There are many different employment tests for drugs. Each test has different sensitivities and each company different cut off values for what is considered to be a positive or negative result. Most commonly, they test hair, sweat, urine or saliva. Blood tests are the least common, the most intrusive and most expensive, but are necessary to test for certain drugs.
The SAMHSA-5
The Substance Abuse and Mental Health Services Administration requires that employees of certain companies, such as commercial drivers, be tested for five categories of drugs, known as the SAMHSA-5 list of drugs. This could be considered a basic drug test. The five drugs classes include the cannabinoids such as hash and marijuana, cocaine including crack, amphetamines such as speed, phencyclidine, or PCP, and opiates such as heroin, morphine, fentanyl and opium.
Additional Drugs
Depending on the wishes of the employer or the specific drug company, testing for other drugs may be done as well. These include MDMA, or ecstasy; ethanol, or alcohol; barbiturates; methaqualone, or Quaaludes; benzodiazepines such as Valium and Xanax; propoxyphene, or Darvon; methadone; hydrocodone; inhalants such as toluene and xylene; LSD; tryptamines such as psilocybin in mushrooms; and phenethylamines such as mescaline, or MDE.
Validity of Urine Samples
Many companies test for countermeasures in the urine such as color, which is more clear than yellow if the urine is watered down. Other countermeasures in the urine for which tests are performed include temperature, a compound secreted by the kidneys called creatinine, the acidity and the density.
