Written on: October 1, 2026 by Nicholas Georges
For years, the U.S. definition of an aerosol included a curious limitation that differed from international standards. Under the Hazardous Materials Regulation (HMR), the gas inside an aerosol container had to be used to expel a liquid, paste or powder. As a result, products designed to dispense only gas did not meet the definition of an aerosol and could not be transported under the same requirements as other aerosol products.
That technical distinction had practical and costly consequences. Gas-only aerosol products required a special permit for transportation, creating an additional regulatory burden for companies manufacturing, filling, packaging and shipping these products.
Fortunately, the Pipeline & Hazardous Materials Safety Administration (PHMSA) recently addressed this issue. On Aug. 4, PHMSA published its final rule, Hazardous Materials: Reducing Burdens on Domestic Aerosol Shippers, revising the definition of an “aerosol” in 49 CFR § 171.8 to include products that dispense gas without a liquid, paste, or powder.i The rule took effect on Sept. 3, 2026.
The updated definition is a welcome development for the aerosol industry, but it is hardly a new effort. Although the formal petition was filed in 2017, Industry had been working to address the outdated definition and better align U.S. requirements with international standards for years.
An aerosol is now defined as a non-refillable receptacle containing compressed, liquefied or dissolved gas, with or without a non-poisonous liquid, paste or powder, equipped with a self-closing release device. The contents can be discharged as foam, paste, liquid or gas. In practical terms, the revised definition recognizes gas-only aerosol products, making the U.S. regulatory framework more consistent with requirements used around the world.
For manufacturers, marketers and distributors of these products, that seemingly small change has meaningful implications.
Of course, the revised definition does not mean that every pressurized gas container is now considered an aerosol. Products must still meet the definition and comply with all applicable HMR requirements, including those related to packaging, marking, manufacturing and labeling. What has changed is the removal of an outdated definition that treated gas-only aerosol products differently based on a limitation that no longer reflected international standards or current product technology.
This is regulatory modernization in one of its simplest and most useful forms. By removing the requirement that an aerosol must contain a liquid, paste or powder to be expelled, PHMSA has eliminated an unnecessary distinction, created greater consistency with international standards and provided industry with greater flexibility.
It is a relatively small change in the Federal regulations, but for the companies that manufacture, fill, package and transport these products, small changes can make a meaningful difference.
There is also a broader lesson in this rulemaking for the aerosol industry. The updated definition demonstrates why we need to look toward the future and proactively identify opportunities to modernize the regulatory framework for aerosol products.
The change itself appears relatively straightforward, but the process required to achieve it was anything but.
The formal petition to revise the definition was filed in 2017. Nearly nine years later, the final rule was published. Nine years is a long time for a change that, at its core, aligns the U.S. definition more closely with an established international standard and removes an unnecessary regulatory distinction.
That timeline should not discourage industry from pursuing regulatory improvements. It should have the opposite effect.
As the aerosol products industry continues to evolve, Industry needs to identify and address where regulations no longer reflect technology, manufacturing practices, transportation realities or international standards.
Government rulemaking takes time. Petitions must be evaluated, proposals developed, comments considered, interagency reviews completed and final rules published. Even seemingly straightforward changes can take years to move through that process. Waiting until a regulatory problem becomes urgent is not an effective strategy.
As aerosol products, technologies, manufacturing processes and supply chains continue to evolve, Industry must look ahead and identify where existing regulations may no longer reflect current realities—or where they could create barriers for innovation. Identifying those issues early gives regulators and stakeholders the time necessary to understand the problem, develop appropriate solutions and work through the regulatory process.
The Household & Commercial Products Association (HCPA) takes this forward-looking approach to its work on behalf of the aerosol industry. That means considering not only the products manufactured and transported today, but also where Industry is headed and where existing regulations may create unnecessary barriers tomorrow.
To get involved in HCPA’s activities, please contact me at ngeorges@thehcpa.org. SPRAY
