Dear nexians, I'm starting to worry about ethyl carbamate possibly being an issue in alcohol tinctures. I can't find any info on this being covered before - which may just be my inability to find what is already out there.

Ethyl carbamate can form by reacting urea with ethanol when heated, but I don't know if the reaction rate goes to 0 at cold temperatures. Ethyl carbamate is a 2A carcinogen according to the International Agency for Research on Cancer which means that it probably causes cancer in humans.

Low levels of ethyl carbamate are permitted in hard liquors (up to 125ppb). Ethyl carbamate can form in fermented products including wine (15ppb limit) and even bread (2ppb) when the yeast releases urea into the alcohol environment. 1ppb = 1 part per billion.

I bring this up because there are references to urea in mushrooms in the literature. One study on Hawaiian magic mushrooms measured up to ~0.5% urea in some magic mushroom species samples (attached, however note that they did not publish P.cubensis urea content I think). This seems like a significant quantity of urea that could be available for reaction with ethanol. Assuming as an example that 0.5% mushroom urea reacts, 3g of mushrooms delivered by alcohol tincture have as much ethyl carbamate as ~3000 shots (30ml) of hard liquor (plus or minus an order of magnitude and needs double checking).

Anyone have more info on this? Hopefully this has already been addressed (if so, sorry I can't find it) or there may be a known reason not to worry about it, such as the reaction equilibrium constant not allowing ethyl carbamate concentrations of the order of a fraction of a percent - so asking for any info anyone may have.

Many thanks.

This is a valid concern, thanks for pointing it out. As that paper suggests, it's the Panaeolus species that tend to contain more urea, but then I've not really seen any urea data for Psilocybe species.

Consider also that the maximum permitted concentration of 125ppb in spirits will have been calculated according to a safety factor of several thousand so a single shot of mushroom tincture should still be OK.

Thanks downwardsfromzero. We just discussed this in the chat and will be sending samples out to check for ethyl carbamate levels in tinctures (cold extract and boiled extract using same mushroom flush). Potency may be similar but the cold extract may have a lot less ethyl carbamate. Will report back in several weeks.

Any other info appreciated.

Ok, getting this going today. Documenting notes here. Feedback welcome, especially of I'm doing something wrong.

20.2g of recently dried mushrooms (B+ 2nd gen spores, set and forget monotub, coir/blakcow/verm/straw/gypsum/CaCO3) where covers in 75% ever clear and ground with 1g of vitamin C. Images below.

Plan:

Split gorund material in everclear into two parst A and B
For part A, perfrom 3x (11 hour room temp plus 1 hour boil) extracts. For part B perforem 3 x 12 hour room temp extracts. Filetering will be done with a squeezable fine muslim bag.
Reduce each part (A and B) to about 1g/ml
Send A and B out for analysis at t=0 and at 3 months.

It's admirable that you're jumping into action here seeing as most people work with Psilocybe cubensis these days.

Have you considered adding a urea spike to half of each sample to aid in overall quantification in the process?

I do think it would be at least as important to perform this test for the known high-urea mushrooms, namely the Panaeolus and Copelandia species.


Chemistry and harm reduction hand-in-hand - I absolutely love it!

Many thanks for the suggestion downardsfromzero.

Let's see how the first round of analysis goes. If no ethyl carbamate issues on the typical P.cubensis, we can force the issue by simulating mushrooms for which we know urea content for as you suggest. Pure urea seems easy enough to get. Also, in the meantime someone may find published urea content for cubensis.

Update: alcohol tincture has been run through MS. Unfortunately, nothing usefull could be obtained. Perhaps there is too much "stuff", a mess of proteins binded to all kinds of other molecules.

Sorry I could not shed any light the ethyl carbamate question.

Have a great day and cheers.