The most commonly used that I have seen are 39C & 40B. The difference is the denaturant used to denature the ethyl alcohol to render it unfit for human consumption. Different denaturants are used like brucine, quassin, IPA, methanol and so on and so forth. 39C is denatured with DEP and 40B is denatured with t-butyl alcohol & Bitrex.
These 2 are commonly used because there is hardly any or no smell of the denaturant. Secondly denatured with methanol can be used as methanol smells very close to ethanol but since methanol is a dangerous chemical it is generally avoided. Read it somewhere that methanol can be absorbed by the skin too and it can harm drastically. This last point though needs to be ratified by mentors and experts here. I have seen in some countries people dying of hooch consumption which is basically methanol or partly fermented liquor.
January 11, 2014 at 4:52 am
Thx for the answer. Is there any benefit of using SDA vs Ethyl Alcohol in perfumes except the cost? will using either 39C, 40B or pure Ehtyl alcohol bring the same result?
The advantage to using denatured alcohol is for the licensing, tax, analytical and record-keeping requirements, at least in the US.
Pure Ethyl Alcohol is more costly because of all the federal and state taxes on drinkable alcohol, Proving that you are not using/selling it in a drinkable form involves quite a bit of interaction with the BATF, and you have to keep track of every ounce if you want to avoid the taxes, etc.
Denatured alcohol, by definition, is unsafe to drink, so the record-keeping, etc. is much less.