1. What is Hair Drug Testing?
Since hair growth is fed by the bloodstream, the ingestion of drugs
of abuse is revealed by analyzing a small sample of hair. Our
testing method measures the drug molecules embedded inside the hair
shaft, eliminating external contamination as a source of a positive
test result. Hair testing results cannot be altered with shampoos,
bleaches or other external chemicals.
2. What drugs are
included in a standard Hair Drug Test?
Cocaine (cocaine & benzoylecgonine), marijuana, opiates (Codeine,
Morphine & 6-monacteyl morphine), methamphetamine, (Meth/amphetamine
& Ecstasy), and phencyclidine (PCP). These five drug classes are
mandated for testing by the Federal Government.
3. What time period does a standard test cover?
A standard screen 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.
4. Are hair testing laboratories required to have FDA
There is a misconception that the FDA regulates workplace drug
testing laboratories such as DTS. The FDA’s responsibilities
actually lie in overseeing the safety of consumer products – not
workplace drug testing. DTS holds the highly-respected College of
American Pathologists accreditation as evidence of the highest
standards of testing procedures and processes.
5. How fast does head hair grow?
Studies indicate that head hair grows on the average approximately
1.3 cm (or 1/2 inch) per month. This growth rate varies slightly
(estimated at ± .2 cm per month),
consequently there is some (± 1 week) time variation possible.
6. How much hair is needed?
A standard screen 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.
7. How does Hair Testing compare to urinalysis?
The primary differences are
1) wider window of detection
2) inability to tamper with the test
Cocaine, methamphetamine, opiates and PCP are rapidly excreted and
usually undetectable in urine 72 hours after use. The detection
period for hair is limited only by the length of the hair sample and
is approximately 90 days for a standard screen.
At this time there are no known adulterants for hair tests. Since
hair tests analyze the drugs inside the hair shaft, external
contaminants/chemicals have no effect.
Additional advantages include non-intrusive collection procedures,
elimination of test evasion; greater accuracy through test
The combination of an increased window of detection and resistance
to evasion makes Hair Testing far more effective than urinalysis in
correctly identifying drug users.
8. How soon after use can a drug be detected in hair?
It takes approximately 4-5 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
9. What is the shortest time period that can be accurately
The minimum time period is approximately one month (1/2 inch). Body
hair can be used if head hair is too short for a test. If body hair
is used the timeframe represented by the test is approximately one
year, due to the different growth pattern in hair below the neck.
10. Can tests be run on people with little or no hair?
Hair can be collected from several head locations and combined to
obtain the required amount of 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.
11. Does body hair give the same type of results as head hair?
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 timeframe.
12. Can hair collected from a brush be used?
No, DTS requires a hair sample to be collected using proper
chain-of-custody protocols that will withstand a legal challenge.
DTS requires that the sample be submitted using DTS's Hair
Collection Kit. The test subject must initial the Sample Collection
Pouch to certify the authenticity of the sample at the time of
13. How does DTS' Laboratories establish its cut-off levels?
DTS follows the cut-off levels generally accepted industry-wide.
These levels are based in part by minimum detection levels for GC/MS
14. Does DTS' Laboratories perform Gas Chromatography Mass
Spectrometry (GC/MS) confirmation of all positive hair results?
DTS provides confirmation utilizing GC/MS for all specimens that
screen positive (opiates, PCP, methamphetamine, cocaine and
15. Can hair be affected by cross-reacting substances such as
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, DTS confirms all positive
results by GC/MS for methamphetamine, opiates, PCP,cocaine and
16. How effective is Hair Testing in detecting drug users?
In side-by-side comparison studies with urinalysis, hair drug
testing has uncovered significantly more drug use. In two
independent studies hair drug testing uncovered 4 to 8 times as many
drug users as urinalysis.
17. Does external exposure to certain drugs, like marijuana or
crack smoke, affect the Hair Test results?
To rule out the possibility of external contamination, DTS testing
(where appropriate) looks for both parent & metabolite (bi-product)
of drug usage. For marijuana analyses, DTS detects only the
metabolite (THC-COOH) . This metabolite is only produced by the body
and cannot be an environmental contaminant.
18. Is DTS Laboratories' internal chain-of-custody comparable
to a urinalysis laboratory test procedure?
DTS's internal chain-of-custody is modeled after Federal guidelines
(SAMHSA) as well as other accredited agencies (CAP).
19. How long are test reports kept on file?
Test reports are retained for a period of two years or as mandated
20. 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. Negative hair is stored for three months.
Positive hair is stored for one year.
21. What experience does DTS' Laboratories have in providing
Expert Witness Testimony?
DTS' Laboratories' forensic experts have qualified as expert
witnesses in Ohio, New York, California, Texas, Nevada, Oklahoma,
Alabama and Arizona in over 250 civil, criminal, and Superior Court
22. What other drugs are available to be tested in hair
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,
though, detection of these compounds is possible by special
arrangement with the Laboratory.
23. 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.