The Performance of Alcohol Fuels for Backpacking StovesPart One: Three Straight Alcohols and Alcohol Blends

[Addie Bedford]

Companion forum thread to:

The Performance of Alcohol Fuels for Backpacking Stoves
Part One: Three Straight Alcohols and Alcohol Blends

[Mark Hurd]

>FYI Alcohol/water mixes and flames are covered in part two of this series which will be published soon.<

Hi, Tony,

I am anxiously awaiting the next installment.

-Mark

[Bill Cooper]

I've used alcohol stoves for many years, from Trangias to cottage industry stoves to homemade ones. But what's always bothered me is the fuel itself. Denatured alcohol (at least in California) gives me headaches and bothers my breathing, regardless of whether the fuel is freshly poured or burning. I've tried many brands of denatured alcohol from marine stores and hardware stores without satisfaction. The alternative, high proof ethanol like Everclear, is illegal in California.

But Roger's and Tony's article got me thinking about pure methanol, re Tinny's comments. Yes, it's toxic if ingested (so is white gasoline) but if it burns cleanly… So I went to an auto parts store and got some yellow Heet. Surprise! Methanol has little discernable smell whether poured fresh or while burning. No headaches, no nausea – and no corruption of the wilderness experience with noxious odors. I will still stand back from a stove while it's burning, but I won't feel the need to walk in circles to avoid the vapors.

I did some tests using a Caldera Cone, 450ml Snow Peak Titanium cup with lid, and an open flame burner (tea candle tin mounted at approximately the same height as the orifice of the Caldera stove (the tea candle tin makes it easy to recover the unburned fuel for measurement)). My results tracked those in the article: the two fuels (denatured alcohol and methanol) had about the same heating rates but methanol required about 25% more mass.

Hey, I'll gladly carry the extra fuel to avoid the fumes from additives – if that's what I'm avoiding. Any bio/chemists out there?

[Roger Caffin]

Hi Mark

> I am anxiously awaiting the next installment.

not long …

Cheers

[Roger Caffin]

Hi Bill

> Denatured alcohol (at least in California) gives me headaches and bothers my breathing,
Well, check the list of possible additives (or should we say 'contaminants'?) in the article! Tinny has had similar experiences, with choking fumes from 'denatured alcohol'.

I suggest that the concept of total market deregulation may have some draw-backs here. Like your health.

I am forced to agree with you that if all other sources of denatured ethanol are so toxic in California, you might be better off with methanol/HEET. I don't like it, because it is toxic to humans when ingested, but the alternatives you have seem worse.

Cheers

[Ryan Linn]

I haven't tried too many kinds of denatured alcohol (mostly just SLX and Sunnyside), but the one time I used Sunnyside it burned wicked sooty and blackened my pot and everything around. I only tried it that once, since I didn't have any soot while using SLX.

Might the stove have something to do with how well the stuff burns, or could there be variations in individual batches of the alcohol? Sunnyside seems a lot easier to find in my area than SLX, so it would be nice if it burned clean.

Side note: how easy is it to find yellow HEET in the summer?

[Greg Mihalik]

Ryan,
I'm surprised at your Sunnyside results. I've use Sunnyside Denatured Alcholol for years without problems in Trangias and recently in Caldera Cones.

I'm curious about your stoves and setups as I want to avoid those problems for myself. Lack of oxygen seems the likely culprit – a windscreen that is to tight?

I note that you are using a wicked stove and from what I have seen on Tinny's site there is always a little bit of black magic there. Have you had the same results with basic non-wicked burns?

I also see that KleenStrip S-L-X is nearly a 50/50 mix of ethanol and methynol, plus 5% methyl isobutyl ketone. I don't know how that affects the burn, but it will reduce your heat output.

[Barry P]

“Side note: how easy is it to find yellow HEET in the summer?”

Even though it’s a ‘winter’ thing, it seems pretty easy to find it all year long. I see them all the time. One of these stores will always have it: http://www.goldeagle.com/brands/heet/where_to_buy.aspx
I buy a year’s stash in March when most HEET sales happen.

There’s a Walmart generic version of yellow-bottled HEET and if you’re lucky enough to find it, not only is performance equal, it will save you a lot of money.

And as a non-backpacking side note: another nice thing about HEET is it can be stored forever; it doesn’t break down. So it makes a good addition to 72-hour emergency kits. Thus, if you find a good deal, stock up.

-Barry

[Walter Carrington]

According to the MSDS I've seen methanol is toxic by inhalation or absorption through the skin. I don't think inhalation is going to be a problem — just don't spill your fuel bottle inside a small tight tent.

Absorbing methanol through the skin is hard to figure how bad it is. Spill 8 oz on your clothes and you'll inhale and absorb some; I don't know how much. It's not going to kill you (immediately) but what about longer term damage???

My guess is that skin absorption and inhalation are not harmful in the amounts likely in stove use, even over the 5 months of an AT thruhike. I would be a lot happier if someone who KNEW could enlighten us. Any toxicologists on BPL?

[Ryan Linn]

Haha. Greg, that's "wicked" as in New England Speak for "very", not a stove with a wick :)

I did only try sunnyside that once, so maybe I'll try it again. I was using a mark jurey penny stove with a loose windscreen. I've since switched to a caldera cone. I think I'll give it another try sometime this summer.

[Bill Cooper]

Though denatured alcohol bothers me (see my post above), I've found Sunnyside the least objectionable of the ones I've used. Burns clean and the odor is not as strong as others I've tried.

[Lynn Tramper]

"According to the MSDS I've seen methanol is toxic by inhalation or absorption through the skin."

So is ethanol!

[Greg Mihalik]

…and so is H20…

[Tad Englund]

Tony and Roger, great work, you answered my question about which is better, that I’ve had for years. I’ve used both “real” methanol, not “Heet” and STK denatured acohol and have been wondering which is better. Now I know.

I have 55 gals of Methanol that I use to make Bio-Diesel, so basically I have a life time supply of it. Mine is about as pure as you can get it. Better then the “Heet” brand. I pay about $2 to $4 a gallon for it depending on the oil market. For me it is the best priced stuff I can get for my stoves. After seeing your information about Denatured Acohol I am inclined to stop using it, even though I use STX which is pretty clean.
I find the ultra high cost of Everclear far outweighs its weight benefit. For me, I can use Methanol and it costs me nothing (again I buy it by the 55 gal drum). I’ll take the weight penalty.

Roger I don't understand the worry about ingesting methanol. It never occurred to me to drink it. I also would never think of drinking Everclear either.

[Roger Caffin]

> KleenStrip S-L-X is nearly a 50/50 mix of ethanol and methynol, plus 5% methyl isobutyl ketone.

I am not sure I like the MIK bit. The MSDS says:

Routes of Entry: Dermal contact. Eye contact. Inhalation. Ingestion.
Toxicity to Animals:
WARNING: THE LC50 VALUES HEREUNDER ARE ESTIMATED ON THE BASIS OF A 4-HOUR EXPOSURE.
Acute oral toxicity (LD50): 1600 mg/kg [Guinea pig].
Acute dermal toxicity (LD50): 20001 mg/kg [Rabbit].
Acute toxicity of the vapor (LC50): 8000 ppm 4 hour(s) [Rat].
Chronic Effects on Humans: The substance is toxic to lungs, the nervous system, mucous membranes.
Other Toxic Effects on Humans:
Very hazardous in case of ingestion, of inhalation.
Hazardous in case of skin contact (irritant, permeator).

Cheers

[Bill Cooper]

Although I'm now attracted to methanol as a stove fuel, I might not use it when camping with children. Adults would probably observe poison warnings (I label all my fuel bottles boldly) but a child might not. Since methanol is highly toxic when ingested, even a very small amount might be lethal, especially to a child.

I think it's right the authors and BPL continue to note the cautions on methanol and its toxicity when ingested. It's best not to discount common wisdom without understanding where that wisdom came from.

BTW, thanks to Roger and Tony for all the work put into the article, and to Roger for the entire series of articles on stove properties.

[Tony Beasley]

Please note the treatment for Methanol poisoning is drink some Ethanol.

A good document to read on Methanol

http://en.wikipedia.org/wiki/Methanol

Tony

[Walter Carrington]

DISCLAIMER: I am not an industrial hygenist or toxicologist. I've sent an email to US OSHA to ask what they think of using methanol or denatured alcohol in camping stoves.

I've done a bit more research on inhalation toxicity for alcohol fuels. My tentative conclusion is that with decent ventilation inhalation of methanol is probably not a problem when used outside (not in a tent). In a tent, it's probably not a problem unless you spill it. If you spill some inside a tent, stay out of the tent until it's thoroughly aired out (20 minutes to an hour?) Of course, carbon monoxide can be a serious problem if you cook in a tent.

OSHA = US Federal Occupational Safety and Health Agency
PEL = Permissible Exposure Limits based on an 8 hour average.

Methanol OSHA PEL†: TWA 200 ppm (260 mg/m3)
http://www.cdc.gov/niosh/npg/npgd0397.html
Ethanol OSHA PEL: TWA 1000 ppm (1900 mg/m3)
http://www.cdc.gov/niosh/npg/npgd0262.html

By comparison,
Carbon Monoxide:OSHA PEL†: TWA 50 ppm (55 mg/m3)
http://www.cdc.gov/niosh/npg/npgd0105.html

So methanol inhalation is significantly less toxic than CO by about a factor of 5, and ethanol is less toxic than methanol by a factor of 5.

Spilling 100 g of methanol in a tight tent will certainly exceed this PEL level of 260 mg/m^3. If we assume it all evaporates immediately in a tent of 3 m^3 volume:
Initial concentration will be:
33,000 mg/m^3. Assume the tent with door/windows open has 6 air changes per hour, and not really solving the differential equation, roughly:
after 10 minutes — 16,000 mg/m^3
after 20 minutes — 8000 mg/m^3
after 30 minutes — 4000 mg/m^3
after 40 minutes — 2000 mg/m^3
after 50 minutes — 1000 mg/m^3
after 60 minutes — 500 mg/m^3
after 70 minutes — 250 mg/m^3

If you can mop up most of it before it evaporates, you can cut this time down considerably.

[Mark Bishop]

Last year I bought a can of denatured alcohol from REI with a brand name called 'Crown' – there was no content information on the can that I could understand. So I did a search on the Crown website and found the MSDS stating it has the following ingredients:
65-75% METHANOL (67-56-1)[200-659-6],
20-30% ETHANOL (64-17-5)[200-578-6],
< 10% ISOPROPANOL (67-63-0)[200-661-7],
< 10% METHYL ISOBUTYL KETONE (108-10-1)[203-550-1]

Seems like the SLX brand, that is available from Home Depot, might be a bit safer.

[Bill Cooper]

Tony wrote:

>A good document to read on Methanol
>http://en.wikipedia.org/wiki/Methanol

Seems methanol is widely used as a fuel in motor sports. I haven't seen a lot of obituaries about racers and pit crews dying from its effects.

Nonetheless, the wikipedia article states the ingestion of only 10 ml is enough to cause blindness. That's hardly a sip full.

Not to harp, but, I'd really be leery about having methanol around small children on a camping trip (said by someone who will take it on his own hikes). Methanol is something you'd keep locked away from children in your house, like ant poison. Camping with kids can be chaotic enough without keeping track of small plastic bottles (oh, so attractive to little ones) filled with poisonous fuel left near the stove.

If I were camping with small children I'd go with a canister stove – forget alcohol and the rest. Wait until they get older. I don't trust anyone, including myself, to be perfectly attentive. One of the first rules of safety is to guard against mistakes.

Of course we're talking about two different paradigms: the serious hiker vs. "let's take the kids for an outing". Perhaps I dwell on this to disabuse myself of carrying over behaviors from one to the other without examining certain assumptions of behavior and risk.

[Walter Carrington]

Bill, "If I were camping with small children I'd go with a canister stove". I agree. Even pure ethanol could be dangerous for small children.

[Brad Groves]

Tony and Roger, just wanted to say thanks for the effort, time and insight. Great to have that data at hand!

[James Schipper]

Has anyone noticed a difference in the performance of ethanol and methanol in cold weather. Ethanol is more energy dense, but methanol has a lower evaporation point and may be easier to get started at the low end of usable temperatures for alcohol stoves. This seems like a situation where a mix of methanol and ethanol might be best, analagous to mixing isobutane and propane in a canister stove.

Any thoughts?

[Greg Mihalik]

Alcohol stoves in cold weather are usually primed to get things going. Once that is accomplished (30 seconds?), IMHO, I don't think vapor pressure makes much difference. In a Caldera Cone – or any tight windscreen environment – things are going to be plenty warm.

[Roger Caffin]

As Greg said.

Cheers

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