Eating Poppy-Seed Bagels and Other Excuses for Failing Workplace Drug Tests

​HR professionals have undoubtedly heard a range of claims from job candidates explaining their positive drug-test results.

Todd Shoulberg, executive vice president of medical information services at background screening firm ClearStar, recently debunked the most common excuses in a discussion with SHRM Online.

[SHRM members-only online discussion platform: SHRM Connect]

SHRM Online: What is the most common explanation candidates give for a positive drug test?

Shoulberg: Secondhand marijuana inhalation is the one that comes up more than anything else.

When a person tests positive for marijuana, believe it or not, it is never that person who smoked the drug [according to him or her]. Even though millions of people smoke marijuana, it's never that person with the positive test. It's always that person's best friend, girlfriend, husband, wife. They were at a concert. They were in a car where someone smoked the drug. They were at a party where someone smoked around them. It is never them—they got it in their system secondhand.

To be clear: This is not possible. That's because of cutoff levels. You're allowed so much of every drug in your system before you actually register a positive drug test. For example, marijuana has an initial cutoff level of 50 nanograms. You would have to be locked in a phone booth for hours [with someone smoking marijuana] to inhale enough marijuana smoke to register over the cutoff level for a positive. Someone sitting next to you smoking marijuana will not be enough to register a positive.

SHRM Online: What about the infamous 'I ate a poppy-seed bagel' excuse?

Shoulberg: Just like marijuana, there are cutoff levels preventing [a positive test result]. The cutoff levels for opiates, which poppy seeds fall under, is set at 2,000 nanograms. Many years ago, that number was 300. The reason for the jump is that most of the positives came from foods or some other legal use of poppy seeds. Because of that, the federal standards were changed. Today, you would have to eat dozens and dozens of poppy-seed bagels and muffins before a test to get close to the threshold. [A positive test result] is still possible if the laboratory is not using the current federal standards.

SHRM Online: Can over-the-counter (OTC) drugs cause false positives?

Shoulberg: Yes, but that's why testing programs have a two-step process, and it's important to understand the process to debunk this excuse. Hundreds of medications and supplements out there can cause false positives. Someone will test positive, usually for marijuana, and they will claim that an OTC product, diet pills, or supplement caused the false positive.

All drug testing through certified laboratories is broken down into EMIT screens and gas chromatography-mass spectrometry [GC/MS] confirmation tests. The EMIT screen is the initial screen. That's a quick test that separates negatives from [presumed positives] and undetermined results flagged for further testing. OTC products can potentially cause a false positive on the EMIT screen. But people don't realize that once you fail an EMIT screen, the laboratory will automatically move that specimen to the GC/MS test. That test is the gold standard. It is 99.9999 percent accurate. It can distinguish between illegal drugs and diet pills or any other OTC product.

[Visit SHRM's resource page on background checks.]