Toxic/Hazardous Chemicals In HVACR

[botrous]

I think this may interrest the most of us , for our own safety
http://www.refrigtech.com/zhazmatc.htm

Regards

[Greg W]

Put it this way , I dont see many old fridgys

[botrous]

Maybe you don't see it but it exsists

[Greg W]

A few might , and alot have died. Cancer.

[US Iceman]

Hi Guys,

Try ammonia, leave the other stuff!

There are more old ammonia guys than the others. At least that has been my experience.

Ammonia won't cause your body parts to swell, but it can make other body parts pucker up.

Regards,

[Argus]

Hi Guys,

Try ammonia, leave the other stuff!

Sulphur Dioxide for me, every time!

Bring it back and never worry about leaks again.

.
________
Honda SL90

[US Iceman]

Hi Argus,

OK, you win!

This is more fragrant than ammonia. I have to agree with you though. If we were still using SO2, everyone would make sure there were no leaks.

The best way to demostrate this is to light a sulphur stick when checking ammonia leaks. This stuff is worse than ammonia.

Do you think we can get anyone who wants to particpate?

Best Regards,
US Iceman

[botrous]

Do you think we can get anyone who wants to particpate?

Not if i have to smell ammonia

[US Iceman]

Hi Botrous,

Don't be afraid of a little stink.

Ammonia is biodegradable and no ODP, your body can metabolize small quantities of it , it can open your sinus cavities , it will give a grown man diaper rash , and no one wants to work with it .

Now that's job security!

The smell is part of the safety feature. I guarantee the smell will let you know when it is present. Not like the other stuff.

Comparing ammonia to SO2 is like comparing air freshener to old road kill.

Cheers,
US Iceman

[Argus]

Comparing ammonia to SO2 is like comparing air freshener to old road kill.

Cheers,
US Iceman

Good morning Mr Iceman,

I never said Sulphur was fragrant!

If it?s fragrance you want, try Methyl! Come to think of it, Methyl?s probably a good candidate these days as fewer people are smokers!

Thomas Midgeley?s spinning in his grave because of the restrictions on his wonder inventions.

Glad you and I can remember some of the old stuff. Who said that old fridge engineers never collect their pensions?

All best,
________
buy herbalaire

[US Iceman]

Hi Argus,

My point in all this with a "tongue in cheek" approach was to say sulphur dioxide smells worse than ammonia.

Anyone who has worked on ammonia systems can tolerate small amounts without any discomfort. SO2 is different. I'm not sure anyone could tolerate this stuff!

I almost mentioned Methyl Chloride since this was also in prominent use during the same time. This would really thin the ranks of smoking refrigeration guys!

Since everyone used to use the halide torches for leak checking, you can imagine what would happen. I have heard of first hand accounts from the person who inadvertently did this. Lesson learned.

History is an interesting subject. I hope we have learned from it and don't go back to using some of these refrigerants.

This does bring up an interesting thought. Why are people afraid of ammonia, but the halocarbons are OK?

The stink, maybe?

Look at natural gas. In it's natural state it is odorless. The odorizer is added to give it a smell. Ethyl mercaptan, I believe.

From my viewpoint, the other refrigerants are more dangerous.

What you can't smell can hurt you!

It's always nice to talk to an old salt.

Best Regards,
US Iceman

[Argus]

Mr Iceman, I Fully agree with you ? Sulphur Dioxide is totally intolerable. Positively toxic. Ammonia advertises its presence, but there is the hazard of low concentration flammability, not to mention the way that it can taint some foodstuffs if it is present.

What is it about ammonia? I don?t know. All refrigerants are potentially harmful. I?m convinced that we still underestimate the effects and also the incidents of cardiac sensitisation when exposed to Fluorocarbons.
This link is about a small exploding (!) ?minibar? type absorption fridge taken from the Scotsman newspaper earlier this year. I?ll leave you to draw your own conclusions. What is obvious is that the authorities always overreact ? it gave them a chance to close down half of Edinburgh and pretend it?s something serious.
http://news.scotsman.com/edinburgh.cfm?id=67562005

I was having a wry smile, especially when you consider the candidate list of refrigerant substances, including chloroform and sulphuric acid as an absorbent. I came into the trade when some of these older substances were still around?. just. You could always tell a Methyl plant by the quantity of Alcohol phials littering the floor!

Thomas Midgeley is credited with initiating an environmental double whammy when he topped off his career in tetraethyl alcohol with fluorocarbons, but it was the state of knowledge as it existed at that time. We cannot ignore the fact that lives were lost due to accidents with both sulphur and ammonia when they were in universal use as direct refrigerants. We consider that FCs are ?safe? even if not totally environmentally benign, but they still have their hazards if used unwisely. Nobody in their right mind would repeat his trick of inhaling neat R12 and extinguishing a candle to demonstrate its harmlessness.

Having said that, the invention of CFCs, made small hermetic systems possible safe and universally affordable. The market in new domestic refrigerators manufactured in Europe is almost exclusively converted to HCs these days. They are considered safe, but we still cannot overlook the fact that they are classed A3 (higher flammability) in the safety standards. To my knowledge, the purified propanes do not have an odour trace added. However there is an upper quantity limit when used in direct systems?.. about 2kg, I think
________
F engine

[US Iceman]

All refrigerants are potentially harmful.

I completely agree. This is a mode of thinking that should be instilled in any refrigeration person.

I happened to be in a high concentration atmosphere with R-22 back in my younger days. I believed the reports that the refrigerant was totally benign and safe. After about an hour or so, I started to get sick, dizzy, chest pains, shortness of breath, etc. I barely made it under my own power.

It took about three or four days before I felt better. Since then, as far as I am concerned, all refrigerants are extremely dangerous and should be treated as such. Not long after this I started to make the switch to NH3 systems.

I have a mentor who was involved in an ammonia contamination event with foodstuffs. He took the food and placed in a refrigerated rail car (away from people). After some time the food degassed the ammonia, The food was tested (lab & taste) with no discernible difference. Lobsters I think.

The area of vapor flammability is interesting: 16-25% volume concentration or 160,000-250,000 PPM. That is a lot of ammonia. To my knowledge, ammonia in this range will burn if an ignition source is present at approx. 1200F (648C). Remove the ignition source and the combustion process ceases.

Unfortunately, when ammonia leaks out, so does some oil. Oil has a much lower ignition point and will sustain combustion. While the ammonia does stink, my concern is the oil, from a flammability issue.

Another area is the so-called explosive effect. When ammonia does ignite, the event is a deflagration, not a real high pressure explosion. Much less energy potential.

No doubt, Mr. Midgeley's creation contributed to a large growth of refrigeration. It basically ushered in the era of affordable and dependable cooling and could be associated with the end of the SO2 residential refrigerators.

Propane (R-290) is a very good refrigerant also. But when you use it in industrial applications a new level of complexity is incurred.

A great discussion on refrigerants and safety. Thank you for your comments.

Cheers...