GREENSBORO, N.C. — Remember when everyone was worried about poppyseeds making you fail a drug test? Turns out that there's some truth to that, but it can easily be determined false by the levels registered.

But now there are some concerns about CBD oil and drug tests, even though companies claimed it couldn't happen. In fact, it's so real companies are getting sued. 

RELATED: Can CBD Oil Help Relieve Your Daily Aches & Pains?

One of the suits involves Bianca Thurston and Coni Hass. They're currently suing Koi CBD. They say they failed drug tests because of the company's CBD product. Thurston even lost her job. Koi says they provide a high-quality product and that they're investigating these claims.

CBD products are supposed to contain little to no THC. But research suggests some of them have more of the compound than they advertise. A 2017 study found that 18 of 85 products all had THC levels possibly high enough to cause impairment or intoxication. 

RELATED: Navigating The Complex World Of CBD Products

You can check the product for a certificate of analysis. It shows the results of the company's testing for THC, CBD, and other contaminants. We spoke with the North Carolina-based Everything hemp store. They say they keep copies of COAs in their corporate offices and can send them out upon request. 

But in the interest of full disclosure, since the FDA isn't regulating CBD oil, there's no external guarantee that that COA is accurate. If you're going to use the products, just know there is some risk of failing a drug test.

NC Mom Says She Was Arrested In Her Own Home For Using Legal Hemp

Can CBD Oil Help You Get To Sleep At Night

RELATED: 'I'm A Healer Not A Dealer' | Hemp Dispensary Opens In The Triad