By: Bob Richard
With so much focus over the years on harmonizing dangerous goods regulations, one commodity that can definitely benefit from a focused review is aerosols. This is particularly a concern relative to U.S. regulations, where the definition for aerosols is not aligned with the international definition, causing confusion among shippers and carriers.
In §171.8 of the Hazardous Materials Regulations (HMR) the term “Aerosol” is defined as “any non-refillable receptacle containing a gas compressed, liquefied or dissolved under pressure, the sole purpose of which is to expel a non-poisonous (other than a Division 6.1 Packing Group III material) liquid, paste, or powder and fitted with a self-closing release device allowing the contents to be ejected by the gas.”
This definition is inconsistent with the definition of an aerosol found in the United Nations (UN) Model Regulations, the International Maritime Dangerous Goods (IMDG) Code, International Civil Aviation Organization Technical Instructions on the Safe Transport of Dangerous Goods by Air (ICAO TI), and the Regulations governing European Road Transport (ADR). The main difference: International regulations do not prohibit an aerosol container from being filled and dispersing a gas. This disharmony leads to a number of reclassification and marking problems for shippers and carriers alike.
U.S. regulators have taken the position that an aerosol container filled with pure butane, for instance, should not be allowed to be reclassed under the proper shipping name “Aerosol.” U.S. regulators have indicated on numerous occasions that this would compromise safety and, in particular, emergency response efforts by masking the true hazards of the product contained in the aerosol receptacle. Nevertheless, there really are no standards related to how much propellant gas can be contained to expel the liquid, powder or paste.
Industry experts report some products on the market have upwards of 95% propellant gas which in many cases, consists of Isobutane that is highly flammable. However, there also are many consumer products that pose very little risk in transportation such as air dusters and refrigerant gases (e.g. 1,1,1,2-Tetrafluoroethane (R-134a)) that could certainly benefit from harmonization and a fresh look at the HMR requirements. In the U.S., the more restrictive definition requires 1,1,1,2-Tetrafluoroethane (R-134a) to be offered as UN3159 1,1,1,2-Tetrafluoroethane unless otherwise authorized by a special permit. These products must be transported under special permits that are cumbersome to acquire and put to use.
The current HMR aerosol definition in the U.S. has been in place for more than 25 years, and was developed because regulators were concerned with aerosol containers filled completely with gas. An aerosol is a product that generally is intended to disperse a liquid, powder or paste. However, today there are a number of products that disperse pure gas from an aerosol can such as those used for HVAC replenishment, tire repair, sports and camping products and office products such as air dusters. These products can only be transported under a special permit issued by the Department of Transportation. The special permits applications take months for approval and are cumbersome to prepare. Additionally, they expire, requiring the holder to reapply periodically. This process is burdensome for both the regulator and the regulated industry.
The Pipeline and Hazardous Materials Safety Administration (PHMSA) recently awarded a contract to conduct a comprehensive risk analysis to determine if harmonizing the HMR to the UNMR would maintain the current level of safety during transportation. If HMR harmonization with the UNMR definition of aerosols maintains the current level of safety, then harmonization will reduce the burden on international and domestic shippers of aerosols and improve US commerce with its trading partners. If HMR harmonization does not maintain the current level of safety, this information can be shared with US trading partners to help improve the safety of foreign transportation of aerosols and to potentially propose amendments to the UNMR definition.
Providing harmonized requirements for aerosols would allow many products to be marked, labeled, and documented for transport in the U.S. as they would be for international transportation, thus reducing the cost and burden of remarking and re-documenting shipments destined for distribution in other countries.
In conclusion, providing harmonized requirements for aerosols would reduce reclassification and marking problems for shipments destined for distribution in other countries, and simplify the transportation process for shippers and carriers alike.