Producers and processors may be used to keeping an eye on their inputs to ensure their products are safe from pesticides and heavy metals, but they may have to begin worrying about something they hadn’t considered before: rolling papers.
A new study out of SC Labs in California found that 11% of the rolling papers analyzed had pesticides or heavy metals above actionable limits in California, which would have caused many products to fail batch testing. And in blunt wraps and cellulose-based papers, the failure rates were even higher.
“About half of that 11% were gross contamination. They were so contaminated that the level of contamination could potentially cause an overall product batch to fail based on California’s criteria,” said SC Labs president JoshWurzer. “Of the cellulose-based rolling papers, two of the three had over 1,000 times the allowable limit of lead, so that was reaching a point where I said these are potentially a health hazard.”
According to Wurzer, several of his clients received testing failures on batches of pre-rolls in which the cannabis itself had passed testing, prompting the lab to look further into the issue and discovering the rolling papers contained “significant amounts of the pesticide chlorfenapyr,” a Category 1 pesticide in California.
“When we tested the pre-rolls made with that rolling paper, there was enough of it to fail the whole pre-roll batch,” he said. “That definitely concerned us.”
Wurzer said the lab bought “every permutation of rolling papers” it could and tested 118 types of rolling papers, blunt wraps and cellulose-based papers.
The results revealed that 13 of the 118 samples exceeded California’s limits for either pesticides or heavy metals. Pesticides were found in 16% of the samples with 5% coming in over actionable limits. Heavy metals were found in 90% of the papers, with 8% containing at least one metal in concentration above actionable limits.
Wurzer said the danger to consumers remains low since all plant-based products will uptake some heavy metals or pesticides. He compared it to mercury levels in fish, saying that people don’t stop eating fish because of the levels, though the quantity and type of fish consumed might be limited.
However, cannabis processors need to be aware of how all their inputs can affect their testing.
“Expect background contamination in any of these products for metals for sure,” said Wurzer. “A significant portion of rolling papers contain either enough pesticide residue or heavy metals that if I was a manufacturer of pre-rolled products, I would want to be much more cognizant of my rolling papers than I think a lot of people are.”
Wurzer was quick to point out that the study was a small batch and more research is necessary, adding that it is possible a “bad batch” of papers caused the results. But he also warned against using cellulose-based papers. All three cellulose papers tested by SC Labs contained lead, with two of the three having more than 1,000 times the allowable limit.
“As someone who doesn’t just study this stuff, but uses cannabis, I won’t be rolling any joints with cellulose papers,” he said.