| What Kinds of Tests Are Available? |
|
Urinalysis, the most common drug testing method, has been studied exhaustively and used extensively, has undergone rigorous challenge in the courts, and has proved to be accurate and reliable.
|
As a result, urinalysis currently is the only technique approved for drug testing in the Federal workforce.
Some employers, however, have already begun using other types of drug tests—on hair, sweat, and oral fluids. Each of these new tests has benefits as well as drawbacks.
|
| What Does Each Test Measure? |
Drug tests are used to determine whether a person has used alcohol or illegal drugs. Some tests show recent use only, while others indicate use over a longer period.
Each type of test has different applications and is used to detect a specific drug or group of drugs.
|
The Federal Drug-Free Workplace program, which serves as a model for accuracy and quality assurance in drug testing, relies on a urine test designed to detect the use of marijuana, opiates, cocaine, amphetamines, and phencyclidine (PCP).
Urine tests can also be used to detect alcohol, LSD, and cotenine, the major metabolite of nicotine.
|
| Test Type |
Pros |
Cons |
Window of Detection |
| Urine |
- Highest assurance of reliable results.
- Least expensive.
- Most flexibility in testing different drugs, including alcohol and nicotine.
- Most likely of all drug-testing methods to withstand legal challenge.
|
- Specimen can be adulterated, substituted, or diluted.
- Limited window of detection.
- Test sometimes viewed as invasive or embarrassing.
- Biological hazard for specimen handling and shipping to lab.
|
- Typically 1 to 5 days.
- Marijuana 7 to 10 days.
|
| Hair |
- Longer window of detection.
- Greater stability (does not deteriorate).
- Can measure chronic drug use.
- Convenient shipping and storage (no need to refrigerate).
- Collection procedure not considered invasive or embarrassing.
- More difficult to adulterate than urine.
- Detects alcohol/cocaine combination use.
|
- More expensive.
- Test usually limited to basic 5-drug panel.
- Cannot detect alcohol use.
- Will not detect very recent drug use (1 to 7 days prior to test).
|
- Depends on the length of hair in the sample. Hair grows about a half-inch per month, so a 1½-inch specimen would show a 3-month history.
|
| Oral Fluids |
Sample obtained under direct observation.
Minimal risk of tampering.
Non-invasive.
Samples can be collected easily in virtually any environment.
Can detect alcohol use.
Reflects recent drug use.
|
- Drugs and drug metabolites do not remain in oral fluids as long as they do in urine.
- Less efficient than other testing methods in detecting marijuana use.
|
- Approximately 10 to 24 hours.
|
| Sweat Patch |
- Non-invasive.
- Variable removal date (generally 1 to 7 days).
- Quick application and removal.
- Longer window of detection than urine.
- No sample substitution possible.
|
- Limited number of labs able to process results.
- People with skin eruptions, excessive hair, or cuts and abrasions cannot wear the patch.
- Passive exposure to drugs may contaminate patch and affect results.
|
- Patch retains evidence of drug use for at least 7 days, and can detect even low levels of drugs 2 to 5 hours after last use.
|
|
| Urinalysis |
|
Results of a urine test show the presence or absence of specific drugs or drug metabolites in the urine.Metabolites are drug residues that remain in the system for some time after the effects of the drug have worn off.
|
A positive urine test does not necessarily mean the subject was under the influence of drugs at the time of the test.
Rather, it detects and measures use of a particular drug within the previous few days.
|
| Hair Follicle Test |
|
Analysis of hair may provide a much longer “testing window” for the presence of drugs and drug metabolites, giving a more complete drug-use history that goes back as far as 90 days.
|
Like urine testing, hair testing does not provide evidence of current impairment, only past use of a specific drug. Hair testing cannot be used to detect alcohol.
|
| Sweat Patch |
Another type of drug test consists of a skin patch that measures drugs and drug metabolites in perspiration.
The patch, which looks like a large adhesive bandage, is applied to the skin and worn for some length of time.
|
A gas-permeable membrane on the patch protects the tested area from dirt and other contaminants.
The sweat patch is sometimes used in the criminal justice system to monitor drug use by parolees and probationers, but so far it has not been widely used in workplaces or schools.
|
| Oral Fluids |
Traces of drugs, drug metabolites, and alcohol can be detected in oral fluids, the generic term for saliva and other material collected from the mouth.
Oral fluids are easy to collect—a swab of the inner cheek is the most common way.
|
They are harder to adulterate or substitute, and collection is less invasive than with urine or hair testing.
Because drugs and drug metabolites do not remain in oral fluids as long as they do in urine, this method shows more promise in determining current use and impairment.
|
| Breath Alcohol |
|
The subject blows into a breath-alcohol test device, and the results are given as a number, known as the Blood Alcohol Concentration, which shows the level of alcohol in the blood at the time the test was taken.
|
Unlike urine tests, breath-alcohol tests do detect and measure current alcohol levels.
In the U.S. Department of Transportation regulations, an alcohol level of 0.04 is high enough to stop someone from performing a safety-sensitive task for that day.
|
| What Drug Tests Don't Measure |
The five-drug urine test used in the Federal Drug-Free Workplace Program does not detect all drugs used.
For example, it does not detect so-called "club" drugs such as gamma hydroxybutyrate (GHB) and Ecstasy, for example, although other urine tests can determine use of these drugs, and hair tests can easily detect Ecstasy use.
|
No standard test, however, can detect inhalant abuse, a problem that can have serious, even fatal, consequences.
(Inhalant abuse refers to the deliberate inhalation or sniffing of common household products—gasoline, correction fluid, felt-tip markers, spray paint, air freshener, and cooking spray, to name a few—with the purpose of "getting high.")
|