What Types of Drug Testing Can Employers Use?

Employers have several options when it comes to workplace drug testing. The right type of testing depends on the nature of the work, regulatory requirements, company policy, and the level of deterrence an employer wants to achieve.

Understanding the different types of drug testing helps employers build a program that supports safety, compliance, and fairness without unnecessary cost or disruption.

Pre-Employment Drug Testing

Pre-employment drug testing is one of the most common forms of workplace testing. It is typically conducted after a conditional job offer has been made and before the employee begins work.

This type of testing helps employers screen applicants and set expectations early. While not required in most industries, it is widely used to reduce risk and support hiring decisions.

Random Drug Testing

Random drug testing selects employees for testing at unpredictable intervals. Because employees do not know when testing will occur, random testing is one of the most effective deterrents against substance use in the workplace.

Random testing is required in certain regulated industries, such as DOT-covered positions. In non-regulated workplaces, it may be used when allowed by state law and outlined clearly in company policy.

Reasonable Suspicion Drug Testing

Reasonable suspicion testing is conducted when a trained supervisor observes behavior or signs that may indicate impairment. These observations must be documented and based on objective criteria, not personal opinions.

This type of testing is used to address immediate safety concerns and should follow a consistent, well-defined process.

Post-Accident Drug Testing

Post-accident drug testing may be conducted after a workplace incident or injury. Employers often use this type of testing to help determine whether substance use may have contributed to the incident.

Policies for post-accident testing should be carefully written to comply with OSHA guidelines and applicable state laws.

Return-to-Duty and Follow-Up Testing

Return-to-duty testing is used when an employee is allowed to return to work after a policy violation or rehabilitation process. Follow-up testing may occur over a defined period to ensure continued compliance.

These testing types are more common in regulated industries but may also be used in non-regulated workplaces as part of a structured policy.

Types of Drug Test Methods

In addition to testing timing, employers can choose from different testing methods, including:

• Urine drug testing, the most widely used method

• Oral fluid (saliva) testing, often used for its convenience and observed collection

• Hair testing, which may detect longer-term substance use

Each method has different detection windows, advantages, and limitations.

DOT vs. Non-DOT Drug Testing Options

DOT drug testing follows strict federal rules regarding testing types, substances, and procedures. Employers covered by DOT regulations must follow these requirements exactly.

Non-DOT drug testing allows more flexibility in testing methods and program design, as long as employer policies and state laws are followed.