Could you use the moonshine test on hand sanitizer? If it burns blue then you know it’s ethanol and if it burns yellow it’s methanol? I’m not familiar with the other ingredients in hand sanitizer so I don’t know if this would work (so don’t try it at home!) I’m only asking out of curiosity.
You're more likely to detect metallic or other organic contaminants which are likely (moisturizers etc) in sanitizers of both sorts. Even the effect shown above only shows up in an oxygen restricted environment (like the bucket above) due to the extra O2 the ethanol carbon needs to burn clean. You won't see that if you put it in a spoon where there's plenty of air. Any other carbon/sodium compounds are likely to show up and orange/red.
Most hand sanitizers seem to include glycerin, which will burn with a yellow flame as I remember. It's worth looking more into this type of testing though, I don't know if the concentrations of glycerin would be enough to effect the flame color.
I saw a paper indicating that ethanol and isopropanol are not readily absorbed through the skin, but can enter as fumes -- enough to show up on an (overly sensitive) drug screen.
I would expect methanol might be similar, although it is quite a bit smaller. However, I wasn't able to find any information on this. Any sources?
From [1]: "In human metabolism of methanol, given its physical and chemical properties, high skin absorption is expected. Methanol penetration is predicted at 2.0 mg/cm2/h (logP = −0.77). Skin absorption of methanol vapor is another primary exposure route in terms of respiratory exposure."
I had a hard time finding dermal exposure thresholds for adverse effects. Oral intakes associated with severe acute effects were easier to find and could be used to estimate the effects of dermal intake. The smallest systemic oral intake threshold I saw was 3–11 g: "An oral intake of 3.16–11.85 g/person of pure methanol could cause blindness."
From those values, I think you're probably right; at least, death or blindness from dermal exposure to methanol seems unlikely. But the thresholds for less severe symptoms and the relevant intake thresholds for symptoms from chronic exposure are unclear to me.
Hand surface area is often given as 1% of body surface area (1.5-2 m^2), i.e. 150-200 cm^2, unclear if one or both hands but I assume one. I've also found claims of 400 cm^2 for one hand.
Methanol penetration is predicted at 2.0 mg/cm2/h" would imply that assuming two hands of 800 cm^2 total, exposed to methanol "hand sanitizer" for 5 minutes, would absorb 133 mg of methanol.
I think the skin absorption issue is a red herring and the real issue is that people keep drinking it.
As a Boy Scout in the 90s we used methanol stoves (Trangia) and lanterns, in the UK it’s untaxed alcohol.
Spills were common, as was pouring it in your hand or boot, igniting it and running around in the dark. I’m sure we came into contact with way more than you’d use as hand sanitizer—-and I never heard of anyone with ill effects.
Yeah, this confirms my belief that infrequent dermal exposure to methanol is not a particularly pressing health concern. It sounds like very little gets through the skin, and the main concerns are skin irritation, which you can get with ethanol anyhow.
I'd be fine using a 90% ethanol 10% methanol hand sanitizer the way I currently use it -- spraying my hands and rubbing them maybe 4 times per day either outdoors or in a well ventilated house, and not horking the fumes.
It looks like every single example they found with methanol contamination is imported from Mexico. I wonder if that's just because they only started there or if it's not a problem with imports from other regulatory domains.
If I recall correctly, most of the moonshine blindness was not due to improper distillation technique (i.e. not cutting your distillation head), but rather that methanol was often used to dilute ethyl alcohol.
Most fermented alcohol doesn't contain a significant amount of methanol to begin with, fermented fruit being the exception. After distilling you can usually drink the heads with no risk of methanol poisoning. You'll still get a nasty hangover from aldehydes and higher alcohols if you do, but it won't kill you.
The majority of methanol poisoning cases are where illegal spirits have been deliberately adulterated with industrial methanol (most likely with denatured alcohol, which is still 90%+ ethanol) to increase profits.
You're just being stupid. Denaturing agents are used to make the product unpalatable. They may be mildly toxic, but they are so disgusting that users typically don't absorb much of it.
Methanol, on the other hand, is not just more toxic but also reportedly tastes better than than ethanol. As such it encourages people to drink it. Using it to punish illicit alcohol drinkers is just plain evil.
Well, this kinda answers the question I had, which was whether you could use denatured alcohol to sanitize things. Because, when the crisis started and you couldn't get isopropanol, you could still get denatured alcohol by the gallon. But I assumed it had this hazard and didn't buy any.
Now that you mention it, I wonder if maybe these hand sanitizers have methanol contamination because the manufacturer saw that denatured alcohol was cheap/available and tried to swap out their usual source to make a quick buck?
It depends upon exactly how the alcohol has been denatured. I'm of the understanding there's a couple ways: lacing with methanol to make it poisonous, or lacing with bittering agents powerful enough to make even the most desperate alcoholic spit the stuff out reflexively. But, not knowing which method is in use, probably better to avoid using denatured alcohol for sanitation purposes.
True. The cans of denatured alcohol at Home Depot said methanol (or methylated spirits, whatever). But that's a sample size of one. They were also labeled "alcohol fuel" or something like that.
I'm not sure what legitimate purpose ethanol serves at a home improvement store. To improve my home, ethanol has to be drinkable. ;-)
>I'm not sure what legitimate purpose ethanol serves at a home improvement store.
because how toxic alcohols other than ethanol, to humans and pets, i never bring other stuff to home. For cleaning/sanitizing purposes there is currently a bottle of Smirnoff among cleaning supplies under the kitchen sink. Yes, i'm Russian and say 25 years ago back there i'd consider such usage of good vodka a capital crime :)
Not being familiar with these brands at all, I wonder if they were created during the pandemic or existed before; and if the latter, did they always contain methanol and were now just discovered, or recently started to be adulterated due to ethanol shortages?
I had no idea that all those stereotypes about moonshine turning people blind and/or crazy were real - I guess methanol alcohol was a common enough contaminant in bootleg alcohol during prohibition. And wherever they make moonshine these days, though I imagine even backwoods people are wiser these days.
Distillation is a way for farmers to transform crops into a denser form with arbitrary shelf life. This means that if they think local spot markets are offering a raw deal, they have the options of both temporal and spatial arbitrage.
In my country, people with stills on trailers often come around to villages to help the farmers with excess crops, and home distillation is legal. I haven't heard of problems with CH₃OH.
Even in russia distillation has been legal for all of this century. I would not be surprised if a fair amount of the booze mentioned in "Выпил С2H5OH / Сел на «Ниву» Ростсельмаш" was homemade. (who needs a fancy https://en.wikipedia.org/wiki/Local_currency when one can express appreciation for favours in bottles?)
For that matter, in china, 白酒 is discouraged but legal.
Anyone know what the north korean line may be? If they're a repressive state on the order of iran or the soviet union, they might ban home distillation.
Toxicity for methanol also comes through skin absorption and inhalation of vapors. The effect you're concerned about there is what happens when your body breaks down the molecule - formaldehyde is an intermediate metabolite and is pretty toxic.
