A crucial, if little known, component of Colorado’s law legalizing recreational marijuana is scientific testing of the plants and products for potency and contaminants prior to sale. So prepare yourself for a real buzzkill: Analyses of different samples of marijuana circulating around the state reveal high levels of THC, low levels of CBD, along with some unwelcome impurities, including certain fungi, butane, and even heavy metals. Andy LaFrate, founder of a marijuana testing and research lab in Denver, Colo., presented his findings today at a meeting of the American Chemical Society.

THC, or tetrahydrocannabinol, is the psychoactive chemical within the plant that causes the high, while CBD, or cannabidiol, is the chemical aspect that offers therapeutic benefits. While THC stimulates the brain in such a way to release dopamine, it also interferes with the hippocampus, a memory-making part of the brain. The National Institute on Drug Abuse notes that “high doses of marijuana can produce a temporary psychotic reaction (involving hallucinations and paranoia) in some users, and using marijuana can worsen the course of illness in patients with schizophrenia.” LaFrate’s tests of pot samples revealed high levels of THC, yet little to non-existent levels of CBD.

Unnaturally High Potency?

“We’ve seen a big increase in marijuana potency compared to where it was 20 to 30 years ago,” LaFrate said from his lab, Charas Scientific. “I would say the average potency of marijuana has probably increased by a factor of at least three.” Additionally, the tests uncovered fungi or bacterial contaminates, along with butane in some cases and even heavy metals in others.

While Colorado law requires retail marijuana and infused product be tested for both potency and contaminants, the Marijuana Enforcement Division delayed implementation of its testing program in order to allow enough scientific labs to be certified. Only now is science beginning to catch up with the burgeoning retail industry. According to LaFrate, the division will select a group of producers to participate in mandatory beta testing in order to make sure any contaminant limits they set will be reasonable and achievable by industry producers.

Colorado will require all retail marijuana to be tested for five species of microbial contaminants, LaFrate explained in a blog post, including both bacteria (STEC E. coli and Salmonella) and mold (three species of the fungus Aspergillus). “When you’re dealing with something like marijuana that’s been under prohibition for the last 80 years, scientific testing really gives the government and consumers confidence that this is something that’s safe,” LaFrate said. He adds that it is only a matter of time before testing is also required for medical marijuana in Colorado.

For more information, watch the American Chemical Society/YouTube video below: