Passive Inhalation & Hair Testing

Drug testing private- and public-sector employees has been commonplace since the early 1990s. Increasingly, parents are testing their children for drug use. Although it's more common to test urine, sometimes drug tests are conducted on the subject's hair because it can be more accurate.

History

• In 1989, the U.S. Supreme Court ruled that drug testing government employees does not violate citizens' 4th Amendment rights. Likewise, employees in private companies have little protection against drug testing in most states.

As a Defense

• Being around marijuana smoke could cause you to test positive.

  Passive inhalation is often claimed as a defense by people who tests positive. It is possible to find trace amounts of the chemical in marijuana, THC, in the hair of those were around secondhand smoke. However, the amount is usually well below what it would normally be for a marijuana smoker.

Results

• Sometimes, THC can be found in hair after passive inhalation.

  Technically, the hair of someone who has been around marijuana smoke could test positive for several months after exposure. It depends on how close the person was to the smoke, the concentration of THC in the marijuana and the length of the time of exposure.

Metabolites

• For more accurate results from hair tests, the tester might check for metabolites instead of THC itself.