LETHAL R-134a concentrations from evaporator failure
g...@worldserver.com
LETHAL R-134a CONCENTRATIONS IN PASSENGER COMPARTMENTS MAY OCCUR
FROM EVAPORATOR FAILURE
In August 1997, a study was done at the Armstrong laboratory, Wright
Patterson Air Force Base, Dayton, OH. The report, "Human Inhalation of
Halon 1301, HFC-134a and HFC-227ea for Collection of Pharmacokinetic
Data" was authored by A. Vinegar, R. Cook, J McCafferty, M. Caracci, and
G. Jepson.
The concentration of R-134a being used was extremely low and (then
thought) that nothing bad was going to happen. To quote from the bottom
of page 10 (page 11 if abstract prepended), "Subject #3 was the first
volunteer exposed to
HFC-134a. The exposure concentration was 4000 ppm (0.4% v/v) and was
scheduled to last for 30 minutes with a 5 minute postexposure evaluation
period as was accomplished in the Halon 1301 portion of the study.
Approximately 4.5 minutes into the exposure, the subject lost
consciousness and both pulse and blood pressure dropped to zero."
The test was aborted and medical personnel intervened and revived the
subject.
Suppose it wasnt a test in a medical lab, that person would be "dead".
The industry, has in general, tried to "coverup" this "problem", often
reporting "Human Subject Faints During Botched Air Force R-134a
Inhalation test". They then go on to theorize that the nurse wiggled the
blood drawing needle and that made the subject "faint". See (on the web)
www.autofrost.com/humanhal2.pdf to download your own copy or call Monroe
Air Tech at 1-800-424-3836 for a copy. Be your own judge. Using "0.4%"
(4000 ppm) parts per million of R-134a vapor in air as the "lethal"
amount, the following calculations were performed on several late model
cars. They assume a bad evaporator leak or rupture, allowing the factory
listed charge amount
to escape into the passenger compartment. R-134a is heavier than air, so
if the air is not "stirred" by a fan, heavier concentrations will be
found in low spots and lower in high spots. For these purposes, we will
assume the air is stirred and the concentration is uniform.
The specific Volume of R-134a vapor at "normal" pressure (from the NIST
Standard Reference Database 23 "NIST THERMODYNAMIC PROPERTIES OF
REFRIGERANTS AND REFRIGERANT MIXTURES") is 3.69 cubic feet per pound
(cf/lb). If you blow off a 1 lb can of R-134a into am empty garbage bag
(sealed), it will occupy 3.69 cubic feet.
SPECVOL134a CF R-134a CHG lb 1 1,000,000 parts
conc. (ppm) = ----------- X ------------- X -------- X
----------------
lb Int.Vol CF per million
1998 CAR Interior(CF) lb R134a pass.conc ppm Times
lethal
Ford Escort 87 1.75 74,224 18.6
GEO Prism 84 1.7 74,679 18.7
Chevy Cavalier 92 1.5 60,163 15.0
Ford Taurus 101 2.13 77,819 19.5
Ford F150* 80 2.38 109,778 27.4
Toyota Camry 96.8 1.88 71,665 17.9
Ford Mustang 83 2.13 94,695 23.7
Chevy Malibu 98.6 1.75 65,492 16.4
Honda Accord 90.4 1.43 58,371 14.6
Chevy S-10* 80 2 92,250 23.1
Chevy MonteCarlo 96.1 2 76,795 19.2
Olds Cutlass Supreme 95 1.75 67,974 17.0
Buick Skylark 87 2.25 95,431 23.9
BMW 5 Series 93.5 3.27 129,051 32.3
* Estimated, since interior volume was not available
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David Walker
g...@worldserver.com wrote:
>The test was aborted and medical personnel intervened and revived the
>subject.
>Suppose it wasnt a test in a medical lab, that person would be "dead".
Suppose I am in my car driving down the road and my evap blows it's
guts out. If I am a person with any sense at all, I roll down the
window, and I can guarantee you, I do not pas out. Now, if I am
setting at a red light and the same thing happens, if I sit in the car
long enough to pass out I am 1)very stupid and 2) such a waste of
matter in the universe that my passing will not matter.
>to escape into the passenger compartment. R-134a is heavier than air, so
>if the air is not "stirred" by a fan, heavier concentrations will be
>found in low spots and lower in high spots. For these purposes, we will
>assume the air is stirred and the concentration is uniform.
>
Like I said, a window down at 60 mph will do plenty of "stirring".
Give me a break and go do a radon test on you're home.
David
E. William Lawrence III
What a load of horse crap!
4000 ppm of just about anything will kill something for sure, except
maybe oxygen or nitrogen!
Another scare tactic to sell a different product.
That's all I'm going to say as I personally don't make many comments
without proof as this fool did.
What about laws that prohibit human tests of this type, I guess that they
just ignored them huh?
g...@worldserver.com wrote:
>
> LETHAL R-134a CONCENTRATIONS IN PASSENGER COMPARTMENTS MAY OCCUR
> FROM EVAPORATOR FAILURE
>
> In August 1997, a study was done at the Armstrong laboratory, Wright
> Patterson Air Force Base, Dayton, OH. The report, "Human Inhalation of
> Halon 1301, HFC-134a and HFC-227ea for Collection of Pharmacokinetic
> Data" was authored by A. Vinegar, R. Cook, J McCafferty, M. Caracci, and
> G. Jepson.
>
> The concentration of R-134a being used was extremely low and (then
> thought) that nothing bad was going to happen. To quote from the bottom
> of page 10 (page 11 if abstract prepended), "Subject #3 was the first
> volunteer exposed to
>
> HFC-134a. The exposure concentration was 4000 ppm (0.4% v/v) and was
> scheduled to last for 30 minutes with a 5 minute postexposure evaluation
> period as was accomplished in the Halon 1301 portion of the study.
> Approximately 4.5 minutes into the exposure, the subject lost
> consciousness and both pulse and blood pressure dropped to zero."
>
> The test was aborted and medical personnel intervened and revived the
> subject.
> Suppose it wasnt a test in a medical lab, that person would be "dead".
>
> The industry, has in general, tried to "coverup" this "problem", often
> reporting "Human Subject Faints During Botched Air Force R-134a
> Inhalation test". They then go on to theorize that the nurse wiggled the
> blood drawing needle and that made the subject "faint". See (on the web)
> www.autofrost.com/humanhal2.pdf to download your own copy or call Monroe
> Air Tech at 1-800-424-3836 for a copy. Be your own judge. Using "0.4%"
> (4000 ppm) parts per million of R-134a vapor in air as the "lethal"
> amount, the following calculations were performed on several late model
> cars. They assume a bad evaporator leak or rupture, allowing the factory
> listed charge amount
>
> to escape into the passenger compartment. R-134a is heavier than air, so
> if the air is not "stirred" by a fan, heavier concentrations will be
> found in low spots and lower in high spots. For these purposes, we will
> assume the air is stirred and the concentration is uniform.
>
Adrian Brigham
would help your side to do the same rather than just referring to his
arguments as "a load of crap".
Adrian B.
L. Smith
Halon systems use the same general types of fluorocarbons, and have
been used without incident, to my knowledge.
These gases are not acutely toxic, but could asphyxiate you if they
filled your area.
Just like carbon dioxide and nitrogen can do. Do you know of anyone
who has died from riding in a closed automobile with 2-3 other people
using up the oxygen and exhaling carbon dioxide and nitrogen?
Sure, I guess it is possible. But I think he's probably right...it most
likely is a load of crap.
--
- Larry Smith Sr
Remove NOSPAM for email replies
Don Saunders
E. William Lawrence III wrote:
(snip)
> 4000 ppm of just about anything will kill something for sure, except
> maybe oxygen or nitrogen!
(snip)
A little research might help your argument. One of the major
manufacturers of CFC 12 used an animal test as part of their
manhufacturing specs. 100% of the test animals had to survive 24 hours
in an atmosphere of 20% oxygen and 80% CFC - i.e., the nitrogen was
replaced by CFC.
On the issue of whether or not 134a can be lethal to passengers:
How likely is a total release in a short period with no introduction of
outside air?
Anyone truly concerned that this might happen in their car has the
choice of eliminating the danger by having their AC system evacuated.
Cars are lethal in many ways. Anyone who gets in one should recognize
that they are one of the leading causes of death in the US. Potential
leakage of refrigerant from the AC unit should be the least of their
worries.
Let's keep in mind that RISK is a combination of HAZARD (toxicity) and
EXPOSURE. Without both, there is no risk.
A note to the anti-chemical crowd: The most toxic chemical known to
mankind is a natural product, has the potential to be present on your
dinner plate especially if you eat only 'organic' food, and kills very
few people in the US each year (my guess is less than 10).
Don--
Phil Irvine
In article <347836...@tanstaaflgroup.com>,
>On the issue of whether or not 134a can be lethal to passengers:
> How likely is a total release in a short period with no
introduction of
>outside air?
> Anyone truly concerned that this might happen in their car has the
>choice of eliminating the danger by having their AC system evacuated.
> Cars are lethal in many ways. Anyone who gets in one should
recognize
>that they are one of the leading causes of death in the US. Potential
>leakage of refrigerant from the AC unit should be the least of their
>worries.
>
>Let's keep in mind that RISK is a combination of HAZARD (toxicity) and
>EXPOSURE. Without both, there is no risk.
Using this argument (about amount of leakage), you can not argue against
the use of Hydrocarbon refrigerants in automobile A/C systems. The ONLY
argument used against them is the possibility of explosion in the cabin
from massive leakage. If there is no leakage then there is no risk (as
studies have shown conclusively) and we should be using them for all the
other good reasons which have been mentioned previously. (isn't this taking
the thread back to where it started weeks ago?).
Phil
Adrian Brigham
reader of postings I will give a lot more attention and credence to
logical, documented, and well stated arguments rather than, shall we say
"crap".
Adrian
Jim Declension
E. William Lawrence III wrote:
>
> What a load of horse crap!
> 4000 ppm of just about anything will kill something for sure, except
> maybe oxygen or nitrogen!
> Another scare tactic to sell a different product.
> That's all I'm going to say as I personally don't make many comments
> without proof as this fool did.
Um, sorry, but the original poster was discussing a study. He even posted the
exact title, venue and authors of the study, so that anybody who wishes to can
examine the original document for himself. Given that fact, it is not likely
that the original poster is lying about the existence of the study or about
any of its particulars, because he would be found out (and likely exposed)
quickly by the first person who checked the cited reference.
Now--do you have any particular study that tends to show that what the
original poster said is a "load of horse crap", or is this just your opinion,
based perhaps on what you might have heard or based on what "everybody knows"?
If you have evidence, present it. Otherwise, quit shooting-off your mouth,
because you're not providing any useful information and you're just making
yourself look dumb.
Jim
K7LDX
L. Smith
I. W. Stirn wrote:
>
> L. Smith wrote:
>
> > Halon systems use the same general types of fluorocarbons, and have
> > been used without incident, to my knowledge.
> >
>
> fires has been know to asphyxiate the crew.
>
> --
> Sincerely, I. W. Stirn
>
> ---------------------------------------------------------------
>
>
> L. Smith wrote:
>
> Halon systems use the same general types of fluorocarbons,
> and have
> been used without incident, to my knowledge.
>
>
> extinguishing fires has been know to asphyxiate the crew.
>
> --
> Sincerely, I. W. Stirn
> Can you give some details about this ?
E. William Lawrence III
Jim Declension wrote:
>
> E. William Lawrence III wrote:
> >
> > What a load of horse crap!
> > 4000 ppm of just about anything will kill something for sure, except
> > maybe oxygen or nitrogen!
> > Another scare tactic to sell a different product.
> > That's all I'm going to say as I personally don't make many comments
> > without proof as this fool did.
>
> Um, sorry, but the original poster was discussing a study. He even posted the
> exact title, venue and authors of the study, so that anybody who wishes to can
> examine the original document for himself. Given that fact, it is not likely
> that the original poster is lying about the existence of the study or about
> any of its particulars, because he would be found out (and likely exposed)
> quickly by the first person who checked the cited reference.
>
> Now--do you have any particular study that tends to show that what the
> original poster said is a "load of horse crap", or is this just your opinion,
> based perhaps on what you might have heard or based on what "everybody knows"?
> If you have evidence, present it. Otherwise, quit shooting-off your mouth,
> because you're not providing any useful information and you're just making
> yourself look dumb.
>
> Jim
> K7LDX
>
Jim,
In retrospect I almost have to agree, I am not sure what was going
through my mind when I wrote that. I posted a retraction the other day
concerning my original post in a couple of newsgroups.
Thanks for the response. In the future I will use my brain. (duh)
I still don't believe that the original post was factual information,
perhaps I need to read a copy of the document he mentioned.
As I stated in my last post, I believe he was pushing his product by
using a scare tactic and some obscure reference.
Happy Holidays,
Bill
Marc O'Brien
Been getting worse but started about 5 years ago. My heart has
acquired a funny rhythm. It started off with me having the occasional
painless sensation of what I might describe as a baby frog in the
left of my chest making the odd kick. I stress there is absolutely no
pain. These recent months my heart sounds and feels like this
"ba-dum..ba-dum..ba-dum.dum.dum.......BA-DUM..ba-dum..ba.dum......BA-D
UM..ba-dum..ba-dum. Feeling my pulse the only evidence of all this is
the frequent but infrequent, if you know what I mean, seemingly
skipped beat i.e. thump..thump..thump..........THUMP..thump..etc.
This irregularity only really occurs in the evening when I'm relaxed
and perhaps more so after a meal. I will add that I have put on about
30Kg since I came to the UK from South Africa 4 years. If I have a
beer or do some exercise then all is okay i.e. no irregularities
evident.
Yes, there have been occasions in the distant past when I've done
gas welding in the presence of freon contaminated atmospheres
inhaling acidy burnt freon by-products.
My thoughts are too lose weight and get fit before going to a Doc
and asking for a pace maker although I might want to do that back in
South Africa rather, the UK medical services don't exactly inspire
confidence a bit like their sport.
Any comments or heart doners?