I have recently been conducting a lot of drug testing seminars for companies. The fairly new workers’ compensation drug testing standards have made employee drug testing even more popular. While this article originally ran seven or eight years ago, I thought it might be helpful again, given the recent resurgence in drug testing interest.

Ninety-seven percent of employees favor some form of drug testing in the workplace. Why? Consider that drug users in the workplace are:

Surprisingly, while employers use this valuable tool in their work environments, few know about the substances they are asking the medical provider to test for. Here are some answers to some commonly asked questions.

What drugs are typically tested for? There are many drugs that are looked for during drug testing, though most are five-panel tests that follow the Department of Transportation guidelines. These are amphetamines, cocaine, cannabis (marijuana), opiates (morphine and codeine), and phencyclidine hydrochloride (PCP).

How long after use can drugs be detected? Many factors influence how long a drug can be detected in the urine. These include the amount of drug taken, the frequency with which it is taken, the period of time from ingestion to collection of the sample and the cut-off threshold. The window of detection, or length of time, varies greatly from person to person. The following is a rough guideline only:

Can an employee test negative for a drug that has been taken recently? The cut-off threshold, or concentration, is the amount of drug present in urine that determines whether the result is positive. If the amount of drug in the urine is equal to or more than the cut-off threshold, the test results are positive. If the amount is less than the cut-off threshold, the test is reported as negative. Therefore, yes, indeed.

Do poppy seeds test positive for an opiate? Unlikely. Some types of poppy seeds used on bagels and other baked goods may cause positive test results for the opiate morphine—if you eat a phenomenal amount—so it is possible.

Can a person test positive for marijuana without smoking it? Passive inhalation, which is the involuntary breathing of secondhand smoke from others, can cause marijuana metabolites to be present in a person’s urine. The cut-off threshold, however, is such that passive inhalation will not produce a positive result.

Can an over-the-counter antihistamine cause a positive test? Taking an over-the-counter antihistamine will not cause a positive result for an amphetamine. iBi