Info for R12 users

[ChrisM911SC]

In theory yes, but it's got to have something to do with the possibility that propane is a component of the mixture. I'll try to get the MSDS sheets and post them. If ES-12 was indeed safe, the EPA would be promoting the heck out of it. Commercial, residential and automotive applications would be changing everywhere with similar refrigerants available, due to the non-ozone depleting factors as well as no recovery or recycling of refrigerants.

[PatrickB]

Can I ask a really DUMB question Chris?

Uhmmm... Is this stuff legal to put in our cars? Or more importantly, is it legal to sell and purchase for the use of in a car? Or is this hopefully one that is currently slipping by regulation....

[PatrickB]

Originally posted by Jim Sims
Don't confuse autoignition temperatures with flammability.

See:

http://www.epa.gov/ozone/snap/refrigerants/hc12alng.html#q8

Jeez Jim, you guys have all the answers

I guess the above link dispells any questions of leagaity!!!

Buy it while you can, but use it at your own risk.........

[PatrickB]

Damn... forgot to spell check! LEGALITY?

[ChrisM911SC]

Thanks for the articles Jim. This thread has really gone a long way in a short time.

Can I ask a really dumb question now...what are the temperature readings at the vents for those of you that have done the R134a retrofit?

[Bobboloo]

I knew I really didn't want A/C in the 911 anyway.

[PatrickB]

After a fresh charge, I will usually see a 30 degree difference at the floor vent vs. outside air temp when car is moving on the freeway.... OK, I guess, as long as it doesn't get above 95 outside.... I used to see about a 40 degree difference with the wonderful R-12... If I can score some of this new stuff, and it really works in my system, I might just just buy a couple of cases of it, and store it next to the rest of my militia gear...

[wholberg]

This link takes you to a MSDS for Envirosafe refigerant. The composition, as listed on the MSDS is 0-60% C3H8 (propane) and 0-60% C5H10 (probably cyclopentane). Both are flammable, and propane appears to be a major component. Cyclopentane is slightly less flammable than propane, and linear pentane derivatives that fit that formula will be just as bad as propane.

http://befreetech.com/esmsds.htm



The MSDS for cyclopentane is below.

http://ptcl.chem.ox.ac.uk/MSDS/CY/cyclopentane.html


Per the MSDS, cyclopentane is "Highly flammable. Note low flash point and wide explosion limits. Incompatible with strong oxidizing agents. Floats on water so water is of limited value in putting out fires involving this material."


If you choose to use it your car, just be aware of, and take responsibility for, the risks. After all, it IS still a free country.

[ChrisM911SC]

remember 134a is 1,1,1 tetrafluoroethane

I'm not sure this makes me feel any better either.

[wholberg]

Originally posted by ChrisM911SC
remember 134a is 1,1,1 tetrafluoroethane

I'm not sure this makes me feel any better either.

The fluorines make it a lot less flammable than propane or another hydrocarbon. For instance, chloroform, CCl4, was used in pump style fire extinguishers up until the 30's or '40's.

Another very good refrigerant is ammonia. Of course, if you could get past the severe toxicity, you sure would know if you had a leak in your system.

[ChrisM911SC]

Another quote;
"The autoignition temp of 134a is 368F !!! Not only is that do-able under the hood, but if you breathe it at only 4000 parts per million, you die".

[R. Aster]

Originally posted by ChrisM911SC
Can I ask a really dumb question now...what are the temperature readings at the vents for those of you that have done the R134a retrofit?

In the PDF about the professor's experiment, with the coolant he used, I think they mentioned that the vents were approximately 2000 degrees cooler than the professor's head...

[PatrickB]

perhaps the flame aided in causing a chain reaction (autoigition) by the new higher temperature inside the Professor's chamber of horrors?

[Jim Sims]

"but if you breathe it at only 4000 parts per million, you die".

Sigh!

The below is from:

http://www.trane.com/commercial/issues/environmental/cfc6.asp#toc

R-134a toxicology.[10] R-134a also has very low acute inhalation toxicity. The lowest concentration that causes mortality in rats, the 4-hour Approximate Lethal Concentration (ALC), exceeds 500,000 ppm. The cardiac sensitization response level for R-134a is approximately 75,000 ppm. Anesthetic-like effects are observed at concentrations greater than 200,000 ppm, or 20%.

Long-term exposures with very high concentrations (50,000 ppm) caused an increased incidence of benign tumors in the testis of rats. Again, none of the observed tumors were life threatening, and all occurred near the end of the study. The evidence from all tests in cultured cells or organisms, as well as in laboratory animals, indicates that R-134a is not genotoxic and that the increased incidence in benign tumors is not due to an effect on genetic material.

The test findings indicate that R-134a has very low acute and subchronic inhalation toxicity, is not a developmental toxicant, and is not genotoxic.[10] Most refrigerant manufacturers recommend that TWA occupational exposures not exceed 1,000 ppm; this also is the level recommended by the American Industrial Hygiene Association, Workplace Environmental Exposure Limit (WEEL) Committee.[11] Again, exposures still should be kept to the practicable minimum. (A WEEL guide has not been published for R- 123 at this time.)

It is important to note that the tumors attributable to the R- 123 and R-134a exposures were not cancerous. The findings reflect an increase in tumor incidence compared to rats in the experimental control group, those not exposed to the refrigerants. Some tumors also were observed in this control group, but not as many.

Also, the recommended occupational exposure limit for each refrigerant is below the level at which toxic effects were observed in laboratory animals. The use of rats, dogs and other animals is based on accepted scientific procedures and sensitivities to specific concerns by species. The lower exposure limit affords both a margin of safety and a conservative reflection of potential differences, between responses in individual humans and between humans and test animals.

Other refrigerants. Information on the toxicity of other refrigerants is available from chemical manufacturers, published literature ,and chemical and safety databases. The toxicology findings for other refrigerants covered by PAFT are also available.[10]

R-123 and R-134a were summarized here as the newest of the widely used refrigerants for chillers. Other chiller refrigerants are addressed in less detail below, and a survey of toxicity data is underway, by the author, on alternative refrigerants for additional applications.[12]

[Joeaksa]

Originally posted by PatrickB
Jeez Joe... 38-40 at the vent? I'd be spending my Arizona summer's in the car, not the house!!

Patrick,

At home I can lounge by the pool with a margarita in hand legally. Same cannot be said about the car!

JoeA

[PatrickB]

If you new that your system was leaking, It would be important to know if it was leaking "into" the system, and mixing with air entering the cabin... If it was leaking out of the closed system, obviously it would likely dissapate before causing any human harm? How much refrigerant actually ever bleeds into the closed system exposing possible harm to those in the car?

Yikes... Where is this thread going??

[mschuep]

Without drawing my comments out for too long, let me say I have researched this topic before.
I found a link that was especially helpful for me. Of course, it is on the net, so take it for what its worth, but it certainly seems to clearly explain most common questions, facts, and myths about refrigerants, retro-fits, risks, and what should be done when switching between the various refrigerants. I read the articles from the beginning down to the following line and was satisfied. (about 2 pages)

"Discussion and alternative automotive refrigerants"

Hope this helps somebody
-Matt

[mschuep]

oooops!

http://www.allpar.com/eek/ac.html

[ChrisM911SC]

Yeah Joe, but what's the temperature of your pool?

[wholberg]

Originally posted by Jim Sims
[B

R-134a toxicology.[10] R-134a also has very low acute inhalation toxicity...[/B]

Jim is correct. It is important to know that R-134a is known in drug delivery circles as HFA (hydroxyfluoroalkane) 134a and is the only current approvable inhalation drug delivery propellant in North America and Europe. It is used to deliver millions of doses of asthma and other drugs to people all over the world in MDI's (metered dose inhalers).

The HFA molecule is also about twice as large as an R-12 molecule, but the hoses in older cars will allow 134a to diffuse through the hose material, neccesitating the use of barrier hoses for conversions on older cars.