Hair testing has been around for years and is rapidly becoming a powerful tool for the detection of drug and alcohol abuse. The U.S. trucking industry has approved hair testing and ATA (American Trucking Association) has said that it will,
“allow trucking companies to use a highly effective tool—hair testing—to meet federal requirements and prevent drug users from getting behind the wheel of a truck.” *see below
The Drug Free Commercial Truck Driver Act of 2015 (s.806 and H.R.1467) and The FAST Act (Fixing America’s Surface Transportation Act) of 2015, are important state and federal guidelines for DOT hair testing.
Hair growth is fed by the bloodstream and ingested drugs present themselves in a person’s circulatory system, therefore trace amounts of the drugs become entrapped in the core of the hair shaft, in amounts roughly proportional to the drugs ingested.
Testing Children for Passive Drug Exposure
ChildGuard is a hair test designed to register passive exposure which gives us information about a child’s environment. This passive exposure drug test represents significant advance information gathering for child abuse investigations, child welfare applications and is widely used in legal situations. A positive Child Guard result indicates that the child has experienced one or more of the following:
- Passive inhalation of drug smoke
- Contact with drug smoke
- Contact with sweat or sebum (skin oil) of a drug user
- Contact with the physical drug substance
- Accidental or intentional ingestion of illegal drugs
Q & A
(Q) 1. What is the window of detection on a hair test?
(A) Drug use can be detected for months and even years, depending on the length of the hair sample. A standard test covers a period of approximately 90 days and the hair sample is cut as close to the scalp as possible and the most recent 1.5 inches are tested.
(Q) 2. How soon after use can a drug be detected in hair?
(A) It takes approximately 7-10 days from the time of drug use for the affected hair to grow above the scalp. Body hair growth rates are generally slower and cannot be utilized to determine a timeframe of drug use.
(Q) 3. How does Hair Testing compare to urinalysis?
(A) The primary differences of hair testing compared to urinalysis are:
1. Wider window of detection - When hair and urine results were compared in “side-by-side” evaluations, 5-10 times as many drugs users were accurately identified with hair testing compared to urine.
2. Inability to tamper with the test - Unlike urine, properly collected hair samples cannot be easily substituted, adulterated or diluted. Ways to beat urine tests are widely publicized and drug free urine and adulterants can easily be purchased. Most drugs users know that the simplest way to beat a urine test is to just abstain from drug use for 3 days.
3. Non-Intrusive Sample Collection - No embarrassment of providing a urine sample.
4. Cost-Effectiveness - Studies have revealed that each drug user can cost a company between $7000.00-$10,000.00 annually. Hair testing with its high positive results creates cost savings for the company.
(Q) 4. What drugs are included in a standard Hair Drug Test?
(A) Years ago, the laboratories only tested these five drug panels: Cocaine, marijuana, opiates (Codeine, Morphine & 6-monacteyl morphine), methamphetamine (Meth/amphetamine & Ecstasy), and phencyclidine (PCP).
However, today, our laboratories have added expanded opiates to their panel of testing, due to a significant increase in the abuse of prescription drugs. Additional drug panels are available, including tramadol.
(Q) 5. How effective is hair testing in detecting drug users?
(A) Testing is up to 5-10 times more effective in identifying drug users than urinalysis.
(Q) 6. Can hair tests be performed on people with little or no hair?
(A) Yes, Hair can be collected from several scalp locations and combined to obtain the required amount of hair. In addition, body hair may be used as a substitute to head hair.
(Q) 7. Does body hair give the same type of results as head hair?
(A) Yes, body hair can be used to test for the five standard drug classes, though body hair growth patterns are different than head hair. Most body hair is replaced within approximately one year. This means a test done with body hair will be reported as drug usage during approximately one year timeframe.
(Q) 8. Can hair collected from a brush be used?
(A) Yes, but the test will be reported as having an “anonymous” donor. We cannot attribute the sample to any specific person and we cannot determine the timeframe of the test, so the test result is not legally defensible. The test will only report that the sample submitted had the reported drug metabolite components.
(Q). 9. Does external exposure to certain drugs, like marijuana or crack smoke, affect the Hair test results?
(A) To ensure accurate hair testing results, it is important to eliminate the possibility that the results are being influenced by drugs deposited on the outside of the hair from contamination versus drugs deposited on the inside of the hair from ingestion. This is critical to provide accurate test results and to prevent false positives.
To rule out the possibility of external contamination, some laboratories look for both parent & metabolite (bi-product) of drug usage. For marijuana analyses, labs detect only the metabolite (THC- COOH). This metabolite is only produced by the body and cannot be an environmental contaminant.
Some hair testing laboratories utilize an extensive washing procedure to remove and/or account for any external contamination.
(Q) 10. Can hair be affected by cross-reacting substances such as over–the-counter medications?
(A) Enzyme-immunoassay antibodies (EIA) like those used to test urine are used for the initial screening test for drugs of abuse in hair; therefore, the potential for substances such as over-the-counter medications to cause a false positive screening result does exist. To eliminate the possibility of reporting a false-positive due to cross-reactivity, Laboratories will always confirm all screening positive results by GC/MS for any drugs tested.
Nail Drug Testing
Nails, a keratinized protein like hair, are emerging as a popular specimen type, especially for court ordered tests, and is less popular for the workplace. Using fingernail samples for toxicological analysis and pharmacokinetic studies has been around for decades.
When drugs are ingested, biomarkers can be found in nails as early as 1-2 weeks after ingestion. The time during which drugs are ingested can be detected depending on the substance used, the amount used, and personal metabolism.
A nail alcohol test for EtG, a biomarker test that can detect the presence of ethyl glucuronide in variety of specimen types, promises a much wider window of detection. It is becoming more popular for testing in the criminal justice system and in treatment facilities. Drugs are distributed via the blood supply to the nail cells and the nail bed. Nails grow not only in length but in thickness as well. As the nail grows in thickness, it creates layers of drug history.
There are a limited number of references in the literature that fully describe the window of detection, but the available literature indicates that some drugs wash out as quickly as 3 months, while some can be retained for many more months.
The detection limit depends on the age of the nail material, which for the average person is 5-6 months minus the washout rate. However, some individuals may have slightly faster nail growth while others may have somewhat slower. Also, a major consideration in the detection window is the original drug exposure level.
What we know is that fingernails have a long window of detection: longer in some instances than hair. There are many factors that determine the window of detection.
Q & A
How far back does the fingernail test go?
Nails are keratinized protein, and nails are porous. Compounds become trapped and bound within the structure of the nail. The entire process takes up to 6 months, depending on the health of the individual. Compounds are incorporated into the fingernail via four main routes:
- Environmental exposure…if someone is handling a drug or around someone smoking a drug, the substance gets on the nail and into the pores, and binds to the keratinized protein.
- Perspiration and skin oil surrounding the nail…causes deposits of the drug and drug metabolite into the nail.
- Blood flow in the germinal matrix…deposits drug and drug metabolite into the nail when it is formed.
- Drug and drug metabolite deposits…form on the underside of the nail plate, due to the blood flow to the nail bed.
These four very different routes of incorporation are superimposed in layers, rendering a very complex drug history.
In conclusion, for fingernail clippings there is a potential for a detection window of up to 6 months. Just like hair and urine, a negative result is not proof of abstinence, just the lack of evidence. A positive fingernail result for most drugs may be explained by drug use at any point during the 6 months prior to the collection. Since the clipping contains the entire drug history in the growth of the nail, a nail scraping is not necessary.