Does CBD cause a positive on a workplace drug test?

Joel Smithwick, MD

Occupational-Environmental Medicine

CBD products are increasingly available and claim to help with everything from daily aches and pains to seizure prevention and more. These products aren’t regulated by the Food and Drug Administration, which can make it hard to know just how effective they are or even what ingredients they contain. Even as CBD use becomes more widespread, employees might be concerned about whether using CBD could cause a positive workplace drug test.

Occupational and environmental medicine specialist Joel Smithwick, MD, explained the uses of CBD and how it relates to workplace drug testing.

What is CBD?

“CBD, or cannabidiol, is just one of many compounds found in the cannabis plant,” Dr. Smithwick said. “Most people know about THC (tetrahydrocannabinol), the psychoactive ingredient in marijuana that actually produces the high the drug is most famous for. CBD supplement products contain a low amount of THC, and therefore do not cause a ‘high’.”

Hemp, which CBD supplements are derived from, is considered any part of a Cannabis sativa plant that contains no more than 0.3% THC. To be considered marijuana, the same plant would have a higher concentration of THC.

For decades, even hemp was considered a federally recognized controlled substance, which kept businesses and individuals from being able to legally own or work with the plant. This changed in 2018, when hemp was removed from the Controlled Substances Act. This means that if a CBD supplement comes from hemp, it’s effectively legal.

Can CBD still cause a high if it’s heated?

“There is evidence that heating CBD in supplements – think of using it in e-cigarettes, like vaping – will chemically transform it into THC,” said Dr. Smithwick. “In which case, CBD in e-cigarettes can be considered a sort of precursor to THC.”

Vaping CBD products can result in THC entering your system, even if you don’t feel a ‘high’ as a result.

Even internal use of basic CBD products, such as the ingestion of CBD chocolates or oils or touching your mouth or eyes after using CBD-containing skin products, can also result in your body taking in trace amounts of THC.

Does workplace drug testing pick up use of CBD products?

“Labs that test for drug use using a urine screen have extremely precise analyzers,” said Dr. Smithwick. “The machines they use for analysis can detect drugs in the part-per-billion range, which is like putting a drop of dye into a semi-tanker truck’s worth of water and still being able to detect it.”

Because the trace amount of THC found in CBD products is still the same THC chemical that found in smoking or using marijuana, this can cause a positive workplace drug test for THC.

Since use of CBD products is likely to cause a positive result in workplace drug testing for THC, use of those products should be avoided by those who are looking for a negative drug test.