Alcohol stove residue – how toxic is it?

[Marko Botsaris]

I guess this post ultimately devolves a gear-use question, so I'm posting it in the gear forum. Toss up with the general forum. Hope this is an OK place.

I'm a long-time canister user who recently started messing around with Alcohol stoves. I'm trying to put together a compact solution and I've seen many pictures here and in other places showing the way people pack. Lots of people put their cat stoves, wind screens, sidewinder cones, etc. in what would seem like the obvious place – *inside* the pot. Short of using Everclear, my understanding pretty much all solutions for fuel range from mildly nasty to dangerously toxic. Seems like most/all of the latter can leave some residue as well. If this is just some carbon residue from incomplete combustion then there would not be a problem. My concern is for the extra added toxins in these fuels.

So my concern/question is – what do people feel about this? Would I be wise to contain the stove parts in a plastic bag when stored inside my pot? Do people always do an pre-rinse before boiling their water? Do you just wing it?

Let me know what you do, and I'll try to figure out from your answers which ones of you have already killed a ton of brain cell with stove toxins ;-)

[Ben C]

I have never seen anyone do much of anything other than toss it in the pot. Put it in a plastic bag if you're concerned.

[Marko Botsaris]

So does anyone have an issue/worry about putting objects exposed (potentially) to pretty nasty stuff like HEET in direct contact with your spoon, inside of pot, and so on? Ingesting toxins, even in small quantities, is usually many orders of magnitude worse than, say, rubbing them on your skin. There would potentially be un-combusted residue in the stove itself as well as combustion residue on the stove, windscreen, etc.

FYI I'm not really worried about volatile stuff like methanol. Are all the additives in such mixture volatile? I guess leaving some drops of different fuels to evaporate on a clean surface might give a clue, at least for the un-combusted fuel residue.

[Daniel Fish]

…

[Richard Cullip]

I never gave it a thought. I just wrap my windscreen around my alcohol bottle, slip them into my Fancee Feest stove (from ZelphStove) and put them into my 900ml Ti pot. Never worried about any burned or unburned residual sticking to my pot and poisoning me. I think the danger level is remarkably small and it's a risk I'm willing to take.

[Dale Wambaugh]

Nahhh. Swish a little water in the pot if you have concerns, but any residual fuel would evaporate fast. You're in far more danger breathing fumes on the highway on the way to the trailhead.

[Marko Botsaris]

Um, yeah. I was just reading about some of the additives and I think I'm going with the plastic bag for everything inside. Remember that there are always trace additives, some secret and/or proprietary. The ethanol-based ones like denatured alcohol deliberately have toxins added to make sure people don't drink it as an alternative to alcohol. Didn't work so well for Sterno in days gone by. I guess never underestimate the motivation of an addict to get a fix, even if it kills them.

Anyway HEET is antifreeze! Isn't antifreeze supposed to be one of the most common ways to off yourself with a simple everyday product?

Isopropyl alcohol, btw, such as the stuff you buy in a drug store in fact leaves a ton of residue. The fact that it is a bit mucky/sticky to the touch makes me think it likely may contain more than pure carbon residue. Also combustion *creates* toxins (including carcinogens) so guessing probably not the way to go here. Strictly speaking %99 iso would be %1 potential mucky-muck (though it is mostly added water). So it might be out of sight out of mind in this form, but not necessarily good for ya.

As I mentioned, I'm worried about the non-volatile residue. I'm willing to give the stuff that will evaporate like methanol a pass. If you have used these stoves you know that many/most fuels seem to leave a fixed sticky residue. There are even several threads here about how to (cosmetically) clean it off the bottom of your pot.

I have been using a version of de-natured marketed as Marine Stove Fuel which is supposed to be cleaner. It doesn't seem to leave a visible residue. However…. !

Not breathing anything bad is not my concern. My worry is injecting stuff directly into my digestive tract.

Oh, and I AM worried about the fumes I breathe on the way to the trailhead! But I'm not sucking on a tailpipe either :-)

[Marko Botsaris]

"I never gave it a thought. I just wrap my windscreen around my alcohol bottle, slip them into my Fancee Feest stove (from ZelphStove) and put them into my 900ml Ti pot."

Richard, as far as this goes I'm pretty sure you are out on the tails of the bell curve there. As far as I can determine conventional thought on this issue is that (1) always bag your bottle in case there is a small leak that might get on stuff, and (2) never put the bagged bottle inside your pot.

I could be very wrong about this though. Seem like most of what I have read emphasizes these two. Doesn't mean it is right though.

I know that fuel can eat your clothes and (1) may just come (especially in this community) from a desire to protect expensive gear. As in "who cares if it gets in my food, just keep it the hell away from my Patagonia!" LOL

[Harald Hope]

Mark, your question is smart, and you are totally right, there seems to be a sort of strange tendency, or disconnect, or misplaced cavalier attitude, among far too many bpl backpackers to disregard toxins or to discount them, so your posting is a welcome one. For example, cooking in a bpa lined beer can… shudder. Certain people here I do understand why they tend to do this, it's the simple old formula of not questioning too much or rigorously the source of your income…

Of course these things are toxic, reading the msds for any fuel shows all kinds of nasties, and they don't really even have to be honest about what they actually say is in there, at least not judging from the ones I've read where the proportions listed are mathematically impossible to achieve, ie, they don't add up to 100% no matter how you combine their numbers. And certainly most people commenting about the stuff being safe have probably exactly zero idea of what happens to say ketones when the methanol/ethanol evaporates, or if trace amounts routinely enter your body, I certainly don't know, but I'm sure it's not good. And remember, the word 'denatured' is just a polite term for 'toxically poisonous so you cannot use it to drink'.

I've been starting to wonder the same thing recently as you, primarily because I've been doing so much stove testing, where you really start to notice the toxicity of the substances (please people, do NOT test these things indoors), I think the thing that triggered my increased awareness was talking to a real chemistry professor, who noted that in the labs, they are not allowed to even open methanol unless it's directly under a ventilator. That's open, not burn. SLX is half methanol, give or take some unknown percent.

I don't think putting the stove in a plastic bag is foolish, but I do suspect that rinsing the pot out with water should be enough in general re dilution and removal of toxins, as suggested above. And the question of leaks of the smaller fuel bottles, if stored in the pot, is also a very good one, that I think I'm going to reconsider, while I like having it in there, I don't like ingesting toxins when my goal is actually to be in nature, some parts of home really are best left at home.

Nice to see someone thinking about stuff and questioning some basic bad practices that we tend to not think about just because they might be 'convenient', or let you get on the trail 13 seconds sooner, or whatever.

Also re burning the fuel, unless you are achieving 100% efficiency, ie, burning fully all the alcohol, you are almost certainly getting either non combusted or partially combusted vapors, and the partially combusted ones do some interesting things in terms of what chemicals they turn into on their way to the full combustion by products you see listed on the chemical pages on say wikipedia, you know, co2, co, water, etc, but that's only in a theoretical perfect combustion, that's not what the actual exhaust vapor contains, as one interesting discussion of this I think on zenstoves noted, actually nobody knows fully what chemicals are produced in the flames until it's fully combusted, it's a range, interesting reading by the way.

Pure ethanol is the only alcohol fuel where you can totally ignore all these issues, it's safe, except for drinking too much, of course.

[Dan Yeruski]

Anyway HEET is antifreeze! Isn't antifreeze supposed to be one of the most common ways to off yourself with a simple everyday product?

---

HEET is used in gas tanks to absorb moisture. Moisture in gas tanks condenses in low areas of gas lines. In freezing temperatures that water will freeze. Remove the moisture, prevent gasline freeze.

[Harald Hope]

yellow heet is supposed to be all methanol, which is very poisonous, and I would assume that if they feel like it, they put in whatever other chemicals they feel might improve the function of heet, which is NOT a convenient to find stove fuel. So heet can safely be assumed to be fully poisonous, with unknown other toxins possibly added without you knowing it.

I believe heet is designed to be gas line antifreeze, if I remember right, ie, it's not regular antifreeze, which is a consistently popular way to kill off neighborhood cats. Antifreeze is different, because it has to function at both very high engine temps and frozen temps, so I doubt it has alcohol in it.

I assume what heet does is bond the water molecules sort of to the alcohol ones, and since alcohol, as we all know from the bottles of stoly we keep in our freezers, does not freeze until it gets very cold, that keeps the water in the gas from freezing. Or something like that.

[Ike Jutkowitz]

I use everclear for this reason (and cause I like to have a splash of it in my evening drink)

[Ian]

I keep my Esbit and any residue away from any surfaces that will come in contact with my food with a sandwich bag as well. It doesn't register on my scale and I appreciate the peace of mind.

[Harald Hope]

I'd do the same, it's not a big expense for a week trip, 8oz for 2 meals a day, only we can only get 75% everclear here I guess.

I wish we could buy a real denatured alcohol, with pure ingredients, ie, 90% ethanol, 5%methanol, and nothing else. The rest being water of course, since I believe 95% or so is the highest you can practically get alcohols, the rest is water. Then at least you'd know what you were burning and what it does on combustion, I'd say it's a safe bet that nobody here knows what the ketones and other additives, ethanols, and methanols actually do when they burn together, incompletely, say when we burn slx or klean strip green.

I'm going to start using a little bag to put the stove in, that thought had been bouncing around in my head, and this thoughtful post OP makes it a sensible and simple solution, where no real reason can be cited beyond simple stubborness to not do it.

[Marko Botsaris]

I know I was beginning to sound a little like one of … those people…LOL I actually pretty laid back about stuff like this, and my scientific background sometimes makes me scoff at people with over-elaborate issues about stuff in the environment – particularly the conspiratorial ones with no actual evidence.

Possibly my paranoia on this issue comes from back when I was doing biophysics research. One of my labs had exactly the kind of hood you described devoted to anything that involved toxic and/or noxious stuff. OSHA regulation required all of this stuff not only to be manipulated, but also stored at all times, in the hood. Leaving aside the fact that I had a small bottle of hydrofluroric acid (eats through metal, glass & flesh like Ridley Scott's alien blood, and if gotten into the blood stream in trace quantities will leach the Calcium right out of your bones) there were a lot of other more prosaic things in there like Methanol and Acetone. Any food or eating of any kind was totally prohibited in the lab! Anyway, this type of thing tend to remind you that only a small amount of certain things can be toxic, especially cumulatively, and to mistrust the idea that if I can't see it and I don't throw up 20 second after exposure it isn't doing any damage.

Anyway, baggies will be light and will reassure me.

[Ike Jutkowitz]

We can only get the 75% stuff here too. Luckily, one of my residents has a girlfriend in Indiana. Once every year or two I have him bring me back a jug of the 95% stuff. Before that, I was using the kleenstrip green denatured alcohol which is about 90% ethanol.

[Marko Botsaris]

"yellow heet is supposed to be all methanol"

The fact that it is yellow means it is not "pure" in any sense that is important for toxicity since I'm pretty sure high purity methanol is white – I have worked with laboratory grade methanol many times. By "pure" on the label it probably mean the the active combusting ingredient is methanol and not some mix of fuels. But the yellow color, for example, means something was added – possibly just as a marketing tool as in "our stuff is yellow, and therefore unique and better". Anyway, the vast majority of the additives that are added don't necessarily have a color to tell you they are there, or even an obvious residue. This doesn't mean they are bad, but it does mean that they are not being used "as intended" if ever exposed directly in this way to your digestive tract.

You rightly point out that methanol itself is toxic, but as I said above, since it is a tiny volatile molecule it will quickly float away when exposed to air, so I'll give it a pass. As long as you don't make a habit of sniffing it the bottle, or using it in unventilated areas I think you will be safe on that account. What I mostly worry about is the other stuff added to the base fuel or created by combustion from the mixture that might get left behind when the methanol, ethanol or whatever has fully evaporated or combusted, and then gets into your food where it can potentially do WAY more damage than anything you touch or breathe.

[Marko Botsaris]

"keep my Esbit and any residue away from any surfaces that will come in contact with my food with a sandwich bag as well. It doesn't register on my scale and I appreciate the peace of mind."

Ian, yeah, I think Esbit and Esbit residue (or especially from the Esbit wannabes) is possibly the mustard gas of the potential stove residues. I love the idea of Esbit tabs, but I eventually nixed the idea of using them with anything other than a pot that I wasn't willing to throw away, and certainly would never allow it to touch any surface that would come in contact with anything I would eat.

Even so (though Esbit is not as bad as some of the other tabs) people typically put the pot in a bag so it will not (a) smell up their gear, and (b) soil their gear. But inside the bag the bottom of the pot soils the inside of the bag, and then things get bounced around and otherwise reused, and eventually some of it get on the lip of the pot and possibly into you. Same can be said for other types of residue, so playing devils advocate, still seems like an issue.

[Ben C]

The bottle is yellow, not the fuel. People call it yellow heat to distinguish it from the heet in the red bottle

[Ben C]

I never see any residue in my stove after burning. You might see a light char on the pot but that's it

[Ian]

I hear you but I keep my pot in a cozy so it doesn't contaminate my other gear.

[Marko Botsaris]

Ok, fair enough. I think I saw it listed as having proprietary ingredients in it, so same issue without the yellow tinge.

I was looking for Everclear this week in my hoity-toity bay-area grocery story spirits section, and of course it was not there. I will have to checkout the local seedy-looking liquor store. At least it would be a true multi-function item – fuel, sterilization of wounds, and, um…medicinal uses on a cold night.

"I hear you but I keep my pot in a cozy so it doesn't contaminate my other gear."

Yeah, if one follows everything to its extreme paranoiac conclusion, then you would be putting your baggies inside baggies ad infinitum. LOL Your method sound good enough for my level of paranoia though.

[Walter Carrington]

From the MSDS Yellow Heet is 99% methanol and 1% proprietary ingredients. The residue from methanol should be safe; the proprietary ingredients, who knows?
I've found rubbing alcohol in a local pharmacy that is 90 or 95% ethanol that might be safer, if you can find it ( http://www.healthmart.com/StoreLocator/Store-locator.aspx ).

[Harald Hope]

Mark, I googled it, and, the internet never being wrong, california doesn't allow greater alcohol content than 151 proof, 75%, so the everclear even if you can find it here, will be 75%.

"The alcoholic beverage called Everclear is illegal to sell in 14 states. These states are California, Florida, Maine, Massachusetts, Hawaii, Iowa, Michigan, New York, Nevada, Ohio, Washington, North Carolina, New Hampshire and Minnesota. Although it is legal in Virginia, it is not sold there due to the fact that the state liquor stores cannot sell any type of a grain alcohol that lacks flavor or color.The reason it is illegal is because it contains such a high percentage of alcohol. Everclear is 190 proof and is 95.6 percent ethanol alcohol and 4.4 percent water. This combination makes for an extremely powerful combination.Everclear has been listed in the Guinness World Book of Records as the most alcoholic drink. Guinness listed it in 1979 and has since banned any alcohol entries in their publications.There is a 151 proof of Everclear that is legally sold in California, Iowa, Florida, Michigan, Minnesota, North Dakota, Washington and West Virginia." source

Also, like you, the reason I started reconsidering this was because of the source of my information, a practicing scientist with decades of material safety experience, not one of 'those' people.

I can tell you however that, even if I burn outside, after doing a week or so of stove testing, I can definitely feel that there is something wrong in my lungs, there's no doubt about it. It will clear but it's definitely there. Not such an issue outside, in the true outdoors, where you are not peering down into the stove flames to see how the burn patters are, and just lighting it and waiting for it to finish. I do believe however that getting methanol on your skin is probably not a good idea.

Oregon, however, does have everclear legal, but the downside they have the state liquor stores only for hard alcohol, or they did last I was there, and they aren't that cheap. I wish we could just buy simple denatured ethanol, it's not like it's hard to find ethanol wholesale, it's cheap, I think it's about 3 a gallon give or take for the stuff they mix in gasoline.

After looking at quite a few msds for various products, I started to realize that they have very little to do with reality, more than one I checked had impossible proportions of the ingredients listed, ie, they did not add up to 100%, no matter what you did. That made me realize that a msds should never be considered as true, but rather a formality that the company produces so they can say they have one, but you shouldn't trust them to 1% accuracy, maybe 5, maybe, 10%, hard to know because I don't think there is any government regulatory agency that actually verifies that they are true, and true consistently, ie, batch to batch. This would particularly be true if they import ingredients from china, where things like putting toxins in baby food and toothpaste are relatively recent proven events, so if they can find a cheaper thing than whatever is supposed to be in it, that's what they will use.

[Harald Hope]

I'd have to see if they ship to california, but this company has organic alcohol, not interesting so much for the organic as the bulk prices for straight ethanol, 90%, $225 for 5 gallons. Not sure if they can ship to california. That's if my math is right, only 5.60 a pint, and a pint is 2 weeks or so of cooking.

I'm sure you can find lower prices for non organic, I think this stuff for making infusions etc for organic food stuff.

[Author]

Posts