Section 608 (together with Section 609, which covers motor vehicles) of the Clean Air Act serves as the main form of occupational licensure for technicians in the heating, ventilation, and air conditioning (HVAC) industry in the United States. The law requires that all persons who maintain, service, repair or dispose of appliances that contain regulated refrigerants be certified in proper refrigerant handling techniques. The regulatory program helps to minimize the release of refrigerants, and in particular ozone depleting refrigerants such as chlorofluorocarbons and hydrofluorocarbons, as well as other regulated refrigerants as determined by Section 612. The licensure program complies with the requirements under the Montreal Protocol. The Environmental Protection Agency (EPA) published implementing regulations at 40 CFR Part 82.

There are four categories of certification:

A technician with the required level of certification may also legally purchase regulated refrigerants. And technicians who violate the Clean Air Act provisions may be fined, lose their certification, and may be required to appear in Federal court.

In general, along with general enforcement provisions, section 608 manages the following regulatory requirements:

For Type I systems the main requirement is to remove 80% of the refrigerant if the appliance's compressor is not running and 90% if running and evacuate to a 4 inch Hg vacuum.

For Type II or Type III applications, the appliance must be evacuated to the following levels for device manufactured after November 15, 1993 in order to recover the refrigerant

Where pressure classification of the refrigerant is defined by the refrigerant's pressure at 104F as

For systems containing 50 lbs or more of refrigerant, for each service, the owner must be supplied with information of: