QUESTION: Who can legally buy refrigerant?
ANSWER: Under federal law, it is illegal to sell R-12 refrigerant to anyone who has not passed an EPA-required certification course on refrigerant recovery and recycling procedures. This applies to professional technicians as well as DIYers. Some states and municipalities also have their own “can ban” laws that prohibit the sale of R-12 in small disposable cans.
The federal certification requirement has been in place since 1993. It also requires all repair facilities that do air conditioning work (whether recharging or repairs) to have certified A/C technicians, and to own and use an EPA approved and Underwriters Laboratories (UL) certified R-12 recovery and recycling machine. No venting of any type of refrigerant is allowed under current rules (R-12 or R-134a).
Why ban the sale of R-12 to DIY customers? The EPA wants to discourage DIY customers (and noncertified technicians) from recharging leaking A/C systems that should be fixed. Refrigerant leaks can be found with an electronic leak detector, or by adding ultraviolet dye to the A/C system, driving the vehicle for a couple of days with the A/C on, and then shining a UV light on the A/C system components to reveal the leak. The dye leaves a telltale yellowish-green stain that glows under UV light.
The R-12 can ban is almost a moot point these days because R-12 has mostly disappeared from the market. Since its phase-out, supplies have become very limited and prices are high. R-12 was phased out because it contains chlorine. When R-12 is vented into the atmosphere, the molecules react with ozone high in the earth's atmosphere and destroy ozone faster than it can reform by natural processes. The ozone layer is important because it acts like a shield and blocks harmful ultraviolet radiation from the sun. Scientists say the ozone layer has thinned significantly and blame the loss on the release of man-made chloroflurocarbon (CFC) compounds such as R-12.
So what about R-134a, the new “ozone-safe” refrigerant that has been used in new vehicles since 1993-94? R-134a contains no chlorine, so it cannot harm the ozone layer. But R-134a is a “greenhouse gas” that retains heat and contributes to global warming. The debate now is whether R-134a poses an environmental hazard and should also be phased out. One alternative engineers are investigating is the use of carbon dioxide (CO2) as a refrigerant. It is nontoxic, won't harm the ozone layer and has a global warming potential rating of 1 compared to 1300 for R-134a. But CO2 (also called R-744) requires a complete redesign of the A/C system because it operates at extremely high pressures (over 1100 psi). A more likely replacement might be a refrigerant called R-152a, which has a global warming potential rating of 140, but operates at similar pressures to R-134a.
As for R-134a, you can legally sell it to anyone, whether they are a DIY customer or a professional technician, certified or not. Some municipalities may have their own laws that prohibit or restrict the sale of any refrigerant (R-12, R-134a or other alternative refrigerants) in small cans, but at the federal level, the small disposable cans are still legal (at least for now).