Drug and Alcohol Testing

Organizations use drug and alcohol testing to determine whether an employee (or prospective employee) is under the influence of alcohol or specific drugs. The drugs included in the test are illegal drugs such as cocaine, marijuana, PCP, and methamphetamines and commonly abused legal drugs such amphetamines, barbiturates, and opiates.

Drug and alcohol tests are also used to confirm that employees are in compliance with organizational substance abuse policies. Many organizations are drug-free workplaces. They have policies and programs that prohibit drug and alcohol use in the workplace. Testing is used to ensure compliance with their policy.

The primary reasons employers use testing are safety and productivity. A variety of statistics connect employee alcohol and drug use with higher absenteeism, lower productivity, higher medical insurance claims, and increased frequency of on-the-job accidents and injuries. Evidence also connects increased employee theft, property damage, and security issues to workplace drug use. All of these represent significant costs to organizations that can be reduced by preventing drug and alcohol abuse among employees.

There are legal reasons to conduct drug and alcohol testing. Many employers are required under state or federal regulations to have policies prohibiting drug use among employees. These laws are often justified under the umbrella of public safety. For example, truck drivers and railroad workers are covered by Department of Transportation regulations that require drug and alcohol testing.

Employers who choose to implement a drug and alcohol testing program typically analyze the costs and benefits of the program. Employers argue that the benefits of preventing drug and alcohol abuse significantly outweigh the costs of a testing program. Preventing one serious accident is usually enough to justify the cost of the program. In the case of government-mandated testing, the cost of testing is considered a normal cost of business.

Drug testing programs are intended to affect the behavior of applicants and employees. Many employers advertise their testing program to job applicants to deter current drug users from applying or being hired. By educating current employees about the testing program, employers hope to discourage employees from using prohibited drugs or abusing alcohol.

Testing identifies potential policy violations. Organizations can then remove the offenders from the workplace or put them into a rehabilitation program. In many programs, the testing policies explicitly encourage employees who may have chemical dependency problems to seek appropriate treatment. Treatment or counseling options may be offered in lieu of disciplinary action.

Many employers offer an employee assistance program (EAP) that provides free and confidential counseling to employees and their immediate family members. An EAP allows employees to get professional help with drug or alcohol problems before getting caught in a testing program.

Employers also use testing to reduce potential liability. For example, if an employee’s drug or alcohol use could cause harm or injury, the organization may use testing to reduce that risk. In the event of on-the-job accidents, testing may identify a contributing cause of the accident. Under workers’ compensation law in some states, a positive drug test may reduce or eliminate the employer’s financial liability for a work-related injury.

Drug and Alcohol Testing Methods

Several methods are used to test employees for drug use:

  • Urine test: The most common test is a urine test. Urine samples are easy to collect and cost-effective to test. The disadvantage of urine testing is that a variety of substances and equipment are available for the sole purpose of cheating on the test.
  • Blood test: Blood tests for drugs are more accurate than urine tests. It would be virtually impossible to cheat on a blood test. However, a blood test is considered by many to be invasive and is considerably more expensive than a urine test.
  • Hair test: Hair retains detectable residue of drugs. The hair test is considered to be very accurate. It does not necessarily prove that someone was under the influence at the time of the test. The hair sample test is expensive. Although not invasive, hair sample testing is not common. It would, however, be difficult to cheat on a hair test if the sample were collected properly.
  • Sweat test: A relatively new test uses a sweat sample. The individual wears a patch on his or her skin for several days. The patch collects a sample of sweat, which is then analyzed for the chemical residue and active ingredients of various drugs. The patch cannot be reattached if it is removed, therefore limiting tampering or cheating.
  • Saliva test: Saliva can be tested for both drugs and alcohol. This test is accurate, samples for it are easy to collect, and cheating on the test is difficult, but it is not currently a common testing method.
  • Alcohol test: Testing for alcohol levels is usually performed by one of two methods: a breathalyzer test or a blood test. Both tests are considered accurate and are difficult to dispute when done properly.

A positive test is one in which the presence of drugs or alcohol is detected and confirmed above a defined threshold level. Threshold levels are carefully set to prevent false positives or positives owing to incidental exposure. A negative test is one in which no prohibited substance is detected in the sample above the threshold levels. A negative test does not conclusively determine that the individual is not a drug user. It only verifies that at the time of the test, the person was not considered under the influence.

Drug and Alcohol Testing Protocols

For all tests, it is critical that specific protocols are followed to maintain integrity in the process. For tests mandated by federal law, the federal regulations require specific procedures. For any program, applicable state and federal laws should be reviewed prior to developing the program. To avoid challenges to test results, it is extremely important for employers and testing facilities to strictly follow all required protocols. Some typical protocols are described below.

Samples must be obtained under controlled conditions to limit opportunities for tampering or cheating. For example, when a urine specimen is collected, the toilet used should have dyed water in both the bowl and the tank to prevent sample dilution. Fresh water should not be available in the room where the sample is collected. The temperature of the specimen must be checked to verify there was no substitution or dilution.

Samples must follow a strict chain-of-custody process. The chain of custody documents who handled the specimen and the times and dates of every change in custody. The custody documentation must be retained with each specimen. This ensures the sample is not tampered with at any step in the process.

Tests should be done only by certified labs that have proven they meet or exceed all applicable regulations, levels of accuracy, and staff competence.

Equipment should be tested regularly with known samples. Positive results must be verified using alternative testing equipment to ensure accuracy.

The laboratory must have a medical review officer (MRO) review all positive tests. The primary responsibility of the MRO is to receive, review, and interpret all test results before they are reported to the employer. The MRO would answer any questions regarding the accuracy of the test. The MRO must be a qualified licensed physician.

Types of Alcohol And Drug Testing

Employer testing programs typically include the following types of drug and/or alcohol testing:

  • Preemploment: Testing done on job applicants prior to hire. Preemployment testing is normally done after a contingent job offer is extended. The offer can be rescinded if the applicant tests positive. Applicants sign an acknowledgment that they are aware of the preemployment testing requirements and that any job offer is contingent on passing a drug test.
  • Random: Testing that is done on an unscheduled basis. Employee drug testing can occur at any time to anyone covered by the program. This approach adds an element of surprise and would presumably discourage drug use. Random testing programs select a specified number of employee names for testing at regular intervals.
  • Postaccident: Testing that is done immediately following any work-related accident. The policy should describe specifically what conditions trigger a test— for example, requiring a test after any accident that involves a personal injury or property damage.
  • Reasonable suspicion: Provides for an employee to be tested if there is reason to believe that the employee is under the influence or unfit for duty. Those with the authority to require a test must be trained to recognize what would justify reasonable suspicion. Difficulty walking, talking, or performing simple tasks; smells of alcohol or marijuana; or witnesses who observed use of prohibited substances are examples of behaviors and circumstances that might trigger a reasonable suspicion test.
  • Scheduled: This is testing conducted at regular or scheduled intervals. It is common in industries that for safety or security reasons test employees on a regular basis. It is also used for follow-up testing as part of last-chance agreements. In those cases, the employee has previously tested positive and as a condition of employment is subject to ongoing tests.
  • Baseline: Testing done at the start or implementation of a drug program. Employers can use baseline testing to identify drug users and then either terminate them or provide substance abuse counseling.

Arguments against Drug and Alcohol Testing

Workplace drug and alcohol programs are criticized for a variety of reasons. Common arguments are based on invasion of employee privacy and accusations of inaccurate tests resulting in false positives.

The invasion of privacy argument is based on the premise that employers should not have the right to dictate off-work behavior, particularly behavior that does not affect the employer. This argument is easier to accept for off-duty behavior that clearly has no connection to work performance or the employer. In some situations, employees’ off-duty activities and affiliations may even be protected by law. For example, under federal law employees cannot be discriminated against based on their religion or union membership.

However, in the case of drugs or alcohol, an employer would argue that a test showing the active ingredients of illegal drugs or the presence of alcohol over a certain limit does affect the person on the job. In the case of dangerous jobs, this can be a very compelling argument. Employers carefully word their policies to prohibit employees from being under the influence of drugs or alcohol at work. The presence of the prohibited substances in the employee’s blood or urine while working would therefore be a violation of company policy. It would not matter where or when the drug or alcohol was ingested. The employer has an interest in the employee’s off-duty behavior because it affects on-duty behavior and job performance.

Other Issues and Concerns

Recently, local and state laws have been proposed— and, in some jurisdictions, have passed—that legalize the use of marijuana for medical reasons. The Supreme Court has ruled that local laws do not supersede federal laws or regulations regarding the use of marijuana. This has allowed employers to continue to treat marijuana as an illegal substance even in areas where its use is legal under certain circumstances.

Because drug testing involves personal medical information, the use and release of test results may fall under federal privacy laws. Most employer policies already treat drug testing information as private and highly confidential. Employers should be even more careful in today’s legal environment to ensure that strict confidentiality is maintained.

Training is key to the successful implementation of any drug testing program. Employees need to be aware of how the program works and to have some level of confidence in the process. Employee education about the effects of drugs and alcohol in the workplace is also critical to acceptance of the program. Managers need to be trained in how to recognize signs of drug use. At the same time, they must be cautioned against making a diagnosis. That should be left to trained professionals.

Cheating on drug tests is a serious concern; however, it is hard to measure. Numerous Web sites and other resources claim to offer proven methods or products for beating drug tests. Product offerings include clean urine specimens, masking agents, and even prosthetic devices to deliver a clean sample while under observation. As long as there are drug users, there will be a market for ways to cheat. It is important for employers to be aware of cheating methods and to design procedures that minimize the opportunity for cheating.

Employers can expect periodic claims that a result was a false positive. The usual allegation is that something other than inappropriate drug use caused a positive result. In most cases, the threshold level set for a positive result will virtually eliminate false positives for secondary or dietary exposures to similar substances. The issue of addressing allegations of a false positive test is best left to the MRO. This person is well qualified to determine if there is any possibility of an inaccurate result.

Drug and alcohol testing is very complex. Laws vary from state to state. The technology for testing has dramatically changed over time. In addition, the ingenuity of cheaters continuously improves. An employer implementing a testing program should obtain competent technical, medical, and legal advice.


  1. de Bernardo, M. A., & Pedro, G. M. (2005). Guide to state and federal drug testing laws (13th ed.). Vienna, VA: Institute for a Drug-Free Workplace. Smith, S. (2004). What every employer should know about drug testing in the workplace. Occupational Hazards, 66(8), 45-47.
  2. United States Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Division of Workplace Programs. http://workplace.samhsa.gov/

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