Alcohol Tests (Hair, Saliva, Sweat) Are They Accurate?

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

Discover the strengths and weaknesses of these different alcohol tests.


I.   Hair Alcohol Tests

II.  Saliva Alcohol Tests

III. Sweat Alcohol Tests

IV.  Summary

V.   Resources

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.

    • Alcohol hair tests are designed 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? That 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. That is, for use in the Department of Transportation (DOT) Federal Mandated Drug Testing program. But 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.

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. Of course, it’s not proof. 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

Science Articles

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