Lab Analysis: Some Rolling Papers Contain Unwanted Contaminants

Santa Cruz, CA: Some rolling paper products used by the manufacturers of pre-rolled cannabis cigarettes possess detectable levels of contaminants, including pesticides and heavy metals, according to a laboratory analysis performed by the California-based testing company SC Labs.

Of the 101 products assessed by the lab, eight percent tested positive for potentially dangerous levels of heavy metals, including lead, cadmium, and mercury, while five percent of samples tested positive for the presence of pesticides at levels above those allowable under California law.

While the analysis did not identify any products by brand name, a summary of the study in reported that the products with “very high levels of contamination” typically were “cellulose-based papers – the transparent, gummy papers sold as ‘clear’ papers in smoke shops.” Some “flavored blunt wraps” and so-called “natural hemp-based wraps” also contained detectable levels heavy metals. By contrast, no traditional rolling paper products tested positive for elevated levels of contaminants.

The analysis concluded: “While 11 percent of the rolling papers in this study would fail above the action limits for inhalable products in California, it should be noted that the paper constitutes only a fraction of the overall mass of a cannabis pre roll product. Although the ratio of the mass of paper to cannabis flower varies within pre-roll products depending on a number of factors, it is safe to assume that rolling paper products that fail near the action limit would most likely not cause a compliance failure when combined with ‘clean’ cannabis.”

Consequently, SC Labs President Josh Wurzer told Forbes that, despite the study’s results, most cannabis consumers have little reason to be concerned. He stated, “[T]he findings of the study don’t support too much alarm; this certainly isn’t a, ‘Raise the alarm bells now, we have to stop and test all papers.'”

Full text of the study, “Rolling papers tested for heavy metals and pesticides,” is available from SC Labs.