Refrigeration is a staple of modern living—we use refrigerants in air conditioners, aerosol spray cans, and, well, refrigerators. But it turns out that the most popular refrigerants of the 20th century depleted the ozone and had high global warming potentials. In episode 21 of Speaking of Chemistry, Sophia Cai takes a look at the pros and cons of new refrigerants recently approved by the Environmental Protection Agency to be used as more environmentally friendly alternatives.