The United States Environmental Protection Agency (EPA) has required that all persons handling refrigerants should be certified. If you are not certified you can't legally buy refrigerants.
EPA-Approved Section 608 certification is needed to service building air conditioning and refrigeration systems. With 608 certification, you can purchase any refrigerant in containers greater than 20 pounds.
Coyne College offers EPA testing at scheduled times thruout the year as well as a study guides, and a seminar. To register visit Student Accounts at the bursar window, or call them at 1-800-999-5220 ext:8054.
Try the following study links to help you prepare:
Free Practice Exams