When I had my 89 GTA in to have the a/c checked, I was told it was contaminated, and that just to have it checked it would cost $125 EPA hazmat fee, plus whatever else they could find. First off, how can you tell the system is contaminated just by looking at it? Does that fee sound right, or are they just looking for a way to gouge my wallet?
And to save one question from being asked, after what I found out about the tranny, I can very easily believe the a/c is either contaminated or a pisspoor conversion was attempted in the past. Actually, that would be the same thing, wouldnt it?

 

Ask them how they knew it was contaminated, and what it was contaminated with. They cannot tell it is contaminated by looking at it, they have to hook it up to a tester.

If they were going to recover the refrigerant to service the system, it would have been common practice to hook up a refrigerant identifier to the system, prior to hooking up recovery equipment. If the identifier reading didn't show pure r12, or pure r134a, the system could be contaminated for any of a number of reasons, such as:

1) There may be a mix of R12 and R134a. When you take a car with low freon charge, a moron, a can of R134a, and a charging hose, and mix them all together, it can cause this to happen. Mixing them is a very ignorant thing to do, but it doesn't stop lots of people from doing it.

2) Your system could have a hydrocarbon refrigerant in it. Depending on your state laws, this can be illegal. Most reputable shops will not have anything to do with this refrigerant, except possibly to remove and destroy it for you (for a charge)

3) Your system may have a blended refrigerant in it (freeze-12,freezone,hotshot,autofrost,KarKool, etc.) Since these are a blend of anywhere from 2 to 5 refrigerant components, they can really screw with a refrigerant identifier.

When refrigerants are improperly mixed inside an ac system, the resulting mixture is considered to be hazardous waste by the EPA. Any shop working on it must recovery it into a disposal cylinder, and have it sent to an incineration facility, or they are in violation of the law.

Your system could also be contaminated with air, moisture, wrong type of ac oil, etc. However, I don't think this would have been what they were talking about. This kind of contamination is removed by normal service procedures.