Jor
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Health risks CCl4
I have recently acquired a small amount (30-35mL) of pure carbon tetrachloride. I plan to use this for some experimenting on test tube scale, e.g
extracting Mn2O7 from concentrated sulfuric acid (this is not possible with most solvents, because it will ignite).
But I hear terrible stories about how toxic it is. Probable carcinogen (not proven) and the most serious thing: a very strong liver poison.
My question is, do i really have to worry when I experiment on test-tube scale, in a well ventilated room? I wont do hundereds of experiments, just a
few , maybe 5 total the next few months.
And benzene? i have 250mL commercial reagent grade here, but when I read articles, it is also said that is sooo toxic. But other sources , like my
supplier say it's just dangerous if you're exposed for very long periods at high concentration, not a few exposures.
What do you recommend? Do not open bottle yet, till hood is done (few weeks, we got a delay), or is it toxcity exaggerated and can I do experiments
with those?
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kclo4
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Well, they used to use Carbon Tetrachloride as a fire extinguisher, so.. apparently it took them a while to realize it was bad to breath. This makes
me think its not THAT bad. Also, wasn't it used for dry cleaning?
Of course, I've never played with it and I wouldn't know how bad it was, but dealing with small amounts in a well ventilated area (outside on a windy
day?) probably isn't bad. Same for benzene.
but again, I haven't dealt with any of these substances, however I did have a small amount of Impure CBrCl3 at one time mixed with chloroform.
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not_important
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| Quote: | The Occupational Safety and Health Administration (OSHA) set a limit of 10 ppm for carbon tetrachloride in workplace air for an 8-hour workday,
40-hour workweek.
Studies in humans have not been able to determine whether or not carbon tetrachloride can cause cancer because usually there has been exposure to
other chemicals at the same time. Swallowing or breathing carbon tetrachloride for years caused liver tumors in animals. Mice that breathed carbon
tetrachloride also developed tumors of the adrenal gland.
High exposure to carbon tetrachloride can cause liver, kidney, and central nervous system damage. These effects can occur after ingestion or breathing
carbon tetrachloride, and possibly from exposure to the skin. The liver is especially sensitive to carbon tetrachloride because it enlarges and cells
are damaged or destroyed.
Kidneys also are damaged, causing a build up of wastes in the blood. If exposure is low and brief, the liver and kidneys can repair
the damaged cells and function normally again. Effects of carbon tetrachloride are more severe in persons who drink large amounts of alcohol.
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In general the danger is from acute exposure to high concentrations, high enough to be annoying, or from long term exposure to low levels, long term
meaning months or years.
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ycheff
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Breathing big amounts of carbon tetrachloride can cause edema of lungs up to finis letalis
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a_bab
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CCl4 is still used for removing grease; experimenting without having your nose in the testube should be safe.
As for benzene, it was used for many years in school labs and although it is a know carcinogen, dying from cancer caused by it it involves either a
bath in the stuff , or years of working with it.
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woelen
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What a_bab is telling is true, but take one other thing into account.
A one-time exposure to benzene won't kill you.
A one-time exposure to carbon tetrachloride won't kill you.
A one-time exposure to ... won't kill you.
A one-time exposure to ... won't kill you.
A one-time exposure to ... won't kill you.
A one-time exposure to ... won't kill you.
...
...
...
A one-time exposure to ... won't kill you.
But what is the effect of all those one-time exposures added to each other? Being exposed to benzene for 10 times or being exposed to 10 different
chemicals of comparable carcinogenity/toxicity may have approximately the same effect.
So, in general you should not say how much exposure do I have to chemical X or chemical Y, but you should ask yourself how many exposures do I have,
regardless the chemical? If you are in the home-lab every day for e.g. 2 hours and you don't work carefully and you breathe organic solvent vapors
every day (and some of these days you breathe some nastier stuff like benzene or carb. tet.), then there certainly may be a long-term effect. For this
reason I hardly do any chemistry with organic solvents, except the ones which certianly have no systemic poisoning risks (such as acetic acid,
ethanol, acetone and a few others).
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vulture
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| Quote: |
Being exposed to benzene for 10 times |
Everybody who's driving a gasoline powered car in europe is exposed to approximately one liter of benzene during every fill up.
I'm not even going to start about what smokers inhale. Or painters.
If all that stuff was as toxic as some claim, our parents and grandparents would have been dead and buried twenty years ago. Just don't voluntarily
inhale the stuff and you'll be fine.
[Edited on 26-10-2008 by vulture]
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