Viton o-rings

[47silver]

I was reading a haynes manual and in the section on fluids, gaskets etc, it stated that viton o-rings when burned release a very nasty acid which can cause serious burns. my question do our Porsches use Viton o-rings that should be a concern when the orings are exposed to high temperature or flames?

[mattC2993]

I've used lots of Viton o-rings in the industrial equipment business and never heard of that. I suppose there are lots of elastomers and materials that would release harmful vapors if exposed to high temps. or fire. Why would Viton o-rings be exposed to high heat or flames in an engine? The max. working temp for Viton is around 400F.

[boyt911sc]

Originally Posted by 47silver

I was reading a haynes manual and in the section on fluids, gaskets etc, it stated that viton o-rings when burned release a very nasty acid which can cause serious burns. my question do our Porsches use Viton o-rings that should be a concern when the orings are exposed to high temperature or flames?

47silver,

It maybe true that the Viton elastomer could generate some toxic acid/s when ignited. The only time these viton o-rings would be exposed to this condition would be when your engine is on fire!!!! And your concern about being exposed to this nasty acid (?) should be your last concern. Your engine is on fire and you worry about this miniscule amount of acid (?). The viton o-rings are imbedded in the engine parts and by the time it got exposed to high temperature would be when you car is incinerated by an accidental fire. You worry too much. The 20 gallons of high octane fuel in your tank pose more danger to you than these viton o-rings.

Tony

[fanaudical]

I have also handled/specified more than my share of Viton O-rings over the years. There is some truth to what the OP presents: Viton, being a fluoroelastomer, does release hydrogen fluoride gas (forms hydrofluoric acid in presence of water vapor) upon incineration. Precautionary handling is simple: Don't let them ignite.

Here's a link to Dupont's handling guide for Viton elastomers:

http://www2.dupont.com/Plastics/en_US/pfo/assets/downloads/viton/Handling%20Precautions%20for%20Viton%20and%20Relat ed%20Chemicals.pdf

[47silver]

I posted this for 2 reasons:
1. there are some threads about cars that catch fire and the owner wants to repair them rather than junk them.
2. A lot of us buy used parts so it would seem prudent to know that some of these seals can lead to serious injury if they were exposed to flames.

I would imagine that fuel related o-rings and perhaps refrigerant o-rings and many of the motor and transmission seals could be viton. Being in the engine bay where fires usually occur i would expect them to be subjected to melting or fire damage.
From what i read the o-rings once burned can be higly acidic and can lead to serious injury so knowing where they may be located would be something that would be good to know.
I for one never gave it a thought about handling old o-rings from used parts so after reading about the dangers I will procede with caution.

[tharbert]

Even exposure to ever-present grease, oil and brake fluid can cause health issues, right? I, for one, normally wear latex or Mechanix gloves when working on my car. As a general rule, I avoid licking or rubbing tender body parts on any auto part...except when I got my new P/C's from Henry. But, if you feel the need, break out the face shield, respirator and skin protection. No one ever said "I wore too much protection."

[Lyle O]

The total amount of Viton in these 911s is so small that if there ever was a fire, you would have way more toxic out-gassing from other more prevalent materials, like hoses and rubber parts, than from any Viton. Most of the that (what little there is) is burried in your engine (valve stem seals, main crank seal etc.). No need to be OCD about this...

[boyt911sc]

Originally Posted by Lyle O

The total amount of Viton in these 911s is so small that if there ever was a fire, you would have way more toxic out-gassing from other more prevalent materials, like hoses and rubber parts, than from any Viton. Most of the that (what little there is) is burried in your engine (valve stem seals, main crank seal etc.). No need to be OCD about this...

Lyle,

That's the same way I look at this situation. Unless you have Viton o-rings the size of a Dunkin donuts!!!!!! Safety is first and foremost but you need some common sense too.

Tony

[Lyle O]

Originally Posted by boyt911sc

Lyle,

That's the same way I look at this situation. Unless you have Viton o-rings the size of a Dunkin donuts!!!!!! Safety is first and foremost but you need some common sense too.

Tony

Amen! These cars are supposed to be fun!

[Discseven]

Originally Posted by boyt911sc

47silver,

It maybe true that the Viton elastomer could generate some toxic acid/s when ignited. The only time these viton o-rings would be exposed to this condition would be when your engine is on fire!!!! And your concern about being exposed to this nasty acid (?) should be your last concern.

Tony

[47silver]

First of all i don't wear a ballet skirt so cool it with the macho.

this if from the Haynes manual on my f150 concerning hydrofluoric acid:
".. above 750 degrees....the rubber changes into a charred or sticky substance containing hydrofluoric acid. Once formed the acid remains dangerous for years. If it gets onto the skin, it may be necessary to amputate the limb concerned".

many time we take things apart without gloves or use them to do other work so
the "dangerous for years" and "amputate the limb" is what got my attention.

If you think you are immune to this potential problem why bother to comment and attempt to belittle what I stated. Burns are not fun and if this thread helps someone from getting hurt why would you consider it unmanly to be concerned about safety?

there was a recent thread about a car on fire in the engine department, he wondered about repairing the car, i read about this acid and asked an honest question about areas of concern.
You could have answered without comment as follows: there are not any o-rings to concerned with.
or there are o-rings to be concerned with.
Any other comments serve not purpose.

[rusnak]

"cool it with the macho"

LOL that was hilarious!

Good point about the dangers of forensic repairs. I think generally speaking, it's a good idea to wear latex gloves. I like the black "Venom" ones, and wear them when changing hydraulic oil, working on AC, etc. When working with parts that are hot, I wear my welder's gloves. I guess I'm getting old and frail, haha!

[boyt911sc]

Originally Posted by 47silver

First of all i don't wear a ballet skirt so cool it with the macho.

this if from the Haynes manual on my f150 concerning hydrofluoric acid:
".. above 750 degrees....the rubber changes into a charred or sticky substance containing hydrofluoric acid. Once formed the acid remains dangerous for years. If it gets onto the skin, it may be necessary to amputate the limb concerned".

many time we take things apart without gloves or use them to do other work so
the "dangerous for years" and "amputate the limb" is what got my attention.

If you think you are immune to this potential problem why bother to comment and attempt to belittle what I stated. Burns are not fun and if this thread helps someone from getting hurt why would you consider it unmanly to be concerned about safety?

there was a recent thread about a car on fire in the engine department, he wondered about repairing the car, i read about this acid and asked an honest question about areas of concern.
You could have answered without comment as follows: there are not any o-rings to concerned with.
or there are o-rings to be concerned with.
Any other comments serve not purpose.

47silver,

The article you read from Haynes manual (UK) about HF from Viton o-rings is misleading and not totally accurate. An incident in 1981 in a laboratory at National Nuclear Corp. (UK) after experimenting a sealed vessel using Viton o-ring at 400 deg. Celsius produced hydroflouric acid. The mechanic disassembled the high pressure vessel under pressure and was burnt by the acid. The finger that was burnt was eventually amputated.

FACTS:

1). There is no verifiable incident about HF in burnt vehicles any where in the world.
2). HF will immediately dispersed when exposed to flames.
3). It is rather difficult to produce a 600 psi. pressure (pressure used in the laboratory test) in an automobile engine fire.
4). The hydroflouric acid that burnt the finger of the technician/mechanic was produced in a experiment using ultra high temperature and pressure. Unlikely to occur outside a laboratory.
5). Use of protective gloves is highly recommended to keep your hands from dirt and other contaminants.

Read the report of HSE (Health and Safety Executive - UK) about HF from viton (flouroelastomers).

Tony

[mattC2993]

I'd be more worried about the refinery down the road (depending where you live) that uses HF acid in their alky unit. A cloud of that stuff would scare me.

[rusnak]

Well, we are not living in 1984, and this is not Bhopal, and it's not as if you are crusading against Monsanto. Or ARE you...hmm

[47silver]

Haha, thou thinks thy protest too much

[chris_seven]

Fluoroelastomers in motor vehicle repair (MVR)

[47silver]

i only wanted to know if we had any o-rings that may be a problem, the Haynes manual said that they could be concern.

The HSE article reads:

"The incident was investigated by HSE and, on repeating the experiment it was shown that hydrofluoric acid (HF) was produced (from hydrogen fluoride gas in presence of water). It can cause corrosive burns due to free hydrogen ions, and chemical burns from tissue penetration by fluoride ions. However, it is readily treated by the use of calcium gluoconate gel"

so in other words it can be acidic and it can burn into the tissue but if it does just have come cgg on hand to treat it.

[boyt911sc]

Originally Posted by 47silver

i only wanted to know if we had any o-rings that may be a problem, the Haynes manual said that they could be concern.

The HSE article reads:

"The incident was investigated by HSE and, on repeating the experiment it was shown that hydrofluoric acid (HF) was produced (from hydrogen fluoride gas in presence of water). It can cause corrosive burns due to free hydrogen ions, and chemical burns from tissue penetration by fluoride ions. However, it is readily treated by the use of calcium gluoconate gel"

so in other words it can be acidic and it can burn into the tissue but if it does just have come cgg on hand to treat it.

Please go back and read the report. The production of HF was conducted in a Nuclear laboratory under severe conditions that could be hardly duplicated outside a laboratory environment. Plus the technician/mechanic committed a blunder by opening a high pressure vessel containing hot gases and corrosive materials. There is no verifiable evidence any where in the world that it happened, occurred, or could be duplicated outside a laboratory experiment. This is similar to spreading radiation exposure while doing atomic fusion in your garage. It takes specialized setting, equipment, and knowledge to produce such material from a Viton o-ring. I was a engineer/scientist in my previous life and worked for some of the biggest chemical companies like DuPont.

Just put on your latex or vinyl gloves next time you work on your car. There is nothing to worry about exposure to HF from our cars. There are more important things to worry like getting your car to run and start all the time. Relax and enjoy life.

Tony