Hair Follicle Drug Testing Facts
Here are a few drug testing facts you should be aware of before taking the hair drug test.
When it comes to drug testing, urine drug testing is the most common, but also the most prone to cheating. While urine drug testing is used to identify recent drug use, hair follicle drug testing, or just hair drug testing, can identify the use of drugs over a span of 90 days or longer.
What does a hair drug test screen for?
Hair drug tests can screen for:
- nicotine and cotinine
- opioids (codeine, morphine, 6-acetylmorphine)
- phencyclidine (PCP)
When is hair drug testing used?
Hair drug tests can be used by employers, for legal & forensic testing, for medical testing, and for measuring patterns of illegal & prescription drug use. Because collecting hair samples is so easy, there are a number of federal, state, and local laws that dictate how and when hair drug testing can be performed and the need for consent.
Drugs and / or their metabolites can remain in hair for months and even years, so a hair drug test is not a good test to measure current intoxication levels and should not be used to identify on-the-job drug use. This is especially true for follicle drug screens, since drugs can take 7-10 days from initial exposure to show up in the hair.
What if I am bald?
If you don't have any hair on your head, facial hair, armpit hair, and even pubic hair can be used instead. The shorter the hair, the more hair that needs to be collected. People who shave their entire body obviously cannot provide a sample for a hair drug test.
How does the process work?
Hair is typically collected in a lab or hospital setting. If it is collected at your workplace, it will be done under observation using a kit and mailed to a lab for testing. Scissors will be used to cut about 100 hairs from your head (more if hair is collected from other areas). The person collecting the sample should wear gloves and practice sterile techniques to avoid contamination. Also be sure to inform the lab of any medications, supplements, or hair treatments that might affect test results.
Once a sample has been collected, it is sent to a lab for testing. A negative result can usually be confirmed within 24 hours of hair removal. If the test is positive or inconclusive, it may take 72 hours or more for confirmation. Confirming a positive result involves gas chromatography/mass spectrometry (GC/MS) and identifies the specific drugs or chemicals used. Inconclusive results are uncommon, but if they occur, you will need to repeat the process.
Are hair drug tests accurate?
Yes, these tests are very accurate. As part of the process, the hair is thoroughly washed to remove environmental contaminants that may cause false positives. Even if the initial screen comes up positive, the follow-up GC/MS rules out common foods like poppy seeds and hemp seeds that can cause false positives on urine drug tests. The one possible exception comes from a study indicating hair drug tests may incorrectly flag marijuana use. However, if you completely abstain from drugs and do not take prescription medications, it is unlikely that you will ever test positive.
Can I cheat the test?
While there are shampoos and detox products in the marketplace that claim to eliminate traces of drugs from your hair, you should be skeptical. Hair drug tests are extremely good at accurately identifying patterns of drug use, so, unless you just used a drug within a few days of the test, it's likely to show up in your hair follicles. Since these tests are performed under observation, it's also unlikely that you'll be able to substitute someone else's hair. Your only option for "beating" this test is not having any hair that can be used for the test, however, this may cause suspicion and put you under greater scrutiny.
If you DO decide to try a commercial product, or aren't sure what your test result will be, you can always order a test personally to see what the results will look like before your employer performs the test.
Can I challenge the result?
As with any test, there's always the possibility of a mix-up at the lab or before the sample is sent to the lab. If you disagree with the result, your best option may be having the test repeated on location at the lab. This minimizes the potential for mix-ups. Keep in mind that, due to intense scrutiny, labs likely have processes that allow them to rule out common errors. If you test positive, and know you've used drugs, challenging the results may not be your best strategy.
These are just a few of the things you should know about hair drug tests and how they work. Forewarned is forearmed, and the better you understand these tests, the better chance you’ll have of passing them. Contact us to learn more!