used as a war gas in 1914?

[Edited on 23-8-2009 by Mr. Wizard]

grndpndr - 23-8-2009 at 08:14

Only if its peacetime,your a welder, and your not wearing protective NBC gear because your not expecting lethal gas attack exposure then yes its far more lethal to the welder than the gas mask equipped soldier expecting gas attack.

Why dont you attack Roscoe or others for posting the dangers of nitration fumes over and over and how lethal they can be when "most" of us know that fact?Isnt he and others "scaremongering" with thier warnings or is it you figure im fair game for a sunday morning?E+W down?You sound like E+W refugees?

In any event Im far to old to be playing with children.

[Edited on 23-8-2009 by grndpndr]

BromicAcid - 23-8-2009 at 08:28

First off, I didn't use any profanity, backed up my thoughts with hard numbers and references, and tried to match you point for point where I was coming from.

Secondly, although it is true that a few breaths of a very high concentration of phosgene has a knockdown potential, but most of the statistics out there are influenced by the fact that at one time it was a war gas.

You bring up a good point though. Take for example some of the flammable gasses. Many of their IDLH values are set at 10% of their lower explosive limits. Propane is an asphyxiant, but it has an IDLH of 2100 ppm, that's less than 0.22% of the air you breath, at these concentrations the asphyxiant properties are nill. That is because the IDLH like most of these offical numbers are legal numbers, they are derived in order to cover an empolyers butt. They are based on scientific fact to some extent but history of the compound plays a major role. I tried to reference a different source to show the great disparity between what NIOSH and OSHA numbers may say vs. what literature tells us. Due to WWI we have plenty of information on the toxicity of phosgene and its effects on the human body.

Third, I couldn't tell if you were quoting the article, summarizing, or what. You mention a link but did not provide it. Again, my beef was specifically with the 2 ppm number. Let me reiterate, phosgene is a dangeous poisonous gas. Just not so much as people make it out to be.

A plethora of links to phogene being generated during welding:

http://oeh.informaworld.com/soeh/content~content=a778879101~...
http://www.osha.gov/doc/outreachtraining/htmlfiles/weldhlth....
http://www.brewracingframes.com/id75.htm
http://www.safework.sa.gov.au/uploaded_files/gs33i.pdf
http://www.chestjournal.org/cgi/reprint/99/1/263a.pdf?ck=nck
(Above link is an interesting attempt to recreate welding with chlorinateds present that failed to make phosgene. Also displays that the real dangers is from days of exposure to amounts of phosgene just above the odor threshold, but then again, that only can occur in areas with crappy ventelation)
http://emedicine.medscape.com/article/820649-overview
(Good article on toxicity of phosgene, mentions welding, also covers what the real lethal limits are.)
http://www.dow.com/webapps/lit/litorder.asp?filepath=gco/pdf...
(Dow's offical stance on the subject with graphs of phosgene / HCl concentration over time with different chlorinated solvents)

Really I guess what it was that generated by passionate response more than anything is that you didn't give a good jumping point. Where was the discussion potential there?


grndpndr - 23-8-2009 at 09:02

The intent was not to start discussion per se simply pass on information that was new to me and hopefully cause some
reflection on possible dangers that we may not be aware of
and in the process hopefully prevent someone some grief.The title may have been a bit much on reflection and appear as scaremongering but nothing could be further from the truth.
My only intent was to have people give an extra thought before acting. Regards

As for toxicity, sources for the first post I relyed on the article
secondarily I checked OSHAs reccomendations.In any event Ive taken up far more time/grief than I had anticipated for a simple warning.If the reward for concern is what ive experienced here
then I for one will pass on any further warnings that may affect
the members.Not that I feel my input so valuable I just never expected a slash and burn response to what was meant to be
helpful information.Regards and out

Magpie - 23-8-2009 at 09:46

grndpndr, I appreciate your post because I sometimes feel that we home chemists, including myself, take the health risks of our hobby too casually. When a real-life accident occurs, like the one you have just pointed out, the hazards should become palpable, even to the most brazen kewl.

Until reading the many warnings about NO2 on this forum I had no idea of its toxicity. As a young person I thought it was fun to dissolve pennies in nitric acid and watch the brown fumes, paying no attention to the fact that I was breathing some of it too. I just thought it smelled interesting.

[Edited on 23-8-2009 by Magpie]

zed - 30-8-2009 at 16:09

Phosgene poisoning is indeed a hazard.

Less of a problem now than it used to be. But, still a potential problem.

Carbon tetrachloride fire extinguishers used to be commonplace. Carbon tet. plus fire....Equals... Phosgene!

Well, Carbon tet., isn't used much these days. So you would figure, problem solved.

Maybe not so.

I was trying to un-bolt something a few years back, and it wasn't un-bolting easy.

As I was alternately, heating my bolt with a torch, and freezing it with sprayed freon, it suddenly occurred to me, that this might be pretty hazardous.

CCl4 and CCl2F2, are kissing cousins. Generating Phosgene, or a Phosgene homolog, via heat and freon, seems quite possible.

http://www.interfire.org/features/legalview.asp?date=0813200...

[Edited on 31-8-2009 by zed]

[Edited on 31-8-2009 by zed]

The WiZard is In - 15-4-2010 at 12:44

Quote: Originally posted by BromicAcid  
What is the purpose of this post? To me it looks like fear mongering. Many people here know that chlorinate cleaners can break down into phosgene in contact with flame.
[Edited on 8/23/2009 by BromicAcid]



I remember when NY City subway cars had carbon tetrachloride
fire extinguishers. Me thinks this is the last place one would want
CCl4 and hot metal in a peopled confined space!