The Maryland Medical Cannabis Commission issued an advisory late Friday "to notify patients and other stakeholders of potential lead contamination of cannabis liquids in vape cartridges following exposure to heat."
The warning comes as the commission is enacting new rules that will require heavy metal testing at the stage when companies are making products to be sold to the public. State-licensed cannabis growers have been required to test for metals since the medical program began in 2017.
The new testing rules were introduced "to correct an oversight of the original regulations," said Joy Strand, executive director of the commission. Drafted late last year, the proposed rules were open to public comment through the end of last month and took effect Friday.
"The proposed regulations still need to go through the established approval process, however, in the interest of public safety, and as an additional safeguard for quality products we are requiring the testing on the final vape cartridges to begin immediately," Strand said.
The commission began an investigation into lead in vape cartridges in "late March or early April" after learning of concerns in other states, she said.
Some patient advocates have been demanding for weeks that state regulators alert the public to the potential risk with lead in cannabis. When asked Wednesday about when the commission would notify the public about its investigation, Strand said, "What we learn from the investigation will determine our next steps."
Then, after 5 p.m. Friday, the commission issued its advisory.
"The results indicate that while lead is not present in Maryland vape cartridges at the time of product testing, lead may leach into the product from exposure to the heating coils with use, over time," the statement said. "Reports in other states and a small sample of used vape cartridges tested in Maryland indicate that lead may leach from metal heating coils into the cannabis liquid within the vape cartridge with use, over time."
Strand could not say "for sure" that the investigation is over.
"We felt it was in the best interest of public safety to take these steps today with what we know now," she said.
As it is with tobacco products, vaping is a common method of delivering medical marijuana.
Concerns about lead were sparked early last year by a study published by the Johns Hopkins Bloomberg School of Public Health that had found "potentially unsafe levels of lead, chromium, manganese and/or nickel" in several e-cigarette vaping devices, which are similar to those used for consuming cannabis. Worries escalated earlier this year when California's newly mandated heavy-metal testing detected lead in vape products.
With the new rules taking effect, Maryland is now among a few states that require two steps of tests for heavy metals in cannabis -- one at the growing stage and one at the processing stage when raw flower is infused into products ready for sale. California, which has permitted medical cannabis for 23 years, just implemented metals testing for processed products in January.
Several people in the industry say there is no cause for immediate concern.
"You haven't seen any heavy metals at the grow level" above safety limits, said Manoj Adusu of Quales LLC, one of the certified testers. "We haven't seen any heavy metals at the processing side. The only other source would be the vape pen."
In cheaply made metal cartridges -- as opposed to ceramic ones -- the heat that creates the vapor could cause lead to leach into the product, Adusu and other experts said.
When companies want to cut costs they may use "low quality vape cartridges" that can more easily release lead, he added.
He has not seen any evidence of that in Maryland.
Since Maryland's program began in late 2017, the state has required its five certified independent labs to test for heavy metals among numerous other elements in the marijuana flower cultivated by the state's 15 licensed growers.
However, state rules have not required the labs to look for lead and other metals as they test for other impurities in cannabis-infused products -- such as oils, waxes, ointments, capsules and vape cartridges -- that the state's 17 processors make and sell to dispensaries.
In addition to verifying the presence of cannabidiol (CBD) or tetrahydrocannabinol (THC), the ingredient that delivers a "high," labs test processed products to make sure they do not exceed safe levels for certain chemicals, molds, insects, hair or any "microbiological impurity," state rules say.
The processors fill vape cartridges with concentrated cannabis oil, then insert them into pen-shaped vapes that heat the drug into a vapor that users inhale.
Strand said the new rules require heavy-metal testing of cannabis oil after it has been sitting in vape cartridges. The commission's statement said it was notifying licensed processors and labs about the enhanced testing requirements for vape cartridges.
Adding heavy metals to that processing review is not complicated, but it will cost processors and laboratories more money. The typical cost for testing such samples is about $500 per batch or lot, according to state industry experts.
In the Maryland market's first year from Dec. 1, 2017 through Nov. 30, 2018, patients spent $96 million to purchase 729,309 cannabis-infused products and 10,800 pounds of flower, according to a commission report to the General Assembly.
Jeffrey C. Raber, CEO of The Werc Shop in Los Angeles, has been testing cannabis and consulting with marijuana companies for a decade. He said the Hopkins study and the initial findings from California's new tests have worried a national industry expected to reach $23 billion in sales in five years, according to a new market analysis by the Brightfield Group.
"Everyone has been scrambling," Raber said. "It's an issue, but people are trying to tackle it quickly."
Maryland has faced a similar situation before. When the state's industry first started in December 2017, growers detected contamination of the cutting blades used for harvesting crops with a cancer-causing heavy metal, officials said. But a fix was quickly implemented.
"We did find an issue with Chromium early on that was easily remediated by using different cleaning products and techniques," Strand said in an email. "It was from the stainless steel surfaces and tools used. No chromium contaminated products ever reached patients."
"Please be assured one of the main focuses of the Commission is patient safety," she added.
Various states have responded differently to lead contamination fears because they all are dealing with a drug that is still illegal under federal law, which classifies it, heroin and other substances as having "no currently accepted medical use and a high potential for abuse."
"Some states are requiring testing for cannabis products such as tinctures and edibles," said Julianne Nassif, director of environmental health for the Association of Public Health Laboratories. "But we are not aware of states requiring testing for the contribution of contamination that might come from vape pens."
Vape pens would be considered a medical device and would require oversight by the Food and Drug Administration, which has become "increasingly concerned with vaping" with nicotine devices, she said.
Mackie Barch, owner of the Culta dispensary in Baltimore's Federal Hill and chairman of the Maryland Wholesale Medical Cannabis Trade Association, said the processing stage's "multiple steps" are effective at detecting and removing contaminants as products are made.
Barch said reputable cartridge manufacturers produce safe products and that his company and others use ones made out of ceramic. Maryland's commission did not find any leaching in vape products that use ceramic components.
If cartridges are "made of crappy metals they can have toxic metals," he said.
Patient advocate Phil Ash wrote the only letter of public comment to state officials about the proposed regulations that raised public health concerns about patients.
He stated that the commission needs to go further and allow patients to test their own products. But Maryland only authorizes its certified labs to conduct such tests for growers and processors.
"This means that the patient's right to ensure that they have safe medicine has been removed," he wrote.