Alcohol Tests (Hair, Saliva, Sweat) Accurate? What You Need to Know to Protect Yourself

Alcohol tests of the breath estimate blood alcohol concentration or BAC. Only blood tests can actually measure it. Other tests can also estimate drinking. They include hair, saliva and sweat tests.


I.   Hair Alcohol Tests

II.  Saliva Alcohol Tests

III. Sweat Alcohol Tests

IV.  Summary

V.   Resources

Discover the strengths and weaknesses of these different alcohol tests.

I. Hair Alcohol Tests

Hair alcohol tests can’t distinguish between not drinking and moderate drinking. They can only suggest if frequent heavy drinking has occurred. We should keep several important points in mind.

  • Designers of alcohol hair tests engineer them to give up to 10% false positive and 10% false negative results. So they expect one of every five tests to give false results.
  • Bleached, dyed, permed, or frequently shampooed hair causes the accuracy of alcohol hair tests to drop even more.
  • It is possible that the tests may give false positive results. That is, falsely report drinking when none has occurred. This can happen from coming into contact with products containing alcohol.
  • The alcohol test results are never proof of drinking.1

II. Saliva Alcohol Tests

Saliva or oral fluid alcohol tests can generally detect alcohol consumption during the previous six to twelve hours. But the federal Food and Drug Administration (FDA) has not approved them. Nor has the  Substance and Mental Health Services Administration (SAMSHA) approved them for use in the Department of Transportation (DOT) Federal Mandated Drug Testing program. However, the Department of Labor (DOL) does permit saliva tests in on-site testing.

III. Sweat Alcohol Tests

After drinking, some alcohol leaves the body through sweat or perspiration. Therefore, the collection of sweat over time can produce a record of alcohol use. The FDA has approved sweat testing methods for drugs. They include a sweat patch collection device. People can wear the patch for up to several weeks. They then remove it and sent to a lab for analysis.

Unfortunately, a major problem with sweat alcohol tests is inconsistency of results from person to person. This low reliability causes low validity of results. That is, accuracy of results. There are no national or other standards for detecting alcohol in sweat. Also, certification programs for sweat testing do not exist.

IV. Summary

alcohol testsIs the question whether a person has consumed alcohol heavily and frequently over a period of at least three months?

Then hair testing might provide useful, although inconclusive, evidence. Is the question is whether a person is currently consuming alcohol at any level?  Then the options for alcohol tests increase. Breath, urine, saliva, or sweat testing could be appropriate. The breath test provides low-cost and quick results.

But it is essential to recognize the high level of inaccurate results from each of these alcohol tests. That’s because they all produce estimates rather than actual measurements of alcohol in the blood itself.

V. Resources

Web Pages

EtG Urine Alcohol Test Unreliable Warns Federal Agency.

Sensitivity of commercial ETG testing.

U.S. Department of Labor: Workplace Drug Testing.

Popular Books

Dasgupta, A. Beating Drug Tests and Defending Positive Results. Totowa, NJ: Humana, 2010.

Jenkins, A. and Goldberger, B. On-site Drug Testing. Totowa, NJ: Humana, 2002.

Karch, S. Workplace Drug Testing. Boca Raton, FL: CRC, 2008.

Karch, S. Forensic Issues in Alcohol Testing. Boca Raton, FL: CRC, 2008.

Kintz, P. (Ed.) Drug Testing in Hair. Boca Raton, FL: CRC Press, 2006.

Mur, C. Drug Testing. San Diego: Greehaven, 2006.

Technical Articles

Albermann, M., et al.  A procedure for the determination of fatty acid ethyl esters in hair. J Chromat Sci., 2014, 52(9), 955-960.

Auwarter, V., et al.  Fatty acid ethyl esters in hair as markers of alcohol consumption. Clin Chem., 2001, 47(12), 2114-2123

Drummer, O. Drug testing in oral fluid. Clin Biochem Rev., 2006, 27(3), 147-159.

Leyton V, et al.  Hair drug testing in the new Brazilian regulation. Addict., 2015. ePub. PMID: 25967396.

Swan, N. Sweat testing may prove useful in drug-use surveillance. NIDA Notes, 1995, 10(5), 1.


1 Lamb, H. Hair Strand Testing for Alcohol. Family Law Week, 2010.