New Climate-Friendly

Motor Vehicle Air 

Conditioning Refrigerants

Alternative Refrigerants

HFO-1234yf (R-1234yf)

HFO-1234yf is a refrigerant being introduced 

by many automobile manufacturers. There are 

cars on the road today using this alternative. 

HFO-1234yf is mildly flammable, but can be 

used safely.

Carbon Dioxide (CO2, R-744) 

CO2 is a high pressure refrigerant being 

considered by automobile manufacturers. 

CO2 systems operate at 5 to 10 times higher 

pressure than other MVAC systems. 

HFC-152a (R-152a) 

HFC-152a is a refrigerant that may be pursued 

in the future. HFC-152a is flammable, but can 

be used safely.

Environmental Impacts of MVAC Refrigerants

Refrigerant Global Warming 

Potential (GWP) Ozone Depleting?

CFC-12 10,900 Yes

HFC-134a 1,430 No

HFC-152a 124 No

HFO-1234yf 4 No

CO2 (R-744) 1 No

*GWP values are from the Intergovernmental Panel on Climate Change 

Fourth Assessment Report: Climate Change 2007

EPA’s Ozone Layer Protection Website

http://www.epa.gov/ozone/strathome.html

Learn More about CAA Section 609 

and How to Become 609 Certified

http://www.epa.gov/ozone/title6/609/

EPA’s SNAP Program

http://www.epa.gov/ozone/snap/

430-F-13-041

September 2013

Disclaimer: EPA does not endorse any particular 

company or its products.
Protecting the Ozone Layer 

and Climate System

In the past your car was cooled by 

chlorofluorocarbon (CFC)-12, a substance 

that destroys the stratospheric ozone layer 

that shields the Earth from the sun’s harmful 

ultraviolet radiation. Automobile manufacturers 

transitioned to the non-ozone depleting alternative 

hydrofluorocarbon (HFC)-134a in the mid-1990s. 

HFC-134a, like its predecessor, is a potent 

greenhouse gas that contributes to climate change. 

Today, automobile manufacturers are beginning 

the transition to new, climate-friendly alternative 

refrigerants.

Section 609 of the Clean Air Act (CAA) establishes 

requirements to prevent the release of refrigerant 

during the servicing of motor vehicle air 

conditioning (MVAC) systems through proper 

servicing procedures. 

Transitioning to Alternative 

Refrigerants

EPA’s Significant New Alternatives Policy (SNAP) 

Program ensures the smooth transition to 

alternatives that pose lower overall risk to human 

health and the environment. Under SNAP, EPA 

recently listed three low global warming potential 

(GWP) MVAC refrigerants as acceptable subject 

to use conditions: hydrofluoroolefin (HFO)-1234yf, 

carbon dioxide, and HFC-152a. None of these 

alternatives deplete the ozone layer and all have 

significantly lower impacts to the climate system 

than CFC-12 or HFC-134a.

In the United States and globally, many automobile 

manufacturers are transitioning to these low GWP 

alternatives. It is important for both consumers 

and technicians to be aware of these alternative 

refrigerants, their properties, and proper servicing 

procedures.

SAMPLE LABELS LOCATED UNDER VEHICLE HOOD

HFO-1234yf

Refrigerant Type

Relevant

Standards 

Total

Charge

Amount 

Use Caution Flammable Requires Certification

Refrigerant Type

Relevant

Standards 

Total

Charge

Amount 

Use Caution Requires Certification

Lubricant

Type

Lubricant

Type

Copyright © SAE International. Reprinted with permission.

Clean Air Act Requirements

AS REQUIRED BY FEDERAL LAW

• MVAC systems may only be serviced for consideration 

(payment or bartering) by technicians trained and 

certified under CAA Section 609.

• It is illegal for any person to knowingly release or vent 

refrigerants (except CO2) during service, maintenance, 

repair and disposal. Such actions pose a risk to human 

health and the environment.

• Technicians must use certified service equipment 

designed for recovery only or recovery, recycling and 

recharging of MVACs.

• MVAC systems, service equipment and containers 

have unique fittings for each refrigerant to prevent the 

dangerous mixing of refrigerants. An adapter should not 

be used to convert a fitting.

• Refrigerant must be properly recycled before recharging 

it into an MVAC system. 

• Hydrocarbons are not approved for use in MVAC systems. 

MVAC Servicing Best Practices

SERVICING TIPS

• Locate and repair leaks before topping off a system. 

Failing to repair leaks may result in MVAC system 

damage or failure.

• Do not add more refrigerant than necessary. This 

can cause system damage and decrease system 

performance.

• Never mix refrigerants or use a refrigerant not 

intended for an MVAC system. Mixing refrigerants, 

even accidentally, can lead to higher than expected 

system pressures, component and system damage, 

diagnostic errors and hazards to human health and 

the environment.

• Beware of contaminated refrigerants. Consider 

purchasing certified refrigerant identification 

equipment. 

• Read and comply with all specifications on refrigerant 

containers, vehicle manufacturers’ manuals, and 

lubricants. 

• Do not replace system components with salvaged 

parts, or parts from a system meant for another 

refrigerant.

MAKE SAFETY A PRIORITY 

• Review and practice safety procedures and use 

protective equipment.

• When servicing MVACs, particularly systems with 

HFO-1234yf and HFC-152a, avoid sparks or flames in 

the work area.

• Wear safety glasses and insulated gloves, and avoid 

direct contact of refrigerant with skin.

• Work in a well-ventilated area. Acute exposure to any 

refrigerant can lead to harm to your personal safety 

and health, including asphyxiation. 

CO2