PYDT Hair Follicle Drug Testing FAQ
Since hair growth is fed by the bloodstream, the ingestion of drugs of abuse is revealed by analyzing a small sample of hair. Testing method measures the drug molecules embedded inside the hair shaft, eliminating external contamination as a source of a positive test result.
It is becoming increasingly common for employers and the courts to ask for a Hair Drug Test. Testing for illegal substances in hair gives you a greater time frame of detection than urine, blood and saliva. In fact, you can often detect drugs in hair for several months - if not years, if the hair is long enough. Normally 90 days is all that is requested. However, some States require 120 days.
What time period does a standard test cover?
A standard test covers a period of approximately 90 days. The hair sample is cut as close to the scalp as possible and the most recent 1.5 inches are tested.
What types of hair drug test are they?
A two-tiered testing process is used:
1) A portion of the hair sample is screened using an Enzyme Linked Immunosorbent Assay (ELISA) - a reliable and proven methodology for routine drug testing.
2) Any samples that are presumptively positive in the screening process are then confirmed, utilizing another portion of the hair sample, with either gas chromatography/mass spectrometry (GC/MS) or gas chromatography/mass spectrometry/mass spectrometry (GC/MS/MS).
Is all hair testing a like?
No, Psychemedics uses its patented digestion method to liquefy the hair, thereby effectively releasing essentially all the drugs present for analysis, and increasing detection capabilities. Other laboratories may leach drug from the hair, leaving behind or destroying some of the drug in the process. Psychemedics also employs an extensive wash procedure on test samples, and analyzes the wash to ensure that any potential contamination has been removed or taken into account.
Can hair be affected by cross-reacting substances such as over-the-counter medications?
Enzyme-immunoassay antibodies (EIA), similar to 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, most labs confirms all positive results by GC/MS for methamphetamine, opiates, PCP, cocaine and marijuana.
What drugs are tested for by the hair drug test?
Amphetamines: (Amphetamine, Methamphetamine, MDMA (Ecstasy) and MDA (MDEA, Eve and 3,4-methylenedioxyamphetamine)
Opiates: (Codeine, Morphine, 6-monoacetylmorphine Morphine including Heroin, Oxycodone, Hydrocodone and Hydromorphone)
Cocaine: (Cocaine & Benzoylecgonine metabolites)
Marijuana metabolite: (THC Carboxylic Acid metabolite)
PCP: (Phencyclidine, Angel Dust)
These five drug classes are mandated for testing by the Federal Government
**Note** Alcohol can now be detected in a hair drug test.
Can hair testing detect Ecstasy?
Yes, Ecstasy is reported under the “Amphetamines” group.
What other drugs are available to be tested in hair analysis?
Currently, nicotine, methadone, simple benzodiazepines, tricyclic antidepressants assays and mescaline have been detected in hair.
However, many details such as cutoff levels and dose response relationships have not yet been established for these compounds. Currently these assays are in the Research and Development process.
Does external exposure to certain drugs, like marijuana or crack smoke, affect the hair test results?
To rule out the possibility of external contamination, the testing labs (where appropriate) looks for both parent & metabolite (bi-product) of drug usage. For marijuana analyses, they can detects only the metabolite (THC-COOH) . This metabolite is only produced by the body and cannot be an environmental contaminant.
Can hair be affected by cross-reacting substances such as over-the-counter medications?
Enzyme-immunoassay antibodies (EIA), similar to 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, labs confirms all positive results by GC/MS for methamphetamine, opiates, PCP, cocaine and marijuana.
How much hair is needed?
A standard test with GC/MS confirmation requires 60+ milligrams
of hair or approximately 90 to 120 strands. The thickness of different types of head hair (thick coarse vs. thinning fine) is the reason for this variation.
How long does the Laboratory retain positive (non-negative) specimens?
Positive specimens are retained for a minimum of 12 months (the same as non-negative urine specimens.) Depending on the lab and it’s policies, some may retain it from 2 - 5 years.
What is done with the excess hair that is not tested?
The hair not used from the time period being tested (i.e. three months equals 3.9 cm) is stored in the chain-of-custody sample acquisition pouch. Hair is stored for a two year period.
Will the test results really reflect drug use over the past 90 days?
Yes. Hair follicles underneath the scalp are surrounded by a dense network of capillary blood vessels. Drugs in the bloodstream are able to incorporate and bind to the hair follicles underneath the scalp. It takes approximately 5-10 days for hair containing drug to reach the outer environment on top of the scalp to be collected based on the average rate of head hair growth.
How fast does hair grow?
Head hair grows approximately 1.3 cm or a ½ inch per month. The standard length of hair tested by the laboratory is the first 3.9 cm or 1½ inches from the root end. Therefore, a hair analysis of 3.9 cm covers a time span of approximately 90 days and detects a pattern of drug use over this timeframe.
Many employers find it useful to test both hair and urine for pre-employment purposes. Urine is useful for detecting recent or new drug use (the last 1-3 days except Marijuana, which is longer) and hair for providing an approximate three-month drug history of repetitive use.
Can body hair be used for hair drug testing?
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 a one year time frame.
A sample of body hair an inch and a half in length will give you a history of about 5-6 months, as body hair grows more slowly than hair on the head. This also means that it takes longer for drugs to grow out into the body hair than the head hair.
In addition, body hair may be used as a substitute to head hair. In the rare case where no hair is collectable, complete urine/adulteration testing may be utilized.
How long does it take drugs to enter the hair?
It takes about 5-7 days for the hair affected by the drug use to grow out above the scalp. In the case of body hair, it takes longer.
Body hair growth rates are generally slower and cannot be utilized to determine a time frame of drug use.
What is the turnaround time to get my results back?
Normally 5 to 7 days. Some labs can return negative results within 24 hours of receipt and positive results are confirmed, reviewed, and reported within 48-72 hours of receipt.
The laboratory receives the samples via overnight courier and US Mail.
What is the shortest time period that can accurately be evaluated?
In most situations the minimum time period is approximately one month. A hair test does not determine drugs used on a particular day or week.
Can tests be run on people with little or no hair?
Yes. Hair can be collected from several locations on the head and combined to obtain the required amount of hair. If head hair is not available, certain body hair can be used as an alternative. ie: Chest, Arm Pits, Legs.
Does hair color affect results?
Hair color is determined by the amount of melanin in the hair. It has been shown experimentally, through actual hair samples, as well as determined in court that hair color has NO basis in fact.
Does chemical treatment of the hair affect the test results?
Commonly used hair procedures (e.g., shampoos, conditioners, sprays, mousses and gels) have no significant effect on results. Normal hair treatments such as bleaching, perming and dyeing generally will not significantly lower the quantitative results. If the protein matrix of the hair has been damaged to the point of breaking (cortex damage) the level of drug can be significantly affected. However, severely treated or damaged hair can be readily identified.
How long are test reports kept on file?
Test reports are retained for a period of two years or as mandated by law.
Has hair drug testing been admitted in court?
Yes. Hair testing for drugs of abuse has been routinely admitted in both state and federal courts, as well as arbitrations and agency hearings. The test results are routinely upheld. Some court systems use hair analysis as part of their probation, parole, and diversionary programs.
Is hair testing included in SAMHSA/NIDA guidelines?
Under SAMHSA/NIDA’s current guidelines for federally-mandated testing, urine is the only specimen included for testing certain government employees and that segment of private sector testing that falls under the Department of Transportation or other agency guidelines.
In a November 2008 press release, SAMHSA states that HHS will continue to pursue substance abuse testing using alternative matrices, including hair specimens, and anticipates issuing further revisions to the Mandatory Guidelines addressing the use of hair specimens.
Are Hair Drug tests regulated by the Food and Drug Administration (FDA)?
The FDA sets minimum standards for drug tests used in a workplace setting, requiring that they be performed with screening tests that have been approved, cleared, or otherwise recognized by the Food and Drug Administration as “accurate and reliable”.
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