Employers are increasingly using the hair follicle drug test rather than the more frequently used urine and blood tests to test for drug use by employees. Recent federal legislation will allow employers of commercial drivers to add hair testing as an option in addition to urine testing. The hair test offers some advantages over other forms of testing:
- Hair tests detect a much longer history of drug use. Hair stores a longer history of drug use than either urine or blood, which are limited to a few days for most drug types. Hair testing is the only drug testing method available that can provide a 90-day drug use history and is better at revealing chronic drug use.
- Hair tests are harder to cheat. There are many devices and chemicals available on the internet to assist people in “beating” the urine test. Because there are no privacy issues with removing a hair sample from a person’s head, the sample can be taken in full view.
There are, however, some disadvantages and pitfalls to hair testing:
- Hair testing cannot determine very recent drug use because hair grows so slowly, so it cannot be used for reasonable suspicion drug tests or post-accident testing.
- If retesting is required or desired, a retest of the original hair specimen might be difficult or impossible.
- Disciplinary action based on a hair test that reveals past, longer-term drug use can potentially violate the Americans with Disabilities Act if the employee has a drug addiction but is not a current user.
Employers who perform drug testing of employees should consider whether to include hair follicle testing as a method under certain circumstances.