But that may change. On Friday, the U.S. Environmental Protection Agency announced that supermarkets in all 50 states had promised to try to control these gases by voluntarily signing up for the agency's GreenChill program.
The program's aim is to help supermarkets reduce the amount of refrigerant emissions, greenhouse gas pollution and ozone-depleting gases escaping from the stores.
Several California-based stores and nationally recognized chains have signed up for the program, including Stater Bros., Lucky's, Whole Foods and Target.
Supermarkets require large amounts of electricity to run lights, air conditioning and cash registers. But it's the chemicals used to keep freezers, refrigerators and produce counters cool that are the largest threats.
These chemicals, known as hydrofluorocarbons, or HFCs, are thousands of times more potent greenhouse gases than carbon dioxide.
And regulators and climate scientists worry unintended leakage of these chemicals could have drastic effects on climate.
"If you have a lot of piping, if you have a lot of joints, the probability of leaking is greater," Karim Amrane, vice president of regulation and research at the Air-Conditioning, Heating and Refrigeration Institute -- a trade group representing equipment manufacturers -- told Climate Wire.
In 2007, the EPA created GreenChill to address these concerns. They now have 7,000 members, or about 20 percent of all supermarkets in the country, registered as partners.
According to the EPA website, GreenChill partners' refrigerant emissions are 50 percent lower than the industry average. The agency predicts that if every supermarket signed up and reduced their emissions by just 12 percent, the atmosphere would be spared 22 million metric tons of carbon dioxide and 240 tons of ozone-depleting substances every year.
It would also save the industry more than $100 million in refrigerant costs every year.
"GreenChill is a great example of how businesses and government can work together to protect people's health and the environment," said Gina McCarthy, assistant administrator for EPA's Office of Air and Radiation. "GreenChill capitalizes on industry's drive for innovation by providing a forum for technology advances and financial savings."
Story courtesy of our media partners at California Watch (A Project of the Center for Investigative Reporting)