British Columbia’s cannabis secretariat released the results of a study conducted on some 20 cannabis flower samples seized from six grey-market stores in Vancouver earlier this month.

The study, conducted with the B.C. Centre for Disease Control and the National Collaborating Centre for Environmental Health, found that only three of the 20 samples tested would have been approved for consumption and sale in the legal market. Nine contained pesticide residues and elevated levels of heavy metals. “Unacceptable levels” of bacteria and fungi were also found.

The study included tests from two cannabis cultivation facilities and found evidence of up to 41 pesticides at an unlicensed grow op compared to six at a licensed facility.

But the study shouldn’t be taken as an indication that all illicit weed is more contaminated—or less safe to consume—than legal weed. As the study itself points out, pesticides are ubiquitous in the environment and the sample size of weed tested is not big enough to draw definitive conclusions.

Legal weed has come a long way from the days of melting vape pens and massive product recalls for moldy and pesticide-laced cannabis. But walk into any legal retailer and it’s not unusual to still find yourself purchasing weed that was packaged six months earlier—and shows all the signs when smoked (i.e. black ash) that it wasn’t flushed properly.

“Flushing” is the process to clean cannabis of pesticides and fertilizers used in the growing process. It involves using only water to grow plants in the two to three weeks before the curing process. What’s on the legal market is largely mass-produced. And in the rush to get products to market, it’s not unusual for large producers to short-circuit the growing process—or speed it up. Which is why all the buzz these days is from small producers trying to differentiate themselves by growing small batches.

The B.C. secretariat’s analysis didn’t include recent pesticide results from licensed producers, but did include data from samples taken in 2018 in the early days of legalization. That found pesticide contamination in eight of 63 legal samples studied. How quickly we forget.

However, the real story from B.C.’s study may be THC content found in illicit versus legal weed. Turns out legal weed is way stronger, on average. That may or may not be a good thing depending on your personal use.

Another noteworthy wrinkle in the data is that moisture content in illicit weed is much higher than what’s allowed by federal regs. A common complaint of legal weed is that it’s too dry.