The Challenge of Shifting to Lower Global Warming Potential Chemicals

Meghan McGinley

Share this post

Jul 2, 2020

It’s been nearly three and a half years since 197 countries agreed to the Kigali Amendment to the Montreal Protocol, a 30-year old treaty that banned ozone-depleting substances. The amendment pledged to a phasing down of high global warming potential (GWP) chemicals known as hydrofluorocarbons (HFCs) that are used in cooling equipment and fire suppressants. While HFCs comprise a small percentage of greenhouse gases, they can have more than a thousand times the heat-trapping impact of carbon dioxide. This is great news for the environment, but also poses a challenge because it increases its flammability, requiring more fire and life safety precautions. Additionally, the U.S. has not ratified the Amendment, and there is growing concern that a global phase-down in the production of HFCs will negatively impact the supply chains that typically rely on these chemicals, including the U.S. Army.

Why it is Challenging to use Low GWP chemicals?

As the world moves toward lower GWP options in applications including refrigeration, air conditioning and fire suppression, new challenges are being uncovered. Many of the alternative refrigerants, though having much lower GWP, are more flammable than the chemicals they are replacing. In most cases, this isn’t an issue for commercial or industrial applications.

This is, however, a critical issue for the U.S. military, who have vastly different requirements from commercial applications. Using low GWP chemicals in air conditioning units in the cars we drive is vastly different from a military vehicle being deployed in enemy territory. We can exit the vehicle in the case of a fire, but that’s not an option for military personnel during combat. For that reason and others, there is little to no tolerance for flammability risks.

To demonstrate this, we teamed up with the Army Research Laboratory to perform live fire testing on one refrigerant being widely used in commercial vehicle air conditioning units. This chemical has a very low GWP and is considered mildly flammable. However, when tested in a mock-up of an Army vehicle air conditioning system under a military-style threat, the result was a sustained fire event of over two minutes. These results demonstrated why it is necessary to thoroughly evaluate alternative technologies before transitioning them to the field. Without a thorough evaluation of chemical properties and performance, the health and safety of military personnel are put at risk.

Moving Forward

While a global shift to using low GWP refrigerants and fire suppressants is a huge step forward for us environmentally, there is still much work to be done. The environmental regulatory landscape is difficult to navigate, made more complex by the lack of clarity on how it applies to the U.S., which has not ratified the Kigali Agreement. Even so, the U.S. will see major disruptions to their supply chain, particularly in regard to the military, which may not be able to use some low GWP chemicals.

Before making the shift to low GWP chemicals, it will be critical for industries and the military to conduct thorough research and testing to ensure their safe application. Policymakers, manufacturers and researchers around the globe will need to work together to ensure alternatives are carefully evaluated before transitioning to the technologies we rely on, with the ultimate goal of minimizing our impact on global warming and climate change.