Study Finds 90% of Rolling Papers Contain Heavy Metals

An analysis by California’s SC Laboratories Inc. of 101 rolling papers found at least one heavy metal in 90 percent of the papers tested with 8 percent containing at least one heavy metal in “concentrations above the allowable limits” in the state for inhalable cannabis products.

Lead was the most commonly detected heavy metal in the products “by a considerable margin,” the report says.

Pesticides were detected in 16 percent of the samples with 5 percent containing levels over the allowable limits. In all, 11 percent of the 118 total rolling papers included in the study “would fail above the action limits for inhalable products” in the state.

The study included 70 rolling papers, 25 pre-rolled cones, 20 wraps, and three cellulose-based papers. Of the rolling papers and cones, just one each exceeded California action limits for heavy metals, while eight of the wraps – 40 percent of those tested – exceeded state limits. All three of the cellulose papers tested exceeded action limits.

For pesticides, none of the rolling papers or cellulose-based papers tested exceeded action limits, and just one of the 20 cones tested exceeded the limits. However, four of the 19 wraps tested 0 21 percent – exceeded state limits.

The researchers conclude that “it is not surprising to find a prevalence of heavy metals detected in the rolling paper products and should not be considered alarming on its own;” the study, however, demonstrated “there is a wide range of concentrations of metals contamination in these products from a relatively low level to grossly contaminated.”

“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,” SC Laboratories President and Co-founder Josh Wurzer said in the report, meaning it is safe to assume that rolling papers combined with ‘clean’ cannabis would not cause a compliance failure under California rules.

The products used for the study were purchased from Amazon and various retailers in Santa Cruz.