Most employees and job applicants will be asked to take a drug test at least once in their careers. From the employer's perspective, illicit drug use by employees results in greater absenteeism, decreased productivity and other negative factors. Also, many employers enact pre-employment (and sometimes post-hiring) drug testing procedures to protect against liability for the actions of their workers.

This article covers the legality of both pre-employment and post-hiring screenings for illicit drug use.

Pre-Employment Drug Testing

With few exceptions, private employers may require new hires to pass a drug test as a condition of employment. Prospective employees have the right to decline drug screening, but such refusing screening usually means the applicant gives up the job offer. Unlike drug testing in the course of one's employment (more on that below), pre-employment drug testing doesn't have to be justified by safety considerations or other job-specific concerns beyond the desire for a drug-free workplace.

Union members may not be asked to participate in a pre-employment (or post-hiring) drug test unless such testing programs are negotiated and specifically addressed in union contracts.

Although the U.S. Constitution does not protect private-sector employees from what may be perceived by some as an invasion of privacy, some states have laws limiting employers' rights to subject employees (either current or prospective) to drug testing.

Drug Testing During Employment

Many states have laws that limit the conditions under which an employer may require drug screening of existing employees. Typically, employers must justify drug tests of current employees as a safety and/or business necessity or in response to suspicion of drug use. Generally, although it varies from state to state, employees may be screened for illicit drug use under the following circumstances:

• The employee's job poses a significant safety risk to others, or to him or herself
• The employee is enrolled in a drug rehabilitation program or has just completed such a program
• The employee was involved in a work-related incident where the use of drugs is suspected
• Management has a reasonable suspicion that a given employee has been using illicit drugs, based on behavior or physical evidence

State and federal regulations mandate that employees in certain professions submit to drug testing, including airline pilots and those using heavy machinery. If you're unsure about your occupation's drug testing requirements, contact the appropriate professional organization or an employment attorney.

Federal Employees

Passage of the Drug-Free Workplace Act of 1988 prompted mandatory drug testing guidelines for many federal employees (executive agencies, the uniformed services, and most federal contractors). Federal agencies conducting drug tests are required to follow procedures set forth by the Substance Abuse and Mental Health Services Administration (SAMHSA).

These guidelines mandate testing for amphetamines, cannabinoids (marijuana), cocaine, opiates (heroin, morphine) and phencyclidine (PCP), requiring evaluation by a Medical Review Officer.

Invasion of Privacy

Challenges to workplace drug testing policies on grounds that they violate employees' privacy have not been successful. But while drug testing itself usually does not violate an individual's rights, the manner in which the test was conducted (or its results utilized) may sometimes cross the line.

For example, the U.S. Supreme Court has held that positive drug test results may not be used in subsequent criminal cases without the consent of the employee. Also, a drug test may be challenged on constitutional grounds if the results are divulged indiscriminately, if the test is conducted in a way that disrespects the subject's privacy rights, or if drug testing is done excessively or otherwise inappropriately.

Medical Marijuana

At least 16 states have passed laws allowing the medicinal use of marijuana by patients whose physicians recommend it. But employers in those states are not required to provide a reasonable accommodation for medical marijuana users.

One of the legal reasons for this is that employers may still be held liable for any work-related injuries caused by an employee who tests positive for marijuana use, medical or not. Another reason is that certain employers (such as commercial transportation companies) must abide by federal regulations that require drug testing. The federal government does not recognize the legitimacy of medical marijuana.

As an employee, you can be fired for using medical marijuana even if you are not found to be under the influence of the drug during business hours.

State Drug Testing Laws

The following is a brief sampling of state drug testing policies:

• California: Employers awarded state contracts or grants must certify that they will provide a drug-free workplace (similar to the federal requirement); contractors also must provide a written policy to their employees
• Florida: State law requires that preference for state contracts be given to contractors who have implemented a drug-free workplace policy; employers with drug-free workplace policies receive a discount on workers' compensation premiums
• Illinois: No legislation concerning drug testing
• New York: No legislation concerning drug testing; random drug and alcohol testing of city bus drivers, police officers and corrections officers has been upheld by state courts
• Texas: Employers with more than 15 employees (and workers' compensation coverage) must adopt a workplace drug reduction policy of their own choosing

Learn More About Drug Testing at Work in Your State from a Local Attorney

An employment issue involving drug testing can be highly emotional. A lawyer can help you assert your rights by closely examining the details of your situation and the relevant laws. Contact a local employment attorney to learn how they can help keep your job and your privacy.