Analysis: Heavy Metals Frequently Identified in Unregulated CBD Products

Miami, FL: CBD-infused products commercially available in retail stores and online often contain heavy metals, such as lead, arsenic, and mercury, and typically contain less-than-advertised quantities of cannabidiol, according to data published in the journal The Science of the Total Environment

Investigators affiliated with the University of Miami School of Medicine and with the Ellipse Analytics Testing Lab in Denver assessed 516 CBD products for cannabidiol content as well as for the presence of heavy metal contaminants. Of these products, 121 products were intended for oral consumption.

Consistent with prior analyses of unregulated CBD products, many contained impurities and inaccurate labeling.

Of the CBD-infused edible products analyzed, 42 percent tested positive for the presence of lead, 37 percent tested positive for mercury, 28 percent tested positive for arsenic, and eight percent tested positive for cadmium. 

Over 40 percent of all of the products tested contained significant lower percentages of CBD than advertised on the products’ labeling. Among edible products only, 29 percent contained lower quantities of CBD than advertised.

“Low-level contamination of edible CBD products with heavy metals and phthalates is pervasive,” authors concluded. “There is substantial discrepancy between the product label claims for CBD potency and the amount measured in both edible and topical products, underscoring the need for tight regulations for CBD product label integrity to protect consumers.”

They added: “Given that the consumer demographic purchasing CBD products includes those afflicted with pain, insomnia, anxiety, and other health conditions, these findings could give consumers and medical practitioners hesitation about the benefits and potential harm of CBD use. If left unaddressed, these findings could lead to decline in consumer trust and public health concerns. CBD mistrust could lead to consumers and retailers abandoning this category of potentially efficacious medical therapies. … It is incumbent upon manufacturers to recognize the prevalence of misleading claims on labels, identify the sources of the discrepancies between label claims and measured CBD content, and improve label accuracy through a commitment to frequent and thorough independent testing procedures.”

Heavy metal contamination has also been identified in unregulated delta-8 THC vapor products. 

More than three years following the passage of federal legislation legalizing hemp production, the US Food and Drug Administration (FDA) has yet to promulgate rules regulating the marketing and sale of commercial products containing hemp-derived CBD or other cannabinoids. Survey data compiled by the National Consumers League previously determined that more than eight in ten US voters desire greater federal regulatory oversight over the labeling and marketing of commercially available CBD products.

Full text of the study, “Heavy metal and phthalate contamination and leveling integrity in a large sample of US commercially available cannabinoid (CBD) products,” appears in The Science of the Total Environment.