Under Section 608 of the Clean Air Act of 1990, it is illegal to remove Freon without proper certification. There are four levels of certification as of 2015: Type I, Type II, Type III and Universal certification.
Type I certification allows equipment technicians to work on small appliances. Small appliances are defined as equipment that produces five pounds or less of Freon. Technicians with Type II certification are allowed to service medium- and high-pressure appliances. Medium-pressure appliances use a refrigerant with a liquid saturation pressure between 45 and 170 pounds per square inch, while high-pressure appliances use a pressure of 170 to 355 pounds per square inch. Type III certification allows technicians to work on low-pressure appliances, which are defined as equipment that uses a liquid saturation pressure of 45 pounds per square inch or less. Universal certification means a person has received Type I, Type II and Type III certification.