R134a is the most widely accepted alternative automotive refrigerant used to replace R12. There are other refrigerants: some of which may work, some of which don’t work, some of which will destroy your a/c system and some of which are dangerous. The problem with these so called “drop in replacements” is that to properly handle them you may need dedicated equipment to identify the gas and evacuate it for proper disposal. This can be very very expensive. On this website we are addressing only R134a and not other suggested “drop in” replacements. So to keep things simple and to avoid controversy and politics we have R134a. At this time you can still find R12, but, because it is no longer produced, availability is limited to current inventories and the price per pound is greater than R134a.