Generally, most private employers have a fair amount of latitude in implementing drug testing as they see fit for their organization, unless they are subject to certain Federal regulations, such as the U.S. Department of Transportation’s (DOT) drug-testing rules for employees in safety-sensitive positions. However, Federal agencies conducting drug testing must follow standardized procedures established by the Substance Abuse and Mental Health Services Administration (SAMHSA), part of the U.S. Department of Health and Human Services (DHHS).

While private employers are not required to follow these guidelines, doing so can help them stay on safe legal ground. Court decisions have supported following these guidelines, and as a result, many employers choose to follow them. These Mandatory Guidelines for Federal Workplace Drug Testing (also called SAMHSA’s guidelines) include having a Medical Review Officer (MRO) evaluate tests. They also identify the five substances tested for in Federal drug-testing programs and require the use of drug labs certified by SAMHSA.

The most common method of drug testing, urinalysis, can be done at the workplace (at a health unit, for example), a doctor’s office or any other site selected by the employer. An employee or applicant provides a sample to be tested. Usually precautions are taken, such as putting blue dye in the toilet and turning off the water supply, to prevent adulteration or substitution of specimens so that collection can be completed in privacy without any direct visual observation by another person.

Under SAMHSA’s guidelines, once a sample is provided, it is sent to a certified laboratory. The accuracy of drug tests done by certified laboratories is very high, but this certification applies only to the five substances tested for in Federal drug-testing programs and alcohol.