Drug testing is an essential part of the hiring process for regulated sectors. Employers can conduct tests using urine, saliva, hair, and blood samples.
Tests look for certain drugs that impair an employee’s ability to do their job well. Testing can be done for cause or with reasonable suspicion, either triggered by direct observation or based on a documented pattern of unsafe work behavior.
Urine Tests
The most commonly used drug tests are those that analyze urine samples. Employers can perform urine tests pre-employment, as part of a conditional job offer, or after a workplace accident or injury. They can also test current employees when they reasonably suspect drugs or alcohol are causing safety issues.
A urine sample is sent to a laboratory for pre-employment drug testing—the most common tests screen for alcohol, amphetamines, benzodiazepines, cannabis, and cocaine. The test results are visually read and usually come back within a few days.
The immunoassay test used in most urine tests is relatively cost-effective and gives quick results. However, it can occasionally provide false positives. Thus, a confirmatory test is performed. This is more expensive, but it rarely produces false positives.
Urine tests can be administered at home or a professional lab; many medical insurance plans cover the costs. Before taking a urine test, disclose any over-the-counter or prescription medications you are taking, as they can affect the results. Once the results are available, the employer or laboratory will provide you with a copy. If the results show that you have used drugs or alcohol, the company will decide on disciplinary action. For example, the company may choose to terminate your employment if it is found that you violated its policy. Still, they may also offer you Employee Assistance Program (EAP) treatment or counseling.
Blood Tests
A blood test can screen for a much more comprehensive range of drugs than a urine test. During this type of test, a sample of your blood is taken by a licensed phlebotomist and sent to a lab for testing. Results can reveal the levels and types of drugs that were in your system at the time that the test was conducted. Blood tests can also check for drug residues in your body even after the effects of a drug have worn off.
Employers commonly use blood drug tests for law enforcement personnel, medical professionals, and other employees in safety-sensitive positions who must pass regular drug screenings. They may also conduct them based on reasonable suspicion of employee drug abuse or after an accident to determine whether an employee’s drug use caused the incident.
Blood drug tests are expensive and more invasive than urine and saliva testing. They have short detection windows and can be challenging to adulterate. Despite these drawbacks, some employers use them because they can detect drug use over a long period and screen for many different substances. Let the phlebotomist know your prescription medications so they don’t interfere with your test results. If your urine or blood test results are positive, a medical review officer (MRO) will contact you to discuss the chain of custody and any prescriptions that might explain the result.
Hair Tests
Employers that screen their employees for drugs do so to protect themselves from liability and safety issues. The most common pre-employment drug tests are urine, saliva, and hair. Companies in regulated industries like transportation, healthcare, and construction must adhere to strict regulations governing their workforce that require these tests.
A hair test for drugs measures the levels of specific drug metabolites in an employee’s hair. It can detect many substances, including marijuana, phencyclidine (PCP), cocaine, heroin, methamphetamine, and other synthetic drugs. Hair testing is more accurate than urine or blood tests as it can identify the presence of metabolites in the body for up to 90 days, whereas other test methods only detect recent usage.
Mouth swab tests for drug use are relatively newer yet still highly effective and quick to perform. This method is simple and quick to administer, with a sample consisting of an employee placing the mouth swab in their mouth until saturated. It is the quickest and most effortless test to run, with results coming back within a few minutes. However, it has the shortest detection window, only identifying drug usage for up to 72 hours before testing.
The accuracy of hair follicle tests depends on the length of the hair sample, treatment history (shampooing, bleaching, and chemically treating), and the type of hair used (white, black, or brown). Additionally, it is possible for a test to return inaccurate results when an individual has been exposed to environmental exposures.
Saliva Tests
Employers are interested in finding out if applicants and employees are using drugs, as drug abuse is costly to the business.
Saliva tests can detect certain types of drugs. They use a mouth swab to absorb saliva and then analyze the enzymes to identify whether any parent drug is present. They are less expensive and quicker than urine and blood tests. However, they have a shorter detection window and can only test for certain types of drugs.
For example, long-acting benzodiazepines like lorazepam and diazepam can remain in the body for up to 48 hours, while short-acting ones can only be detected for five days. In addition, these tests can also be inaccurate if the employer uses an instant saliva test kit rather than sending it to a lab for confirmation testing with gas or liquid chromatography.
Saliva tests can be administered to employees pre-employment, during a random or periodic screening program, during an accident investigation, or as part of a reasonable suspicion test. Lastly, they can be used to monitor the effectiveness of an employee’s drug treatment program and ensure that they continue to comply with their prescribed medications.
