- Bob Marley
- Jan 9, 2025
- 5 min read
An updated industry standardization handbook published by the federal government this month includes new guidelines on allowable moisture loss in cannabis—standards meant to ensure that patients and consumers aren’t sold packages containing less product than advertised.
The National Institute of Standards and Technology (NIST) added a variety of updates to its line of industry handbooks for 2025, including one that says products can lose up to 3 percent of their total weight as the result of moisture loss. Though marijuana remains illegal at the federal level, the move recognizes that some plant material may dry out during shipping or storage but that purchasers still deserve their full purchase.
Dozens of states are expected to adopt the new standard as their own, which will help steer enforcement efforts and respond to consumer complaints, said Charlie Rutherford, co-chair of the National Conference of Weights and Measures (NCWM) Cannabis Task Group.
NCWM members approved the change in July, and it took effect January 1 with the publication of the NIST’s new “Checking the Net Contents of Packaged Goods” handbook, also known as Handbook 133.
“It’s all a recognition, really, of wanting to make sure that patients and consumers are being treated fairly in their purchases,” Rutherford said of the cannabis-related changes in an interview with Marijuana Moment this week. Wholesale transactions between businesses would also be subject to the new guidelines.
All told, 24 states adopt and update their packaged goods standards to align with Handbook 133, according to a separate NIST document. Another 20 have similar laws or regulations “in force,” using the NIST standard as the “basis of adoption, but from an earlier year.” That means nearly all states are likely to eventually adhere to the new allowable moisture loss standard.
At a NCWM meeting beginning this weekend, the group is expected to focus on how various state agencies use the new standards to guide enforcement and regulatory consequences.
“There’s going to be a big discussion on how various agencies are going to regulate this,” Rutherford said, “and at what pace, what severity, what penalties—those kids of things.”
“Now that they have a weight that is pass or fail, essentially, they can do investigations of the underweight complaints that they receive,” he added.
NCWM members acknowledged in creating the new standard that “in the retail Cannabis trade, insufficient attention and guidance is given to moisture migration in or out of some Cannabis packaging,” noting in a meeting agenda from last year that “as a result, the contents of some Cannabis flower packaging have been found to be underweight, resulting in the patient/consumer paying for weight they are not actually receiving.”
In Oregon, for example, “underweight complaints are the #1 consumer complaint,” according to the agenda’s original justification for the proposal. “For the fairness and safety of Cannabis consumers,” it says, a weight variance “based on enforcement of acceptable moisture ranges needs to be established.”
“Some Cannabis is very susceptible to environmental conditions easily losing or gaining moisture with consequences impacting net quantity, degredation of active cannabinoids, and/or microbial proliferation depending on the situation,” the explanation said. “These are just some of the reasons there are many concerns and uncertainty surrounding the moisture allowance of Cannabis.”
The 3 percent number is not only consistent with moisture variances that apply to other materials but also aligns with California rules, the NCWM agenda document said. NIST is a technical advisor and nonvoting member of NCWM.
Rutherford told Marijuana Moment at the time of NCWM’s approval of the new guideline that the 3 percent moisture loss threshold in the new Handbook 133 is similar to that for other products, like flour or dry pasta, though the cannabis provision allows only moisture loss, not absorption of moisture that would increase net weight. “As written, there would be no limit to going over the declared weight of the package,” Rutherford said.
This past summer, the American Trade Association for Cannabis and Hemp (ATACH) applauded the change when it was approved.
“This work may come across as esoteric to the casual observer, but it is foundational and historic becaues it requires the federal government to recognize the determination of cannabis standards and regulation,” Michael Bronstein, the group’s president, said in a statement, “which will eventually form the background for national legalization and trade.”
“Like NCWM does for every other industry where products are sold by weight,” ATACH added, “regulators now have a standard which allows them to ensure that consumers are being treated fairly.”
As for fairness, Rutherford told Marijuana Moment in the previous interview that the 3 percent variance allowance “isn’t a free pass to package flower at 97.1% of the declared weight.”
He described the moisture loss allowance as an “established gray area” rather than a limit.
NCWM “expects zero deviation on weight,” Rutherford said, adding: “The ‘allowance’ or ‘gray area’ is taken in context during the package inspection. For instance, for a package inspected 2 weeks after packaging, losing a couple percent in weight while on the shelf could be viewed as allowable. On the other hand, if a package is a couple percent low moments after packaging, it would warrant further investigation. If a package is outside the allowance/gray, then a total stop sale could happen.”
Another NIST publication, Handbook 130, includes labeling standards for cannabis products, which were added in 2024. At its annual meeting the year before, NCWM approved two new cannabis items to the federal standards handbook—one establishing a definition for cannabis and another dealing with the “water activity” of bulk, unprocessed plant matter.
NCWM considered last year adding guidelines around a universal symbol for cannabis products but ultimately passed on the proposal. Some members who considered the proposal noted that members weren’t qualified to consider its health-related aspects. Several groups have pushed for a universal symbol for cannabis products in the past, but Rutherford told Marijuana Moment in July that the latest rejection meant the proposal was “permanently dead.”
Another item considered for potential action this past year had to do with what types of scales are appropriate for weighing cannabis products, although that matter wasn’t scheduled for a vote at last year’s meeting. Rutherford said in the recent interview that NCWM is expected to take up the issue later this month.
In 2022, NCWM advised that state regulators be empowered to start rulemaking to create standards for measuring potency of cannabis products. Members discussed plans for packaging and labeling requirements and “reasonable variations in levels of cannabinoid” content.
How to reliably test marijuana and hemp have increasingly become key issues nationally, resulting both from the legalization of hemp in 2018 and the growing number of states with legal marijuana markets.
NIST last year released a new report as part of a project designed to help testing laboratories ensure accuracy and precision in testing cannabis products. The report focused on determining cannabinoid content in plant material samples, which followed earlier reports on moisture content and certain toxins and heavy metals.
NIST also announced last year that it had begun selling a cannabis reference material aimed at helping testing laboratories more reliably determine the potency and purity of marijuana and hemp. It’s pricy, though, with 4.5 grams of the stuff on offer at the time for $783.
Lawmakers at the state and federal levels have also begun looking at standards for delta-8 THC, a psychoactive compound commonly derived from hemp products. Already many products sold as hemp meet the federal definition of marijuana. A NIST analysis last year found that the vast majority of smokable hemp product samples–about 93 percent—contained more than 0.3 percent THC.
As law enforcement works to better distinguish hemp and marijuana, separate federally funded research published last year detailed two new ways researchers say they’ve discovered to test samples.
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Photo courtesy of National Institute of Standards and Technology.
