Originally Posted by leathermang

Ok.. should have done this way back..... TEX599... just look at my signature for references. If you read all of each of them ( not chain elongation ) you will be way ahead of the game...

This first one is the authorization to use pressure for leak checking and vent the nitrogen/r22...just as reference...

''Releases of CFCs or HCFCs that are not used as refrigerants. For instance, mixtures of nitrogen and R-22 that are used as holding charges or as leak test gases may be released.''
from:Complying With The Section 608 Refrigerant Recycling Rule | Ozone Layer Protection - Regulatory Programs | US EPA

''Technicians are required to pass an EPA-approved test given by an EPA-approved certifying organization to become certified under the mandatory program. Section 608 Technician Certification credentials do not expire.''
from: Complying With The Section 608 Refrigerant Recycling Rule | Ozone Layer Protection - Regulatory Programs | US EPA

This is an open book test.
It does not cost much.
It can be done over the internet including paying for it.

it allows you to buy R12 at many places that you do not even know carry it... in fact many times the ' first day on the job counter help' do not know they have it in stock... if you have your license in your pocket and ask the manager ' presto' !!!!! But typically ebay or CList is cheapest way to get it... I paid $18 for 12 oz of R134a a month ago ( for my Ford ) ... bummer, but means the old price difference is pretty small now...