Modernizing aerosol
transportation regulations
The first patents for aerosols were issued in the 1920s,
but the first widespread use was during World War II,
where canisters filled with propellant and insecticide were
used to protect U.S. troops from malaria. The industry saw rapid
commercial growth during the 1950s that continues today, both
in the U.S. and globally. Aerosols offer a convenient and efficient
method to deliver a broad range of products including paints,
solvents, pesticides, food, personal care products and many others.
The aerosol industry has successfully evolved over the years
in response to regulatory challenges and changing consumer
expectations. The original aerosols were typically metal cans filled
with a mixture of flammable propellant and product. Over the
years, advances in aerosol technology have led to a wide variety
of propellant types, aerosol container materials, methods to dispense
and quality control; however, regulations have been slow to
change and are not harmonized globally. As a result, industry has
faced impediments to innovation, delays in getting new products
to the market and challenges in global distribution.
The Council on Safe Transportation of Hazardous Articles
(COSTHA) has worked in conjunction with other trade associations
to advocate for changes in both the domestic and international
regulations to better align the regulations with current
technology and harmonize regulations globally. Following are
highlights of some of the successes we have had and some challenges
that remain for the industry.
Hot water bath test
During the 1950s, the hot water bath test was developed in
response to concerns regarding the fire and safety hazards of the
new lightweight commercial aerosols. After almost 70 years, this
test remains the primary method to detect aerosol can leakage.
However, there are issues with the test, including the limitations
of manual leak detection on high speed lines, high energy
22 Spray October 2020
requirements and the large
footprints of equipment. In
addition, with some newer
technologies—such as bag-onvalve
(BOV) and additional
materials of construction, like
plastic containers—the test is
ineffective or not practical.
A provision was added to
the 2007 European Agreement
concerning the International
Carriage of Dangerous Goods by Road (ADR) that allowed alternatives
to the water bath test with the approval of a competent authority.
COSTHA later successfully advocated for recognition of
alternative testing methods at the UN Subcommittee of Experts
on the Transportation of Dangerous Goods. In 2012, COSTHA
petitioned the U.S. Dept. of Transportation Pipeline & Hazardous
Materials Administration (PHMSA) to expand authorization
for alternative methods to the water bath test. This resulted in
incorporation into the hazardous materials regulations in Title
49–Code of Federal Regulations (49 CFR) in 2014. PHMSA added
some additional alternatives in 2016 from the incorporation of
special permits, but work remains to be done to modernize and
harmonize testing methods.
I
nnovations necessitate regulatory updates
Restrictions on aerosol container design and authorized materials
of construction limit innovation domestically and internationally.
Regulations need to be updated to authorize additional designs
and materials of construction. In the U.S., industry needs to
petition for acceptance of flammable aerosols in plastic containers
as limited quantities, a provision that is already available for
road transportation in Europe and other contracting countries
to the ADR (European Agreement concerning the International
Carriage of Dangerous Goods by Road). The safety data compiled
relating to the transport and use of these innovative aerosol
containers further supports the amendments and authorization to
enhance global harmonization within our domestic regulations.
In the U.S., 49 CFR defines an aerosol as “an article consisting
of 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.” Internationally, there is no requirement to expel a liquid,
paste or powder, which then allows gas-only products to be classified
as aerosols. This difference puts U.S. manufacturers of these
products at a disadvantage in the global market.
PHMSA historically has authorized several of these gas-only
aerosol packages for use under the previous “Exemption” process,
Challenges & opportunities
Don Bossow
Senior Regulatory Advisor,
Council on Safe Transportation
of Hazardous Articles (COSTHA)