A History of Refrigerants and Their Environmental Impact

When you look at modern air conditioning and refrigeration, it’s easy to take for granted that cold air just “happens.” But the truth is, the chemicals we’ve used as refrigerants have gone through a long and sometimes destructive history. Understanding this history isn’t just helpful in passing the EPA 608 Certification exam — it’s essential to know why the rules exist in the first place.

The Early Days: CFCs

In the mid-20th century, chlorofluorocarbons (CFCs) like R-11 and R-12 were everywhere. They were cheap, stable, and incredibly effective at moving heat, making them seem like the perfect refrigerant.

The problem? CFCs contained chlorine, and in the 1970s, scientists discovered that chlorine was tearing apart the Earth’s ozone layer. This invisible shield protects us from harmful UV radiation. Each chlorine atom could stay active in the atmosphere for over 100 years and destroy up to 100,000 ozone molecules.

The result was the infamous “ozone hole” over Antarctica. The world had to act.

The Montreal Protocol: A Global Turning Point

In 1987, the world came together and signed the Montreal Protocol — an international agreement to phase out ozone-depleting refrigerants.

• CFCs were banned first.

• Then came HCFCs (hydrochlorofluorocarbons), like R-22 and R-123. These contained hydrogen, which made them slightly less stable and less damaging. But they still carried an Ozone Depletion Potential (ODP).

Under the U.S. Clean Air Act of 1990, HCFCs are scheduled for a total phase-out by 2030.

The Rise (and Fall) of HFCs

After CFCs and HCFCs, the industry moved to HFCs (hydrofluorocarbons), like R-410A and R-32.

• Good news: They don’t contain chlorine, so ODP = 0.

• Bad news: They have massive Global Warming Potential (GWP).

For example:

• CO₂ has a GWP of 1.

• R-410A has a GWP of 2,088.

That means releasing just 1 pound of R-410A warms the planet as much as over 2,000 pounds of CO₂.

To tackle this, the Kigali Amendment (2019) to the Montreal Protocol set a plan to reduce HFC production by 85% by 2036.

The Future: HFOs

Enter HFOs (hydrofluoroolefins), like R-1234yf and R-454B.

• ODP = 0.

• GWP < 600 (dramatically lower than HFCs).

• More efficient, compatible with modern oils, and better for long-term use.

But there’s a tradeoff: HFOs are A2L refrigerants, meaning they are mildly flammable. This changes how technicians must handle, transport, and service systems.

Why This Matters for Technicians

Every refrigerant change in history came with new tools, new rules, and new responsibilities:

• CFCs → HCFCs: Start of environmental awareness.

• HCFCs → HFCs: The ozone problem was solved, and the climate problem was created.

• HFCs → HFOs: Low GWP, but new flammability challenges.

Your EPA 608 Certification ensures that you understand these transitions and handle refrigerants responsibly as a technician. The ultimate goal is to let the ozone layer heal while reducing climate impact for future generations.

Key Takeaway

Refrigerants aren’t just “fluids in the line” — they’re at the center of global environmental policy. The EPA 608 rules exist because the mishandled refrigerant can cause decades of damage to our atmosphere.

Pro Tip: Always consider whether a refrigerant has ODP or GWP issues on the exam. That distinction usually determines how it’s regulated.