Private employers are generally not required by law to have a drug-free workplace policy. But federal contractors and grantees, and safety-and-security-sensitive industries and positions generally are required to do so.

For example, the Drug-Free Workplace Act of 1988 is a federal statute that requires some federal contractors and all federal grantees (recipients of federal grant money) to agree to provide a drug-free workplace as a condition of receiving a contract or grant from a federal government agency. See 41 U.S.C. §8101.

There are also federal statutes designed to protect the basic civil rights of workers by setting limits on how far an employer can go in investigating and establishing consequences for employee drug use. These statutes include (1) The Americans with Disabilities Act of 1990 (ADA); (2) The Civil Rights Act of 1964; (3) The Family and Medical Leave Act of 1993 (FMLA); and (4) The National Labor Relations Act of 1935 (NLRA). And drug testing procedures such as collection of an employee’s urine sample may not run afoul of privacy laws.

Private employers may generally require a job applicant to take and pass a drug test as a condition of employment. The job applicant may refuse to take the test, but that will usually mean the employer will not offer the applicant a job. But the law in some states may only allow an employer to require a job applicant to take a drug test after the employer has made the applicant a job offer conditioned on passing the test.

Private employers generally may also require an employee to take a drug test—but only if the employer has reasonable suspicion that the employee is using illegal drugs or alcohol. This belief must be based on specific objective facts and reasonable inferences when any of the following conditions exist:

• Direct observation of drug use and/or the physical symptoms of being under the influence of drugs or alcohol.

• A pattern of abnormal conduct or erratic behavior.

• Arrest or conviction for a drug-related offense; or the identification of an employee as the focus of a criminal investigation into illegal drug possession, use, or trafficking.

• Information provided by reliable and credible sources or independently corroborated.

• Newly-discovered evidence that the employee has tampered with a previous drug test.

And some employees may be subject to random drug testing—based on workplace safety (such as operating heavy or dangerous equipment), handling sensitive or secret data, operating public transportation (bus driver), or being responsible for public safety (police officer).

Federal law and the law in many states allows employers to drug test employees involved in workplace accidents as part of the accident investigation.

Drug testing laws vary from state to state, and in some states drug testing laws are not fully developed and are unclear. For example, in some states in which marijuana is legal for medical or recreational use, employers may test job applicants or employees for the presence of the drug and make employment-related decisions based on the test results.

In Texas, private employers are not mandated by law to implement a drug-free workplace policy, except for federal contractors and grantees, as well as positions that are sensitive to safety and security. These employers must comply with the Drug-Free Workplace Act of 1988, which requires a drug-free workplace as a condition for receiving federal contracts or grants. Additionally, federal laws such as the ADA, Civil Rights Act of 1964, FMLA, and NLRA set boundaries on employee drug use investigations and consequences, ensuring protection of workers' civil rights and privacy. Texas employers can require job applicants to pass a drug test as a condition of employment, typically after making a conditional job offer. Employers may also require drug tests for current employees if there is reasonable suspicion of drug or alcohol use, based on specific objective facts. Certain employees may be subject to random drug testing due to the nature of their work, such as those in safety-sensitive roles or handling confidential information. Furthermore, federal and state laws permit drug testing after workplace accidents. It's important to note that drug testing laws can vary and may be complex in states where marijuana is legal for medical or recreational use.