TRIOXANE

James, I suspect I have the same stuff. My brother found it at a surplus store and got me some.

According to the oh-so reliable wikipedia (yes, sarcasm), 1-3-5 Trioxane mixed with Hexamine results in solid fuel tablets that go by a variety of names including “heat tablet” and “Esbit”.

To be honest, the warnings on the package are a little scary to me:
1. Take precautions to avoid contamination of food by loose product.
2. Cleans hands after handling
3. Seek immediate medical attention if ingested.
4. Do not breath fumes.

If I were to take a wild guess I’d say it is probably the same or similar to and Esbit tablet.

Does anyone else around here know for sure? I’m curious to find out.

The MSDS for Esbit states it is made of 80-100% Methenamine/Hexamine. Everything you ever wanted to know about ESBIT safety thanks to the MSDS (Materials Safety Data Sheet): http://zenstoves.net/MSDS/MSDSEsbit.pdf

Here's the MSDS for trioxane:
http://www.sciencelab.com/xMSDS-s_Trioxane-9925338

Some on the chemistry of both:

http://zenstoves.net/SolidFuelBurner.htm#Hexamethylenetetramine

http://zenstoves.net/SolidFuelBurner.htm#Trioxane

Backpacking has a good comparison of the two from a functional perspective:

http://www.backpacking.net/contributions/showthreaded.php?Cat=&Number=173&page=&view=&sb=5&o=

Trioxane is a low-powered, unreliable, unsafe fuel, best avoided if possible. The trioxane on the market includes old Vietnam era production and some later production to satisfy the "military surplus" market. I believe the military stopped using it several years ago.

Trioxane is polymerized formaldehyde. Formaldehyde is an alcohol that is used for enbalming fluid (formalin) when disolved in water. It is also seriously not good for you for a variety of reasons including: Formaldehyde fumes turn to formalin in your nasal passages, eyes and lungs. Formalin is a powerful drying agent and those organs need to be kept wet, so exposure can cause real damage.

Bottom line: trioxane has a lower heat output than Esbit (hexamine), emits formaldehyde when burned, and is toxic until burned. Formaldehyde is also a combustion product of both Esbit and alcohol, but they generally emit less. If the foil packs of trioxane tablets are breached, the formaldehyde sublimates – evaporates – because the polymer bonds are weak. Denatured alcohol is also toxic (skin contact, ingestion) because of the inclusion of methyl alcohol. Hexamine is considered non toxic, but I wouldn't eat it.

Thanks for all the great resources! I now have enough information to begin making some informed decisions.

Thank you. I guess it pays to look a gift horse in the mouth, every once in a while.

I'm confused how esbit is labelled as non-toxic, hexamine while not confirmed it is labelled as a suspected immuno, respiratory, and skin toxicant, releases formaldehyde (granted, at a lower level than trioxane) .The MSDS lists toxicity in animal tests when ingested, though via a quick google looks like an esbit tab is about a gram so the ~9 g they feed the rat would work out to be like eating 9-10 esbit tabs.

http://scorecard.org/chemical-profiles/summary.tcl?edf_substance_id=100-97-0#reg_coverage

http://www.cdc.gov/niosh/ipcsneng/neng1228.html

Has anyone ever done a review of the safety profiles of various fuels used by backpackers?