All the products we sell containing refrigerant, are for EPA Certified Technicians. Purchases for resale do not require any certification; However, you are required to keep accurate records of all purchases made. If you purchase any items from us containing refrigerant, you are affirming one or the other! *Small cans of refrigerant for MVA's, containing 32 oz. or less, "DO NOT" require any certification. Safety Data Sheets listed are for reference purpose only and relate to the ASHRAE "R" number only. All sales are final. We do not accept returns on any refrigerant due to change of possession concerns and hazardous materials shipping requirements.