Neil
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What level of exposure to methanol is safe?
If you click below...
http://lmgtfy.com/?q=Methanol%2C+msds
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IndependentBoffin
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The MSDS does not say if exposure below the recommended limits results in cumulative damage, or if cumulative damage only starts for exposures near
the limits.
My eyes have been feeling funny about 24 hours after spilling some on my hands, that's all, and I did read elsewhere it can take 16-24 hours for some
symptoms to appear. I had enough to wet my left hand for about 5 seconds before it dried off. Kind of blurry and hard to focus on peripheral stuff.
When I read the MSDS (yes before the OP) it just made me more worried and I had to ask the more experienced chemists here if I was just being
paranoid.
Now whenever I pick up the methanol bottle I'm going to put on gloves, a lab coat and do it outside!
[Edited on 24-4-2011 by IndependentBoffin]
I can sell the following:
1) Various high purity non-ferrous metals - Ni, Co, Ta, Zr, Mo, Ti, Nb.
2) Alkex para-aramid Korean Kevlar analogue fabric (about 50% Du Pont's prices)
3) NdFeB magnets
4) High purity technical ceramics
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ScienceSquirrel
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Mood: Dogs are pets but cats are little furry humans with four feet and self determination! 
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It will depend on the individual.
I have had a lot more exposure to methanol than that during my career as a chemist and probably more exposure as a private individual.
I used to use it as a HPLC solvent by the bucket load and it is still a common constituent of windscreen washer fluid etc.
I am in my late forties now and my eye sight is not as sharp as it was but I can still read 6 point print so I am not going blind due to methanol.
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Neil
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Why don't you call up your local poison control and ask them?
If it is causing damage, it would be to your advantage to find out now rather then later.
http://www.epa.gov/chemfact/s_methan.txt
" Pharmacokinetics
1. Absorption - Methanol is readily absorbed after oral,
inhalation, or dermal exposure. Oral doses in humans of
71 to 84 mg/kg resulted in blood levels of 4.7 to 7.6
mg/100 mL of blood within 3 hours (Rowe and McCollister
1981). Inhalation of 500 to 1000 ppm methanol for 3 to
4 hours gave urine concentrations of 1 to 3 mg methanol/100
mL of urine at the end of exposure (Rowe and McCollister 1981). Based on urinary methanol levels, the rate of absorption of the chemical
appears to be proportional to the concentration of vapor inhaled (HSDB 1994). The rate of dermal absorption increased for 35 minutes then decreased
over the next 25 minutes (no other details given) (HSDB 1994). "
Edit: Also I apologize for the asininity of my original post. Hope it's nothing.. but please get your self checked out if you think something could be
wrong...
[Edited on 24-4-2011 by Neil]
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IndependentBoffin
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Quote: Originally posted by ScienceSquirrel  | It will depend on the individual.
I have had a lot more exposure to methanol than that during my career as a chemist and probably more exposure as a private individual.
I used to use it as a HPLC solvent by the bucket load and it is still a common constituent of windscreen washer fluid etc.
I am in my late forties now and my eye sight is not as sharp as it was but I can still read 6 point print so I am not going blind due to methanol.
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OK thanks I feel reassured. I must have been just tired then.
I understand that alcohol dehydrogenase is a bad thing when exposed to methanol because it metabolises methanol to formaldehyde and then formic acid
via aldehyde dehydrogenase.
Does this mean that teetotalers (myself) and people lacking the genes for alcohol dehydrogenase are more resistant to the effects of methanol?
I can sell the following:
1) Various high purity non-ferrous metals - Ni, Co, Ta, Zr, Mo, Ti, Nb.
2) Alkex para-aramid Korean Kevlar analogue fabric (about 50% Du Pont's prices)
3) NdFeB magnets
4) High purity technical ceramics
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Jor
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Funny you ask. I have been wondering this myself.
I recently added a a few hundred mg of malonic acid to about 8mL of methanol and added 1mL of H2SO4. I heated this at 40-50C for 2 hours poured it on
a crystallising dish and took a whiff, I couldn't smell anything so I tried 2 more times. the methanol was warm and I was close with my nose so I
inhaled quite a lot. I knew that this was not enough for ill effects but I read on methanol toxicity that day. It seems that susceptibility varies
widely among individuals, and you cannot use the LD50 as an indicator of danger. Although the average fatal dose is 30-50mL, doses as low as 10mL (one
source states a minimal fatal dose of 15mL of 40% MeOH, wich is 6mL ! ) have resulted in death, but another patient survived 500mL!
However these are amount you will never be exposed to unless you drink it or work with large amounts hot methanol for hours in a poorly ventilated
area.
However, permanent eye damage can already occur with smaller amounts. As long as you work in a well ventilated area I see no risk handling the stuff
unless you spill a lot on your skin. Sniffing it on purpose like I did is not recommended!
If you're really worried, eat lot's of orange juices. This contains folic acid, and this is a cofactor in the metabolism of formic acid (wich is the
toxic metabolite responsible for effects) to CO2.
After 24 hours it's probably already to late to drink a lot of normal alcohol as an antidote as most MeOH will be metabolized to formic acid.
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IndependentBoffin
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Posts: 150
Registered: 15-4-2011
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| Quote: Originally posted by Neil | Why don't you call up your local poison control and ask them?
If it is causing damage, it would be to your advantage to find out now rather then later.
http://www.epa.gov/chemfact/s_methan.txt
" Pharmacokinetics
1. Absorption - Methanol is readily absorbed after oral,
inhalation, or dermal exposure. Oral doses in humans of
71 to 84 mg/kg resulted in blood levels of 4.7 to 7.6
mg/100 mL of blood within 3 hours (Rowe and McCollister
1981). Inhalation of 500 to 1000 ppm methanol for 3 to
4 hours gave urine concentrations of 1 to 3 mg methanol/100
mL of urine at the end of exposure (Rowe and McCollister 1981). Based on urinary methanol levels, the rate of absorption of the chemical
appears to be proportional to the concentration of vapor inhaled (HSDB 1994). The rate of dermal absorption increased for 35 minutes then decreased
over the next 25 minutes (no other details given) (HSDB 1994). "
Edit: Also I apologize for the asininity of my original post. Hope it's nothing.. but please get your self checked out if you think something could be
wrong...
[Edited on 24-4-2011 by Neil] |
Thanks, don't worry about the asininity of your OP. I was planning to say I had Googled for the MSDS already but my housemate interrupted me mid post
and when I came back I forgot to say it.
It seems the treatment for methanol poisoning is ethanol or Fomepizole (from a hospital).
I can sell the following:
1) Various high purity non-ferrous metals - Ni, Co, Ta, Zr, Mo, Ti, Nb.
2) Alkex para-aramid Korean Kevlar analogue fabric (about 50% Du Pont's prices)
3) NdFeB magnets
4) High purity technical ceramics
|
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IndependentBoffin
Hazard to Others
Posts: 150
Registered: 15-4-2011
Member Is Offline
Mood: No Mood
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| Quote: Originally posted by Jor | Funny you ask. I have been wondering this myself.
I recently added a a few hundred mg of malonic acid to about 8mL of methanol and added 1mL of H2SO4. I heated this at 40-50C for 2 hours poured it on
a crystallising dish and took a whiff, I couldn't smell anything so I tried 2 more times. the methanol was warm and I was close with my nose so I
inhaled quite a lot. I knew that this was not enough for ill effects but I read on methanol toxicity that day. It seems that susceptibility varies
widely among individuals, and you cannot use the LD50 as an indicator of danger. Although the average fatal dose is 30-50mL, doses as low as 10mL (one
source states a minimal fatal dose of 15mL of 40% MeOH, wich is 6mL ! ) have resulted in death, but another patient survived 500mL!
However these are amount you will never be exposed to unless you drink it or work with large amounts hot methanol for hours in a poorly ventilated
area.
However, permanent eye damage can already occur with smaller amounts. As long as you work in a well ventilated area I see no risk handling the stuff
unless you spill a lot on your skin. Sniffing it on purpose like I did is not recommended!
If you're really worried, eat lot's of orange juices. This contains folic acid, and this is a cofactor in the metabolism of formic acid (wich is the
toxic metabolite responsible for effects) to CO2.
After 24 hours it's probably already to late to drink a lot of normal alcohol as an antidote as most MeOH will be metabolized to formic acid.
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Thanks. I'm off to eat some oranges. You, sir, need to go get a stiff drink! 
Haha ironic I just got my status upgraded after my 50th post from "Harmless" to "Hazard to Self". Talk about timing 
[Edited on 25-4-2011 by IndependentBoffin]
I can sell the following:
1) Various high purity non-ferrous metals - Ni, Co, Ta, Zr, Mo, Ti, Nb.
2) Alkex para-aramid Korean Kevlar analogue fabric (about 50% Du Pont's prices)
3) NdFeB magnets
4) High purity technical ceramics
|
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