When Is Drug and Alcohol Testing Performed?

by | Jun 18, 2015

Drug and alcohol testing has become an accepted thing in most workplaces, although there are several states in the country that limit an employer’s ability to test employees. The DOT also mandates only a limited range of drugs that can be screened for with these tests. Nevertheless, most employees are familiar with the process, at least with pre-employment screening. However, there are numerous other instances when tests are used today. What are these?


The most obvious type of drug and alcohol testing is during the pre-employment phase. Most employers have moved to a dual interview/drug test model that ensures that they are not hiring individuals with existing addiction or substance abuse problems. Essentially, if the interview goes well and you pass the drug test, you have a good chance of being hired.

Reasonable Suspicion

Reasonable suspicion testing is performed when a supervisor or manager has probable cause to think that you or another employee might be under the influence of drugs or alcohol at work. In DOT companies, supervisors must go through reasonable suspicion training before they can refer employees for drug and alcohol testing based on probable cause.


If you’ve been involved in an accident at work that caused injuries, damage, or harm to a customer, you can bet you’ll be required to submit to drug and alcohol testing. If the results come back positive, you will be censured, up to and including termination, and could possibly face legal charges.


Random drug testing is performed on a specific percentage of employees in business each year. The actual percentage tested varies depending on whether the employer is a DOT company or a non-DOT company.

Periodic Testing

Periodic drug and alcohol testing differ from random testing in that it’s applied to all employees within a business, and is usually scheduled ahead of time, rather than being completely random.


Return-to-duty testing happens if you have tested positive during another drug and alcohol testing period and were suspended as a result. You will have to get a substance abuse evaluation by a SAP that will provide education, treatment, and follow-up testing.  When you return to work, you will be required to take periodic, ongoing tests for up to 12 months.

There are many other times when drug and alcohol testing is performed, all depending on the specific industry and situation. Rehabilitation testing, follow-up testing and blanket testing are just a few of the other types in use today.

The information on this page may have changed since we first published it. We give great legal advice, but this page (and the rest of our site) is for informational use only and is no substitute for actual legal advice. If you’d like to establish an attorney-client relationship, reach out to us and we’ll tell you how we can make it official. Sending us an email or reading this page alone doesn’t mean we represent you.

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