GWP 101
It is important to note that the “P” in GWP stands for potential; a gas not released
HFC-152a is employed as a propellant in various aerosol
products, including dusters, hairsprays, deodorants, body sprays,
lubricants, insecticides and electronic cleaners, where it has been
very successful in helping formulators achieve local VOC limits
while still providing a high-performance product to the market.
HFC-152a is not currently employed in MDIs.
Balancing VOC content & global warming impact
HFC aerosol propellants are not classified as VOCs and do not
count toward VOC regulatory limits for consumer products. As
a result, their use often allows formulators to lower the VOC
content of their aerosol products, helping to improve local air
quality, reduce exposure-related health effects and meet local smog
abatement guidelines.
EPA data1 clearly demonstrates that the use of HFCs in aerosol
products has a minimal impact on global warming. Most aerosol
propellant applications around the globe use hydrocarbon propellants,
reserving HFC propellant use for applications with unique
performance goals.
As seen in Figure 1, the relative impact on global warming of all
HFCs employed in aerosol propellant applications represents only
0.16% of the impact of all GHGs on global warming.
Data from the EEA for the EU-28 countries and Iceland is
in agreement with the EPA data and indicates that HFC use in
aerosol propellant applications accounts for only 0.12% of global
warming2.
EPA data4 indicates that for HFCs in aerosol applications, 63%
of the GWP-weighted emissions are from non-MDI applications
and 37% are from MDI applications. Hence, the relative contribution
to global warming of HFCs in MDI and non-MDI aerosol
applications is 0.06% and 0.10 %, respectively. Since the 0.10%
figure includes all propellant HFCs, the impact on global warming
of HFC-152a alone is in reality less than 0.10%.
Given its extremely small contribution to global warming, it is
perhaps no surprise that there are currently no regulations limiting
the use of HFC-152a in aerosol products.
In a nutshell
The legacy of HFC aerosol propellants is one of reduced VOC and
enhanced air quality and should be considered with a view that
takes GWP into account as part of a larger equation. The GWP
value of a gas does not indicate the actual impact of that gas on
global warming: the relative impact on global warming is found by
multiplying the GWP value of the gas by its emissions on a mass
basis. Based on U.S. EPA and EEA data, the impact on global
warming of HFCs used in aerosol products represents only 0.1%
of the impact of all GHGs. This minimal impact on global warming—
combined with their value in lowering the VOC content
of aerosol products, cost effectiveness, high performance, high
solvency, low toxicity and chemical and thermal stability—render
the HFC propellants valuable components of modern day aerosol
products. Spray
REFERENCES
1U.S. EPA Report 430-R-19-001 (2019).
2Annual EU GHG Inventory 1990-2017 & Inventory Report 2019 (EEA).
3Ground-Level Ozone Basics, https://www.epa.gov/ground-level-ozone-pollution/
ground- level-ozone-basics (U.S. EPA) (2016).
4EPA-450-F-16-003 (2016).
36 Spray December 2019
into the atmosphere has no impact on global warming...
Figure 1: Relative Impact of Greenhouse Gases on Global Warming1