Sciencemadness Discussion Board

Pure Menthol Crystalline ( Menthol arvensis ) - Carbon Monoxide ?

mentholmadness - 8-1-2013 at 18:18

Hi guys,

I'm an aspiring new essential oil chemist. I've been reading alot on essential oils series of papers. However i am getting mixed answers in the release of Carbon Monoxide when pure menthol is melted.

Can anyone shine some light on this question ?.

I have to say the aroma of the crystal itself being melted on metal incense plate with the flame underneath the plate is much stronger than the oil form being heated. BUT i am afraid this will produce CARBON MONOXIDE, If this is true and carbon monoxide is released when the crystal form is melted is there any way to stop it ? Would reducing the purity of the menthol effect the amount of carbon monoxide released, IF it is released at all.

kristofvagyok - 8-1-2013 at 18:53

Quote: Originally posted by mentholmadness  
However i am getting mixed answers in the release of Carbon Monoxide when pure menthol is melted.

Why would CO form if we would melt menthol? I have melted/recrystallized/worked with menthol and never ever experienced such thing. Where is this info from?

mentholmadness - 8-1-2013 at 19:14

Sorry to be conflicting Kristofvagyok,

I was just going from the the numerous MSDS reports. More specifically

http://cdn.shopify.com/s/files/1/0159/4180/files/msdsmenthol...

Quote: " HAZARDOUS COMBUSTIBLE OF DECOMPOSITION PRODUCTS

FORMS CARBON MONOXIDE AND/OR DIOXIDE UPON BURNING

More importantly

7. Toxicological Properties/Information:

DANGER! May be fatal if swallow. Harmful if inhaled.

Oral (rat), LD50 = 800 mg/kg

Skin (rabbit), LD50 >5 g/kg

Causes irritation to the skin, eyes and respiratory tract. May also cause allergic reaction.

Estimated fatal dose is 2g per average human.

Source : http://www.newdirectionsaromatics.ca/msds/mentholcrystalmsds...

Thanks for any input and/or critism

mentholmadness - 8-1-2013 at 19:21

By the way i would love to know that it can't release enough CO ppm to be even remotely dangerous. However i thought i was poisoned yesterday. Anyone else have experiences with inhaling menthol crystal smoke ?

Mailinmypocket - 8-1-2013 at 19:25

Perhaps smokers of menthol cigarettes? :P

Unless you are in a warehouse with drums of menthol burning and no escape, don't worry about the CO poisoning.

kristofvagyok - 8-1-2013 at 19:26

Quote: Originally posted by mentholmadness  
FORMS CARBON MONOXIDE AND/OR DIOXIDE UPON BURNING

DANGER! May be fatal if swallow. Harmful if inhaled.

Oral (rat), LD50 = 800 mg/kg

Skin (rabbit), LD50 >5 g/kg

Estimated fatal dose is 2g per average human.

Burning is NOT equal to melting. When you burn menthol (it burns quite well) it will produce CO in trace quantities.

The LD50 data shows only one thing: it is perfectly safe and the estimated 2g/human is just estimated. It would hurt really, but I don't think that anyone would die from 2g menthol if swallowed (I didn't say that try it out).

I know a prof who had a headache what didn't passed away. He was in the lab and tried out something: grabbed the mentol and rubbed his nape with a few gram. The headache passed away in a few minute.

mentholmadness - 8-1-2013 at 19:32

Firstly, Thankyou everyone for the speedy replies.

" Perhaps smokers of menthol cigarettes " - Actually from what i understand that is totally different i am talking about putting a menthol crystal on a heated surface until it melts to liquid

" Burning is NOT equal to melting " - Well just so i can separate the differences, You do know i am just heating a solid crystal on a dry metal plate and it is turning to liquid and giving of small amounts of smoke

Mailinmypocket - 8-1-2013 at 19:56

It was sort of a joke but you got me thinking and although Wikipedia is not a definite reference:

"A menthol cigarette is a cigarette flavored with the compound menthol, a substance which triggers the cold-sensitive nerves in the skin (...)"

Either way, a candle burning creates those gases, as do many combustible things when they burn. I really wouldn't worry about melting crystals and having little bits of vapor/smoke.

mentholmadness - 8-1-2013 at 20:05

Okay, Thank you Mallinmypocket !

I appreciate your replies and input.

I love the smell of menthol crystals but the best thing about them are there dimensions.

Does anyone know of other organic compounds that recrystallize similarly to Menthol like this http://antiqueremedies.blogspot.com.au/2011/03/homemade-tige... ? But they need to smell nice maybe strawberry ?

I've been wondering if menthol crystals are created from Peppermint oil , Distillation and freezing maybe it will be the same for some other Essential oils. Strawberry crystals or even Lavender ?

Would they keep the same characteristics ? Same shape and size ?

[Edited on 9-1-2013 by mentholmadness]

Adas - 9-1-2013 at 09:07

Quote: Originally posted by mentholmadness  
Okay, Thank you Mallinmypocket !

I appreciate your replies and input.

I love the smell of menthol crystals but the best thing about them are there dimensions.

Does anyone know of other organic compounds that recrystallize similarly to Menthol like this http://antiqueremedies.blogspot.com.au/2011/03/homemade-tige... ? But they need to smell nice maybe strawberry ?

I've been wondering if menthol crystals are created from Peppermint oil , Distillation and freezing maybe it will be the same for some other Essential oils. Strawberry crystals or even Lavender ?

Would they keep the same characteristics ? Same shape and size ?

[Edited on 9-1-2013 by mentholmadness]


It is not possible to make "lavender crystals", unless you freeze lavender essential oil.

I don't know about strawberry, but look at this. Raspberry Ketone The preparation is even described somewhere on the forum.

I have strong impression that the unsaturated form of this ketone is used in many shampoos (I am currently using one :D), because it is said to have bubblegum-like smell.

[Edited on 9-1-2013 by Adas]

smaerd - 9-1-2013 at 09:13

Vanillin is pretty cool too. A fun easy reaction with it is the aldol condensation with acetone. There are tons of fragrance chemicals out there to explore :).

kristofvagyok - 9-1-2013 at 11:34

Quote: Originally posted by smaerd  
Vanillin is pretty cool too. A fun easy reaction with it is the aldol condensation with acetone. There are tons of fragrance chemicals out there to explore :).

I'm just making some zingerone from vanilline and I would say an important thing: the Aldol reaction with acetone didn't offered the product what I wanted. Actually non of the vanilline reacted while performing the recipe of Ozonelabs.

smaerd - 9-1-2013 at 12:37

I PM'd you my experimental I got a low yield on that transformation(15.4%) but I did the crystalization sloppy. my product was golden flakey crystals with only a slight vanilla like odor.

[Edited on 9-1-2013 by smaerd]

mentholmadness - 9-1-2013 at 20:06

Okay guys just so i can make it more specific rather than using ketones or acetones


If i freeze other essential oils similar to the way menthol is frozen (-60C) When they recrystallize will they melt at room temperature or will they stay nice and bold like menthol shards

[Edited on 10-1-2013 by mentholmadness]