R134A has the same effect towards the ozone as R12 so it's illegal to vent into the air.

The legal method is to use have an a/c shop remove the refrigerant, or to use a rather expensive refrigerant recovery machine. An illegal, but semi-environmental approach, is to pull a vacuum on an empty recovery cylinder, then immerse it in a salt and ice bath and connect it to the system.

When we had our home a/c unit serviced by a licensed service company recommended by a local ac supply house, the tech didn't even have a recovery set in his work van.

You really need to stop huffing the nitrogen at FailureStone. That stuff isn't a drug, its for filling the tires.

If R134a was the same badness for the environment as R12... Then why are the "canned air" spray-duster cans sold at every office supply place filled with the SAME STUFF and designed to be vented directly when used? Tetrafloroethane 3,3,1 is the mix, IIRC. Answer me that one, hmm? A basic product doing exactly what you say is illegal... thanks for playing.

so-called "mandatory recovery" of R134a is designed to reduce the amount of refrigerant that a shop needs to purchase, by capturing and saving for re-use whatever they can from a customer's vehicle. They still have the equipment from the old R12 days (which was bad for the environment) so they might as well use it.

Home A/C systems and refrigerators use R22, which is being phased out for a new formula that I can't remember the name of. Some R22 systems are compatible with R134a, but it varies. It wouldn't surprise me that a tech might not have a recovery system in their truck, many times the customer's system has already leaked out anyway and that is why it failed. My undergrad college had an old building that they (seriously) had to wheel in a 4 foot tank of R22 about once every 4 months to recharge the system.

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This website explains requirements for recovery, reclamation, and recycling of automotive refrigerants:
http://www.epa.gov/ozone/title6/609/index.html

Dusting sprays use R-152a as a propellant.

R134a does have the same damaging effects of r12, the difference is that R12 sticks around for a REALLY long time(I forget how long), and r134a sticks around for something like 17 years instead of 100 with r12(for example, the numbers are somewhere on the correct magnitude, but not precise, but I can't easily find the numbers right now).

Hyrocarbon refrigerants break down in the atmosphere after about a year, meaning that from an environmental standpoint they have much lower impact.

Both R744 and HFO1234yf are being considered, but it looks like HFO1234yf has won out.

HFO1234yf costs about 3% more than r134a to use in new vehicles, performs the same, uses the same type of compressor(fixed swash plate instead of variable like with r744 systems), and is a drop in conversion for r134a in older vehicles.

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I'm not sure what R-152 is made of, but I just remembered that I have a can of Memorex air dust here, and a can of R-134 Arctic Breeze. So let me have a look.

Memorex: Difluoroethane, CAS 75-37-6.

Arctic Breeze: 1,1,1,2 Tetrafluoroethane, CAS 811-97-2

Obviously the Memorex has a slightly different ingredient now, but I do recall purchasing some air dust cans previously that were marked with exactly the same descriptor as the actual R134 cans.

_________________
Proud supporting vendor of LOST Jeeps
TRAVELING CRD TECH. I come to you!
Need help? Just ask! I've taken it apart more than most.
Email jeep [at] maincomputer [dot] com - BOARD MESSAGING IS BROKEN
Over 225 CRDs currently driving with my valves, timing belt, rockers, or ARP Studs.
Bad noises = REALLY bad things.

"1,1-Difluoroethane is a organofluorine compound with the chemical formula C2H4F2. This colorless gas is used as a refrigerant, where it is often listed as R-152a or HFC-152a. As an alternative to chlorofluorocarbons, it has an ozone depletion potential of zero and a lower global warming potential[2]. It has recently been approved for use in automobile applications as an alternative to R-134a."

http://en.wikipedia.org/wiki/1,1-Difluoroethane

Think you got owned on that one buddy.I know a bit more about automotive AC systems,I am MACS certified(must for CO),EPA certified,GM certified,Chrysler certified,and ASE certified in automotive AC systems.

Can't use R12 stuff for R134A,machines/fittings are different.

R152A will never be used in the automotive side,it is flamable.AC Delco is trying to push it but automakers are pushing back with some other form called R172A(if I remember correctly).

Yup, there are other flammable refrigerants that will never be used(and which are marketed by companies for r12 conversion, even though they ARE NOT approved for automotive use), hence why HFO-1234yf is being phased in starting in 2013 for GM vehicles.

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http://www.Colorado4Wheel.com
"Its not about what you can DO with your Jeep, its about where you can GO with your Jeep."
Knowledgeable - But Caustic