What environmental agency oversees refrigerant regulations in the U.S.?

The Environmental Protection Agency (EPA) is the agency responsible for overseeing refrigerant regulations in the United States. This includes managing the use of specific refrigerants that can have harmful effects on the environment, particularly those that deplete the ozone layer or contribute to climate change. The EPA enforces regulations stemming from laws like the Clean Air Act, which specifically addresses air pollution and sets standards for the use and disposal of refrigerants. By establishing guidelines and requirements for the proper handling of refrigerants, the EPA plays a crucial role in protecting both public health and the environment. This is why the correct answer is the EPA as opposed to the other agencies listed, which have different areas of focus, such as workplace safety, consumer product safety, and energy policies.