This is part 3 of a 4 part series on workplace drug testing.
What drugs do tests detect?
Testing conducted according to the Substance Abuse and Mental Health Services Administration’s (SAMHSA) guidelines checks for five illicit drugs plus, in some cases, alcohol (ethanol, ethyl alcohol, booze). These five illicit drugs are:
- Amphetamines (meth, speed, crank, ecstasy)
- THC (cannabinoids, marijuana, hash)
- Cocaine (coke, crack)
- Opiates (heroin, opium, codeine, morphine)
- Phencyclidine (PCP, angel dust)
However, most private employers are not limited in the number of substances they can test for and may include drugs that individuals legitimately and/or therapeutically take based on a physician’s prescription. Although most private employers can test for any combination of drugs, there are commonly selected “panels.”
The typical 8-Panel Test includes the above-mentioned substances plus:
Barbiturates (phenobarbital, butalbital, secobarbital, downers)
Benzodiazepines (tranquilizers like Valium, Librium, Xanax)
The typical 10-Panel Test includes the 8-Panel Test plus:
Methadone (often used to treat heroin addiction)
Propoxyphene (Darvon compounds)
Testing can also be done for:
Hallucinogens (LSD, mushrooms, mescaline, peyote)
Inhalants (paint, glue, hairspray)
Anabolic steroids (synthesized, muscle-building hormones)
Hydrocodone (prescription medication known as Lortab, Vicodin, Oxycodone)
MDMA ( commonly known as Ecstasy)
How long are drugs in one’s system?
Drugs have certain “detection windows”—the amount of time after ingestion during which evidence of their use can be detected by a drug test. Though it might not be wise to publicize detection windows and invite employees who may use drugs to push their limits, when implementing drug testing, it is important to understand them. For instance, alcohol is absorbed and eliminated more quickly than other drugs. This is why post-accident testing procedures often require testing for alcohol to occur within two hours. Other drugs are eliminated from the system at different rates and thus detectable for different periods of time, often long after the drug’s effect has worn off. The following are estimates of the length of time that certain drugs are detectable:
Alcohol – 1 oz. for 1.5 hours
Amphetamines – 48 hours
Barbiturates – 2-10 days
Benzodiazepines – 2-3 weeks
Cocaine – 2-10 days
Heroin Metabolite – less than 1 day
Morphine – 2-3 days
LSD – 8 hours
Marijuana – casual use, 3-4 days; chronic use, several weeks
Methamphetamine – 2-3 days
Methadone – 2-3 days
Phencyclidine (PCP) – 1 week
How does a drug test determine if a person has been using substances? What are cut-off levels and what do they determine?
Aside from a breath alcohol test, drug testing does not determine impairment or current drug use. Rather, drug testing determines a specified amount or presence of a drug or its metabolite in urine, blood or an alternative specimen. There is a minimum measurement applied to drug testing so that only traces of a drug or its metabolite above a specified level is reported as positive. This measure is known as a “cut-off level,” and it varies for each drug. Setting cut-off levels involves understanding the expected results of testing and determining the needs of the employer’s drug-free workplace program. For instance, if a cut-off level is set low, test results will come back with more “false positives” as some “passive” users could test positive. (For example, a low cut-off level could cause a positive result from consuming poppy seeds.) Conversely, a high cut-off level will result in more “false negatives,” and thus some users may go undetected. However, a high cut-off level lessens the likelihood of taking action against someone based on “passive” exposure, and for this reason SAMHSA’s guidelines set cut-off levels on the high side.
Want to learn more?
FYI Screening is fully integrated with eScreen to provide drug-screening services to employers nationwide. eScreen’s online management system is power-packed with every tool you need to hire and maintain a healthy, drug-free workplace.
Source: U.S. Department of Labor
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