Was built for R12, can be converted to R134a.
The original installed refrigrant was R12.
1993 and before it is R-12, 1994 and later its R-134a
A 1994 Buick Regal Custom uses 134a refrigerant, not freon.
R134a
R-134a
R134a
CA law does not prohibit freon in general. It prohibits R-12 type freon. You need to convert your AC system to R-134 freon, which costs about $35 in parts, and can be done at home if you have the mechanical training. R-134 freon is legal to purchase without a license.
Would have been built for R12, can be converted to R134a.
One type of freon that you can use on a 1990 Ford Econoline is Four Seasons R12 Refrigerant Oil. The canisters cost close to $10 each.
It came with R12 Freon. As R12 is cost prohibitive, have the unit converted to R134a refrigerant or a similar substitute.
Would have been built for R12, can be converted to R134a.
Originally R-12 - should be converted to R134A