Addiction

That is an intriguing question. Hair alcohol tests (HAT) look for a combination of EtG and FAEEs*. Alcohol is never found in hair. Unlike testing for other drugs, HAT uses only the base of the hair sample, 1/2 inch. In the US, introduced in 2008, it is a questionable science...

That being said, most of the labs offering this test will claim detection in the 90 day range.. whereas if the test is performed properly it is limited to 30 days.

How EtG and FAEEs get into the hair is an unknown. The rate of incorporation is unknown... that is to say how much alcohol must be consumed before it can be incorporated into the hair. There is also a body of evidence to indicate that human hair is influenced by cosmetic products that contain alcohol (that's most). (See Sporkert 2011, Positive EtG findings in hair as a result of cosmetic treatment Forensic Science International).

HAT is a very dubious system and all of the important questions are still awaiting answers.

Wish I could be more responsive but the data simply isn't there.

Who is using this test?

*Fatty acid ethyl esters

Hi Dr Bill, you mentioned the test should cover 30 days. What is the effect of it covering 90 days? Does that increase or decrease the probability of a positive result if a person drinks moderately. For example maybe 75 grams every week? But all at once. That works out to be 10 grams per day and in Canada, they are saying over 20 grams per day of the cut-off.

But I know these tests can be crazy. I had one done one month which was under the cut-off and although I did not change my habits much, the next month it came back over twice as much, way over cut-off.

Is there any articles about the effect of UV rays?