Vermont House Committee Drops Plan to Lift THC Limits From Cannabis Bill
The bill comes amid renewed national attention to the question of how high-potency cannabis products affect the developing adolescent brain, including research led by a UVM scientist.
A Vermont Senate bill that would have eliminated the state’s 30 percent THC cap on cannabis flower and raised the cap on solid concentrates emerged from House Government Operations and Military Affairs last week without those provisions, after testimony in February from public-health officials, school prevention coordinators, and a Vermont medical center warned against the potency increases.
S.278, an act relating to cannabis, passed the Senate on March 27 with provisions to remove the 30 percent THC concentration cap on cannabis flower, raise the cap on solid concentrates from 60 to 70 percent, cut the cannabis excise tax from 14 to 10 percent, and authorize cannabis delivery services. The version recommended by the House Government Operations and Military Affairs committee on May 13 contains none of those provisions.
What survives in the House committee’s recommended version is a smaller set of changes: doubling the per-package THC limit from 100 milligrams to 200 milligrams; doubling the personal possession and retail transaction limit from one ounce to two ounces; raising the hashish possession limit from 5 to 10 grams; cutting outdoor cultivator licensing fees roughly in half; establishing a two-year pilot for cannabis event permits; converting employee licenses from annual to biennial; repealing the integrated license type; and authorizing the Governor to enter interstate commercial cannabis compacts if federal law changes. The Joint Fiscal Office’s May 15 summary characterizes the bill as a set of “various changes related to the adult-use cannabis market, including creating a pilot program for cannabis event and delivery permits.”
The bill moved from Government Operations to House Ways and Means on May 13, was placed on the House Notice Calendar on May 18, and was referred to the House Committee on Appropriations on May 19. It remains in Appropriations.
The science context the committee heard
The bill comes amid renewed national attention to the question of how high-potency cannabis products affect the developing adolescent brain. A Scientific American article this month surveyed multiple studies on cannabis and teen brain development, including a 2021 study led by Matthew Albaugh, an assistant professor of psychiatry at the University of Vermont Larner College of Medicine.
Albaugh’s study, published in JAMA Psychiatry, followed nearly 800 adolescents whose brains were imaged before they used cannabis at an average age of 14 and again five years later. The study found that reported cannabis use was associated with accelerated cortical thinning in certain prefrontal areas — an association the researchers describe as dose-dependent. The cerebral cortex is the brain’s outermost layer and governs higher-order functions including learning, memory, problem-solving and emotion. Albaugh attributed the effect in part to synaptic pruning, the brain’s ongoing elimination of unused neural connections, which the study suggests accelerates with cannabis exposure. The study is observational, and the researchers note that other preexisting factors may contribute to the patterns observed.
The Scientific American article also summarized research associating adolescent cannabis use with several mental-health and cognitive risks, including psychotic and bipolar disorders, dependency, and impaired memory and cognition. The CDC says approximately three in 10 people who use cannabis have cannabis use disorder. Imperial College London neuroscientist Matthew Wall told Scientific American that modern cannabis products bear little resemblance to those available two decades ago, with some concentrates containing up to 95 percent THC compared with single-digit potency typical of cannabis flower in the early 2000s.
What the February 18 hearing put on the record
When S.278 was still in the Senate, the House Government Operations and Military Affairs committee held a joint hearing with the Senate Economic Development, Housing and General Affairs committee on February 18. The witness list spanned cannabis cultivators, retailers, industry advocates, the Cannabis Control Board, the commissioner of the Vermont Department of Health, a school prevention coordinator, and the planning director of Southwestern Vermont Medical Center.
Among the witnesses was Glauke Cooijmans, prevention coordinator at Mount Anthony Union Middle and High School in the Southwest Vermont Supervisory Union. Cooijmans wrote in her testimony that S.278’s potency and purchase-limit increases would “promote normalization of the use of cannabis in Vermont” and raise the risks associated with cannabis use across the community, including from higher-potency products.
She backed her position with Vermont Department of Health data from the 2023 Youth Risk Behavior Survey: 35 percent of Vermont high school students and 8 percent of middle school students have ever used cannabis. Twenty-two percent of high schoolers and 4 percent of middle schoolers reported past-30-day use. In her own district, those figures run higher — 41 percent ever-use among high schoolers and 23 percent past-30-day. Six percent of Vermont high schoolers report first trying cannabis before age 13; two percent of middle schoolers before age 11.
Cooijmans also pointed to Vermont Poison Control data showing cannabis-related calls involving Vermonters age 0 to 19 rose from 2 calls in 2012 to 26 calls in 2021, with the largest increase among 6-to-12-year-olds — driven, she said, by accidental ingestion of edible products. She described conversations with students who reported emergency room visits with cannabis-related symptoms including dissociation, paranoia and intense fear, often connected to use of high-potency “dab” pens containing concentrated THC wax.
Other witnesses at the joint hearing included James Pepper, chair of the Vermont Cannabis Control Board; Rick Hildebrant, commissioner of the Vermont Department of Health; and James Trimarchi, director of planning at Southwestern Vermont Medical Center, who presented to the committee on cannabis hyperemesis syndrome.
The industry argument that did not survive committee
The case for the Senate-passed potency provisions was made before the same joint hearing by Dave Silberman, director of the Vermont Cannabis Action Fund and co-owner of FLŌRA Cannabis, a licensed cannabis retailer in Middlebury.
“We support lifting the 60% potency cap,” Silberman wrote in his submission, adding that the Action Fund also backed eliminating the 30 percent cap on flower. Silberman’s organization frames Vermont’s potency limits as a competitive disadvantage that pushes consumers toward the unregulated market. He cited the 2019 tainted-vape crisis — in which the Centers for Disease Control and Prevention ultimately confirmed 68 deaths and more than 2,800 hospitalizations from illicit vape products — as evidence of the public-health risks of restricting the regulated market.
Both the 30 percent flower cap elimination and the 60-to-70 percent concentrate cap increase were among the Senate-passed provisions that did not appear in the House Government Operations committee’s recommended amendment two months later.
Vermont and Connecticut are the only two states with a 30 percent THC cap on cannabis flower, and Vermont is one of a small number of states that impose any percentage-based potency limits on inhalable cannabis products. Montana caps flower potency at 35 percent. The current Vermont caps were established when the state built its regulated adult-use market under Act 164 of 2020 and subsequent amendments.
Federal context
The bill comes as the federal regulatory landscape shifts. The Trump administration in late April moved to reclassify certain marijuana products from Schedule I to Schedule III under the federal Controlled Substances Act — a category designated for drugs with moderate to low potential for physical or psychological dependence.
The federal rule applies only to FDA-approved cannabis-derived drug products and marijuana subject to state medical marijuana licenses. State-regulated adult-use cannabis, which is the subject of S.278, remains federally classified as Schedule I. The reclassification also does not affect state-level potency limits, which remain matters of state law and regulation.
What’s next
S.278 is now in House Appropriations after earlier review by House Government Operations and Military Affairs and House Ways and Means. If the bill clears Appropriations, it would return to the House floor for final consideration. The Senate has already passed an earlier, more expansive version. Because the House version differs substantially from the Senate-passed bill, any final enacted version would likely require reconciliation between the two chambers.
Most provisions in the House committee’s recommended version are written to take effect July 1, 2026.
The Legislature has posted bill text, the Joint Fiscal Office fiscal note, and witness materials on its S.278 bill page.