Random Drug Testing: How to Do It Fairly and Effectively

Random testing is one of the most effective deterrents because no one knows when their next test will be. But it only works, and only holds up to challenges, if it is truly random and applied the same way to everyone.

What makes testing random

• Every person in the pool has an equal chance of being selected every time.
• People selected once stay in the pool, so they can be picked again. This keeps testing unpredictable.
• Selection is done by a neutral method, such as a computer random number generator, not by a supervisor choosing names.

How to run a random selection

1. Keep an up-to-date list of everyone in the testing pool.
2. Decide how often you select and how many people each time.
3. Use a random number generator or spreadsheet function to pick names, and save a record of each draw.
4. Notify selected people and test them promptly, ideally within an hour or two, so there is no time to prepare.
5. Vary the day and time of testing.

How often to test

• Employers often set an annual rate, for example selecting enough tests each year to equal a set percentage of the workforce. Check any industry rules that apply.
• Sober living homes often test randomly about once a week. See our sober living policy checklist.
• Treatment programs set frequency by level of care.

Keeping it fair

• Put the random testing policy in writing and have everyone acknowledge it.
• Use the same test, collection steps and consequences for everyone.
• Treat refusals and tampered samples as described in the policy. See spotting fake samples.
• Confirm preliminary positives with a lab before taking action.
• Keep selection records and results confidential.

Keep supplies on hand

Random testing only works if you can test the moment someone is selected. Keep enough cups for at least a month or two. See buying drug tests in bulk.

Frequently asked questions

How do you pick people for random drug testing?

Use a neutral method, like a computer random number generator, where everyone has an equal chance each time.

Can someone be randomly tested twice in a row?

Yes. In a true random program, people stay in the pool after being tested.

How often should random testing happen?

It depends on your program. Sober living homes often test weekly; employers set an annual rate.

How quickly should someone be tested after selection?

As soon as possible, ideally within an hour or two of notification.

Related guides

• How to write a sober living drug testing policy
• How to spot a diluted or fake urine sample
• Instant drug tests vs. lab tests

Instant urine tests give preliminary results. Confirm any preliminary positive with a laboratory test (such as GC/MS) before taking action. Always follow the package insert.