California Investigation Finds Contaminants in Rolling Papers

A recent investigation into Californian rolling papers found traces of heavy metals in nearly 90 percent of products and detectable amounts of pesticides in 16 percent of the samples. Five percent of the papers tested registered over the allowable action limits. The tests were carried out by the California branch of the SC Labs.


The investigation was initiated after several SC Labs customers' pre-rolled cannabis cigarettes (joints) failed compliance testing for the pesticide chlorpyrifos after the cannabis inside had already passed a pesticide screening test.

“As a consumer, I would be very wary of those products in particular – and until more data came back – I would say cellulose-based rolling papers as a category.” - Josh Wurzer

“All of these customers had pre-tested their plant material and it came up totally clean for all pesticides before rolling them into the joints and submitting them for this batch testing. So, obviously, everyone was a bit surprised and curious as to where the contamination came from,” Josh Wurzer, president and co-founder of SC Labs, told Analytical Cannabis.


Once it was discovered that the rolling papers were responsible for the positive tests, SC Labs decided to see if the prevalence of contaminants was widespread. They tested over 110 different rolling paper products available either online or in the Santa Cruz area for both pesticides and other contaminants like heavy metals. This included:

  • Hemp-based papers

  • Cellulose-based papers

  • Rice paper-based papers

  • Pre-rolled joints

  • Wraps

For consumers, the most important finding is that all three of the cellulose-based rolling papers contained significant amounts of lead, even if no detectable levels of pesticides were present. “The cellulose-based rolling papers came in thousands of times over the inhalable limit for lead, basically maxed out the calibration on our instrument,” Wurzer explained. “As a consumer, I would be very wary of those products in particular – and until more data came back – I would say cellulose-based rolling papers as a category.”


Meanwhile, approximately 22 percent of the wraps also contained levels of heavy metals above the action limits for California, but they were well below the levels found in the cellulose-based papers. Additionally, pesticides were detected in 58 percent of the wraps, but only 21 percent exceeded the state action limits. “I want to caution people to not be too alarmed over this report,” said Wurzer. “The takeaways that I have from this is that there are certain rolling paper categories that have much more contamination – or appear to have much more contamination based on this report – than others.”


“I’d treat it sort of like how we treat some types of fish that are known to have high levels of mercury. You just limit your intake as a consumer.”


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