# Would denatured alcohol even be dangerous to consume? **URL:** \ **Category:** Factual Questions\ **Created:** [September 6, 2012, 7:27pm UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894 "2012-09-06T19:27:16Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![grude](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@grude](https://boards.straightdope.com/u/grude)\ **Post date:** [September 6, 2012, 7:27pm UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/1 "2012-09-06T19:27:16Z")
If it is 90% ethanol and 10% methanol, would the methanol even matter since the body selectively metabolizes ethanol? Imagine a hard core alcoholic, would their body ever run out of ethanol to selectively metabolize? Or am I totally off track here? ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [September 6, 2012, 7:49pm UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/2 "2012-09-06T19:49:00Z")
“denatured” alcohol doesn’t always contain methanol. it might be some other substance that would make it unfit to drink. They used to use benzene, I understand. Even if the adulterant is methanol, I wouldn’t go drinking methanol. It’s toxic, and consumption can cause blindness: > [@](#): > > Toxicity > > Methanol has a high toxicity in humans. If ingested, for example, as little as 10 mL of pure methanol can cause permanent blindness by destruction of the optic nerve, and 30 mL is potentially fatal,[12] although the median lethal dose is typically 100 mL (4 fl oz) (i.e. 1–2 mL/kg of pure methanol[13]). Toxic effects take hours to start, and effective antidotes can often prevent permanent damage.[12] Because of its similarities in both appearance and odor to ethanol (the alcohol in beverages), it is difficult to differentiate between the two (such is also the case with denatured alcohol). > **[Methanol](https://en.wikipedia.org/wiki/Methanol)** > > Moderately toxic for small animals – Highly toxic to large animals and humans (in high concentrations) – May be fatal/lethal or cause blindness and damage to the liver, kidneys, and heart if swallowed – Toxicity effects from repeated over exposure have an accumulative effect on the central nervous system, especially the optic nerve – Symptoms may be delayed, become severe after 12 to 18 hours, and linger for several days after exposure > 385 °C (725 °F; 658 K) > Methanol (also called methyl alcoh... ---
**Author:** ![grude](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@grude](https://boards.straightdope.com/u/grude)\ **Post date:** [September 6, 2012, 7:52pm UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/3 "2012-09-06T19:52:23Z")
Yea to be clear I have no interest in drinking denatured alcohol, I was just curious since the antidote for methanol poisoning is ethanol basically. You keep the body busy metabolizing ethanol until the methanol is passed unmetabolized, it is rather strange methanol was chosen as an adulterant. ---
**Author:** ![Szlater](https://avatars.discourse-cdn.com/v4/letter/s/90ced4/32.png) [@Szlater](https://boards.straightdope.com/u/Szlater)\ **Post date:** [September 6, 2012, 7:53pm UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/4 "2012-09-06T19:53:35Z")
> [@CalMeacham](#): > > “denatured” alcohol doesn’t always contain methanol. it might be some other substance that would make it unfit to drink. They used to use benzene, I understand. > Even if the adulterant is methanol, I wouldn’t go drinking methanol. It’s toxic, and consumption can cause blindness: > > [Methanol - Wikipedia](http://en.wikipedia.org/wiki/Methanol) My aunt told me of a coworker in her lab who used to enjoy an occasional cheeky nip from an ethanol wash bottle… One day the technician who filled the wash bottles filled the ethanol bottle with methanol by mistake and the crafter drinker not realising that his tipple was now toxic went blind as a result. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [September 6, 2012, 8:08pm UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/5 "2012-09-06T20:08:37Z")
_Basically_, ethanol wasn’t that great of an antidote. The therapeutic window is small, one must keep the Blood Alcohol Content within the target range for an extended time, the tried and true way to use ethanol as an antidote is via IV rather than oral ingestion. In addition, fomepizole is a far superior treatment for methanol poisoning. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [September 6, 2012, 8:10pm UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/6 "2012-09-06T20:10:11Z")
The whole idea of denatured alcohol is to provide something that has most of the properties (and cost) of ethanol, but so totally toxic that nobody in their right minds would drink it to get drunk. At least, that’s what I’d always heard, and it’s what Wikipedia says, so it _must_ be true! > **[Denatured alcohol](https://en.wikipedia.org/wiki/Denatured_alcohol)** > > Denatured alcohol (called methyl hydrate in Canada; methylated spirits, metho, or meths in Australia, Ireland, New Zealand, South Africa, and the United Kingdom; wood spirit; and denatured rectified spirit)\[citation needed\] is ethanol that has additives to make it poisonous, bad-tasting, foul-smelling, or nauseating to discourage its recreational consumption. It is sometimes dyed so that it can be identified visually. Pyridine and methanol, each and together, make denatured alcohol poisonous; ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [September 7, 2012, 1:44am UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/7 "2012-09-07T01:44:32Z")
I’ve heard some Australian aborigines drink methylated spirits, isn’t that methanol? ---
**Author:** ![lisiate](https://avatars.discourse-cdn.com/v4/letter/l/f05b48/32.png) [@lisiate](https://boards.straightdope.com/u/lisiate)\ **Post date:** [September 7, 2012, 1:51am UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/8 "2012-09-07T01:51:50Z")
No it’s another “mostly ethanol with enough methanol in it to make it toxic” mix. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [September 7, 2012, 2:12am UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/9 "2012-09-07T02:12:59Z")
> [@grude](#): > > If it is 90% ethanol and 10% methanol, would the methanol even matter since the body selectively metabolizes ethanol? > > Imagine a hard core alcoholic, would their body ever run out of ethanol to selectively metabolize? > > Or am I totally off track here? “Selective” is not “exclusive”. 10% is a shitload of poison to ask your body to ignore. ---
**Author:** ![sisu](https://avatars.discourse-cdn.com/v4/letter/s/df705f/32.png) [@sisu](https://boards.straightdope.com/u/sisu)\ **Post date:** [September 7, 2012, 4:07am UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/10 "2012-09-07T04:07:24Z")
> [@AaronX](#): > > I’ve heard some Australian aborigines drink methylated spirits, isn’t that methanol? Not constrained to them, you know when an alco has hit rock bottom when they start drinking metho. The preferred way was to filter it through some white bread. These blokes never lasted very long. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [September 7, 2012, 4:23am UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/11 "2012-09-07T04:23:14Z")
> [@AaronX](#): > > I’ve heard some Australian aborigines drink methylated spirits, isn’t that methanol? In Australia, it doesn’t even contain methanol. It’s absolute ethanol with trace amounts of foul tasting agents like denatonium or butanol. It tastes like crap, but it’s relatively harmless to drink. Worst symptoms are nausea and a headache. They stopped selling methylated spirits with methanol precisely because people insisted on drinking the stuff. The replacement is still called metho, but it’s fairly harmless. Commonly drunk by mixing it with “cordials”. Basically, metho and Kool-Aid. Apparently that helps mask the taste. ---
**Author:** ![Jeff\_Lichtman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jeff_lichtman/32/1531_2.png) [@Jeff\_Lichtman](https://boards.straightdope.com/u/Jeff_Lichtman)\ **Post date:** [September 7, 2012, 7:31am UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/12 "2012-09-07T07:31:34Z")
The liver produces an enzyme called “alcohol dehydrogenase” that helps metabolize alcohol. When it acts on methanol it produces formaldehyde, which is a poison. The reason that ethanol can be used to treat methanol poisoning is that the liver produces only so much of the enzyme. It’s not that the body selectively metabolizes ethanol - it’s that, with enough ethanol around, a molecule of alcohol dehydrogenase is more likely to encounter a molecule of ethanol than one of methanol. The idea is to keep enough ethanol in the system to slow down the production of formaldehyde long enough to allow the methanol and formaldehyde to be excreted in the urine before harm is done. An alcoholic drink typically contains about an ounce of alcohol, or about 29.5 ml. If 10% of this is methanol, that would be 2.95 ml per drink. According to the Wikipedia article quoted above, 10 ml of methanol is enough to cause blindness - this would be about 3 1/2 drinks. The lethal dose of 30 ml would be achieved with about 10 drinks. My guess is that, if you chugged all the drinks at once, you might excrete enough unmetabolized methanol to mitigate the damage. If you drank slowly enough to metabolize the alcohol you’d do yourself real harm, regardless of the presence of ethanol. ---
**Author:** ![Noel\_Prosequi](https://avatars.discourse-cdn.com/v4/letter/n/b19c9b/32.png) [@Noel\_Prosequi](https://boards.straightdope.com/u/Noel_Prosequi)\ **Post date:** [September 7, 2012, 8:50am UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/13 "2012-09-07T08:50:05Z")
> [@Blake](#): > > In Australia, it doesn’t even contain methanol. It’s absolute ethanol with trace amounts of foul tasting agents like denatonium or butanol. It tastes like crap, but it’s relatively harmless to drink. Worst symptoms are nausea and a headache. > > They stopped selling methylated spirits with methanol precisely because people insisted on drinking the stuff. The replacement is still called metho, but it’s fairly harmless. > > Commonly drunk by mixing it with “cordials”. Basically, metho and Kool-Aid. Apparently that helps mask the taste. I’m told that unscrupulous shopkeepers in areas where there are metho drinkers keep it in the fridge to sell chilled; that also masks the taste. ---
**Author:** ![Simple\_Linctus](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@Simple\_Linctus](https://boards.straightdope.com/u/Simple_Linctus)\ **Post date:** [September 7, 2012, 1:43pm UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/14 "2012-09-07T13:43:54Z")
Isn’t there also some special petrol they sell in Aborigine areas that is less harmfull to sniff? ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [September 7, 2012, 2:26pm UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/15 "2012-09-07T14:26:31Z")
> [@Simple\_Linctus](#): > > Isn’t there also some special petrol they sell in Aborigine areas that is less harmfull to sniff? It is called [Opal](http://en.wikipedia.org/wiki/Opal_%28fuel%29). Its main point is that it contains far fewer aromatic hydrocarbons, which both create the stupefying effect, and cause the damage. So it is both less harmful, and less desirable to sniff. ---
**Author:** ![grude](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@grude](https://boards.straightdope.com/u/grude)\ **Post date:** [September 7, 2012, 4:51pm UTC](https://boards.straightdope.com/t/would-denatured-alcohol-even-be-dangerous-to-consume/633894/16 "2012-09-07T16:51:09Z")
> [@Jeff\_Lichtman](#): > > The liver produces an enzyme called “alcohol dehydrogenase” that helps metabolize alcohol. When it acts on methanol it produces formaldehyde, which is a poison. The reason that ethanol can be used to treat methanol poisoning is that the liver produces only so much of the enzyme. It’s not that the body selectively metabolizes ethanol - it’s that, with enough ethanol around, a molecule of alcohol dehydrogenase is more likely to encounter a molecule of ethanol than one of methanol. The idea is to keep enough ethanol in the system to slow down the production of formaldehyde long enough to allow the methanol and formaldehyde to be excreted in the urine before harm is done. > > An alcoholic drink typically contains about an ounce of alcohol, or about 29.5 ml. If 10% of this is methanol, that would be 2.95 ml per drink. According to the Wikipedia article quoted above, 10 ml of methanol is enough to cause blindness - this would be about 3 1/2 drinks. The lethal dose of 30 ml would be achieved with about 10 drinks. My guess is that, if you chugged all the drinks at once, you might excrete enough unmetabolized methanol to mitigate the damage. If you drank slowly enough to metabolize the alcohol you’d do yourself real harm, regardless of the presence of ethanol. The answer I was looking for, thank you.