# BAC and Metho fumes **URL:** \ **Category:** Factual Questions\ **Created:** [June 30, 2002, 4:32am UTC](https://boards.straightdope.com/t/bac-and-metho-fumes/116662 "2002-06-30T04:32:16Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![kambuckta](https://avatars.discourse-cdn.com/v4/letter/k/53a042/32.png) [@kambuckta](https://boards.straightdope.com/u/kambuckta)\ **Post date:** [June 30, 2002, 4:32am UTC](https://boards.straightdope.com/t/bac-and-metho-fumes/116662/1 "2002-06-30T04:32:16Z")
If you were using methylated spirits to do some, oh, lets say cleaning glass in an enclosed space, would the ingested fumes be metabolised as alcohol in your body, and would it be possible to detect it with a blood test? I’m not talking about actually drinking the stuff, just asking whether the ‘fumes’ themselves contain alcohol, and whether they can be ‘breathed in’ as such. Ta muchly. ---
**Author:** ![Wikkit](https://avatars.discourse-cdn.com/v4/letter/w/c0e974/32.png) [@Wikkit](https://boards.straightdope.com/u/Wikkit)\ **Post date:** [June 30, 2002, 7:40am UTC](https://boards.straightdope.com/t/bac-and-metho-fumes/116662/2 "2002-06-30T07:40:07Z")
The fumes are alcohol, so inhaling them would probably put it into your blood. The lethal dose is around 1 g/kg, so it’d depend on how long you were around the stuff. “Methanol itself may cause inebriation but by itself in almost completely non-toxic. The methanol is metabolized by alcohol dehydrogenase to formaldehyde and then to formic acid. (…) It is the formic acid that causes the profound metabolic acidosis that is typical of methanol poisoning. The overall mortality of methanol poisoning is approximately 20% and among survivors the rate of permanent visual impairment is 20-25%.” – [http://www.embbs.com/cr/alc/alc6.html](http://www.embbs.com/cr/alc/alc6.html) “Potential Health Effects Inhalation: A slight irritant to the mucous membranes. Toxic effects exerted upon nervous system, particularly the optic nerve. Once absorbed into the body, it is very slowly eliminated. Symptoms of overexposure may include headache, drowsiness, nausea, vomiting, blurred vision, blindness, coma, and death. A person may get better but then worse again up to 30 hours later.” – [http://www.udallas.edu/chemdept/hendrickson/MSDS/methanol\_msds.htm](http://www.udallas.edu/chemdept/hendrickson/MSDS/methanol_msds.htm) One of the biggest uses and dangers of methanol in my world is that it has a very wide range of flamability. So don’t be making sparks. Since you seem to be more worried about not being able to pass a drug test than going blind or dying, it should show up as alcohol if you breathe in enough of it. I’d think it’d be identifiable as methanol on a mass spectrometer/gas chromatagraph (bit outta my league), but how many blood tests go that far? ---
**Author:** ![kambuckta](https://avatars.discourse-cdn.com/v4/letter/k/53a042/32.png) [@kambuckta](https://boards.straightdope.com/u/kambuckta)\ **Post date:** [June 30, 2002, 8:45pm UTC](https://boards.straightdope.com/t/bac-and-metho-fumes/116662/3 "2002-06-30T20:45:23Z")
Thanks Wikkit! I wasn’t concerned about ‘passing’ a blood test 😛 because obviously the amount of ethanol absorbed via fumes would be absolutely miniscule…it was just a question about whether there would be any alcohol AT ALL in one’s system after being around methylated spirits (or other similar solutions). Legal or toxic effects were not really my worry!! ---
**Author:** ![Wikkit](https://avatars.discourse-cdn.com/v4/letter/w/c0e974/32.png) [@Wikkit](https://boards.straightdope.com/u/Wikkit)\ **Post date:** [July 1, 2002, 2:20am UTC](https://boards.straightdope.com/t/bac-and-metho-fumes/116662/4 "2002-07-01T02:20:29Z")
Glad to help. If it’s an option, I’d try to use ethyl alchohol (ethanol) when cleaning in confined spaces, rather than methyl alchohol (methanol). It would work just as well, but there’d be no risk from formic acid. Of course, you’d have to be in this space for a long time to absorb enough methanol to overwhelm your bodies ability to get rid of it. Fruit, home made alcohol drinks, and artificial sweeteners all contain or metabolize into methanol. Just try to keep it under 1 gram per kilogram of body mass. Fun with Methanol: Take a jam (jelly) jar, and drill a half inch hole in the lid. Dump in enough methanol to cover the bottom, put on the lid, and shake it a bit. Put a long match to the hole, and voila, you’ve got a primitive pulse jet combustor. If it runs too long (~10 seconds), it’ll shatter, so do it outside on concrete. Boric acid can be added to the methanol to make the flame green.