spallation

[Hippie Dickie]

i was doing some miscellaneous searching on "food grade" tubing, and ran into a company selling a "food grade" tubing that had less "spallation" than silicon tubing. A google or two later and i found this quote from New England Journal of Medicine:

Spalled particles of silicone were observed in the livers of patients with chronic renal failure treated by hemodialysis. The refractile particles of silicone were associated with various degrees of hepatic inflammation and fibrosis, and granulomatous hepatitis was evident in nine cases. Retrospective examination revealed the material in 18 of 38 liver-biopsy samples from patients on hemodialysis who had clinical hepatic dysfunction. Of 31 autopsies of patients who had undergone hemodialysis, 22 revealed silicone in the liver, and silicone was also present in the spleen in all cases and in the marrow, lungs, and nodes in some. Giant cells containing silicone were also observed in these organs. Silicone was present in patients who had undergone hemodialysis for six weeks to 84 months (mean, 24 months). The identity of the material was confirmed by atomic absorption and by electron microprobe analysis. The silicone was traced to a segment of silicone tubing located in the roller pump of the dialysis machine.

This spallation was not due to heat, but to physical action by the pump, which manipulates the silicon to force the blood through the tubing.

The whole concept of "food grade" plastic really bugs me -- while it is difficult, i try my best to NOT eat plastic -- the concept of food safe plastic is an oxymoron.

So, don't flex your "food grade" or "medical grade" plastic tubing.

 

[Konrad_Zuse]

Nice find Hippie, but what should we look for then, and how does this find effect us at vaporists?

 

[Hippie Dickie]

well, it doesn't affect me at all, since i only vaporize through glass.

But my concern, and hence this thread, is that most people think exposure to plastic nasties begins at temperature greater than vaporization temperature, but this finding says that temperature is not the only issue.

i thought other vaporists might be interested.

 

[DevoTheStrange]

so pretty much any excess strain on the tubing can possibly cause a shedding of silicon molecules? Possible micro fractures in the tubing?

 

[Hippie Dickie]

There's a wikipedia article on spallation that demonstrates (animated GIF) the principle

http://en.wikipedia.org/wiki/Spallation

it would appear (from my limited reading on the matter) that flexing plastic is bad.

Also, i read about someone (on OG) who soaked their whip in alcohol to remove the vapor residue and the plasticizers were leached out -- the tube became hard and brittle.

maybe i'm just overly concerned, but then again i don't eat fast "food", either. Like the Food Rule says, don't eat what gets passed to you through a car window.

 

[Konrad_Zuse]

From the wiki page all I see is that it's stressed by some force. We are usiong air, how much could stress it? also maybe it could be stressed when cleaning too?

 

[B.]

well, it doesn't affect me at all, since i only vaporize through glass.

word.

 

[DevoTheStrange]

From the wiki page all I see is that it's stressed by some force. We are usiong air, how much could stress it? also maybe it could be stressed when cleaning too?

Coiling the tubing or bending it is the force that could potentially work.

 

[Konrad_Zuse]

From the wiki page all I see is that it's stressed by some force. We are usiong air, how much could stress it? also maybe it could be stressed when cleaning too?

Coiling the tubing or bending it is the force that could potentially work.

I've bent mine before... the other day actually... GASP!!

 

[onigiri1692]

I hate to bump a really old thread, but seeing as this topic is linked in stickies and the vaporpedia, I thought I would give my two cents to clear up any misconceptions this thread may have created.

For our purposes, using silicone tubing with our vaporizers is as safe as safe can get. The issue of spallation with dialysis patients on the other hand is completely different. These patients are having their blood pumped through the silicone tubing of a hemodialysis machine and back into their body hours at a time on a weekly basis for years...this is a huge exposure difference between using the tubing for our purposes and that of a dialysis patient.

The rate of exposure is critical in instances like this. For example 10 bananas contains roughly the same amount of radiation as a typical x-ray of an arm. (Fun fact: bananas are one of the top causes of false positives for radioactive material at ports and other ways of entry into a country because the potassium in the bananas is radioactive)

The effect of spallation is even worse in the case of a dialysis machine because of the type of pumps used, known as a peristaltic pump. By its nature, a peristaltic pump constantly stresses and bends the silicone tubing throughout its operation as seen by the diagrams below:

While spallation of silicone might seem like a huge issue for dialysis patients, it really isn't, because the people undergoing dialysis are already experiencing kidney failure...so it is death, dialysis or get lucky and have a kidney transplant. The sad fact is, the people in the study the OP cited are patients who had undergone dialysis for an extended period of time (hugely increases their exposure rate to silicone) probably because they were old, could not find a kidney match, or were otherwise not a high priority on the transplant list.

Anyways I hope this clears up some misconceptions

Modnote: There's no rule against bumping an old thread. Good posts such as this are always welcome.

 

[Pcpvapors]

I think the link hippie may have been connecting (and I may very well be wrong) is that when we suck until we look like fishes on our SSV tube, the spallation occurs and may stick with our vapor, much like the blood gets pumped through the hose. Either way something is being drawn through this silicone tube be it blood, vapor, or air and possibly picking up nasties.

EDIT: we've all seen some SSV tubing that looks like it could grow algae or our precious plants so I guess a little silicone couldn't kill us

 

[onigiri1692]

I think the link hippie may have been connecting (and I may very well be wrong) is that when we suck until we look like fishes on our SSV tube, the spallation occurs and may stick with our vapor, much like the blood gets pumped through the hose. Either way something is being drawn through this silicone tube be it blood, vapor, or air and possibly picking up nasties.

EDIT: we've all seen some SSV tubing that looks like it could grow algae or our precious plants so I guess a little silicone couldn't kill us

I get what you are saying. My point is that while little silicone particles may be making its way into our vapor, the scale to which it is happening is nothing compared to dialysis patients who are having the stuff pumped into their blood stream on a constant and regular basis.

And to further provide evidence to backup my claim look at the quote that the OP cites:

"The silicone was traced to a segment of silicone tubing located in the roller pump of the dialysis machine."

This means that unless we are constantly bending and stressing our silicone whips, (like the diagrams above shows happens with the dialysis machine) we won't experience the harmful affects of silicone that dialysis patients do. Normal use/movement of a silicone should be perfectly safe (I only say should because I am not a doctor or scientist so take my statements as you will)

Not to mention the fact that we don't have vapor pumped directly through our blood stream. This greatly affects the bio availability of the silicone particles in a person's body. Meaning that while trace amounts of silicone may make it into our lungs, our body will have a harder time using it to make deformed cells which contain silicone as opposed to the silicone particles floating through our bloodstream.

 

[Pcpvapors]

Well I had an interesting thought while fixing my fridge tonight also, if you have a relatively modern fridge, you more than likely have the filtered water faucet in the door that takes way too long to fill a glass when you have cottonmouth. Anyway, I guess it comes down to were exposed to shit like this everyday on a small scale. Sorry back to the fridge, the water is ran through essentially whip tubing before dripping into your glass, now I'd say this is about as much exposure as hitting your tube. Once again it all comes down to how much you really want to be exposed to.

 

[Hippie Dickie]

@onigiri1692 - i was just kind of blown away by a manufacturer making a point to specify "less spallation". That motivated me to do a little bit of reading. This was a totally new concept to me -- just thought i'd pass it along.

 

[onigiri1692]

@onigiri1692 - i was just kind of blown away by a manufacturer making a point to specify "less spallation". That motivated me to do a little bit of reading. This was a totally new concept to me -- just thought i'd pass it along.

No doubt, I am glad you passed this tidbit along, it also encouraged me to do a bit of research on the subject. Nothing wrong with a bit of good discussion, especially if it has to do with our health

This kind of thing just goes to show you how much we are exposed to chemicals on a day to day basis from not only vaping, but just general things that we do...For example apple juice, who knew so many samples from grocery stores contain large amounts of lead. It really makes me wonder, what is all this low chemical exposure going to do to us in the long run?

 

[vap999]

Air passing over a silicone tubing surface at the wimpy speeds and pressures of inhalationis not going to cause any spaliation. Nor will there be volatilization of un- and partially-polymerized silicone monomer (silicone oil, generally about 40% of silicone tubing, acting as its built-in plasticizer).

Despite its inherent oil content making it distasteful in some respects, e.g., stickiness, silicone tubing is about as safe as one can get, and may be safer than glass for many uses. For example, silicone tubing is used just about everywhere in bioprocessing and biopharmaceutical manufacture, usually connecting stainless steel equipment, while glass is hardly used. Glass has its problems, even that used for high-end pharmaceutical packaging - see http://contractpharma.com/issues/2012-01/view_features/the-glass-quandary/.

Overall, I think PTFE (Teflon being the main branded product line) or perhaps even better, PFA, which is more transparent, may be the best option for vaporizer tubing (but that's a topic perhaps deserving its own thread).

 

[Hippie Dickie]

@vap999 ---- wow. great article. thank-you for bring the glass flaking issue to my attention. i see i need to study glass vials a bit more. one issue is whether laser drilling would be better than diamond bit drilling.

and i'm not even going to think about what drug delivery devices are doing to patients -- too horrible to contemplate. life is risky, eh?

 

[placetime]

Air passing over a silicone tubing surface at the wimpy speeds and pressures of inhalationis not going to cause any spaliation. Nor will there be volatilization of un- and partially-polymerized silicone monomer (silicone oil, generally about 40% of silicone tubing, acting as its built-in plasticizer).

Despite its inherent oil content making it distasteful in some respects, e.g., stickiness, silicone tubing is about as safe as one can get, and may be safer than glass for many uses. For example, silicone tubing is used just about everywhere in bioprocessing and biopharmaceutical manufacture, usually connecting stainless steel equipment, while glass is hardly used. Glass has its problems, even that used for high-end pharmaceutical packaging - see http://contractpharma.com/issues/2012-01/view_features/the-glass-quandary/.

Overall, I think PTFE (Teflon being the main branded product line) or perhaps even better, PFA, which is more transparent, may be the best option for vaporizer tubing (but that's a topic perhaps deserving its own thread).

There is a thread.
http://www.fuckcombustion.com/threads/whip-tubing-all-your-questions-answered.3311/

 

[OO]

if anyone has watched how the pumps work, it isn't hard to imagine that some amount of tubing would be incorporated into the fluid, that being said, is the quantity of silicone being found in the patients of medical significance?

 

[Hippie Dickie]

how much silicone embedded in your kidneys are you willing to tolerate? i suppose kidney failure is end of life anyway, so what's the difference, eh?

 

[t-dub]

ok, as a patient who gets frequent intravenous infusions I have to add one thing. After I get a bag of fluid I can taste the plastic. It oozes out of your pores, your tongue . . . you can taste the meds too but they are distinctly different. Does this mean that there are medical grade silicone bag/tubing molecules running through my veins? Probably . . .

 

[josephaltier]

This probably isn't a serious issue regarding silicone or polyvinyl chloride vape tubing. The kidney dialysis machines use peristaltic pumps that really stress the silicone tubing more than anyone ever would.

 

[Hippie Dickie]

yes, you are right -- it's just the idea of spallation that puts me off of using plastic in any form.

 

[Zangano Cruel]

I wouldn't believe that much in pharmaceuticals either. Pharmaceuticals are just puppies of oil companies. Imagine they are promoting instead of pure glass, new plastics and new polymers, eeewwwww, of course made of oil derivates... It's just hard to believe that. For me that glass flaking whatever bla bla bla is just another attempt for big oil and plastics companies to finally get rid of and important and really easier way for everyone to make glass cointainers, or just plain glass. Can you imagine??? So, from now on we can't drink from glasses, no more beer bottles?? Beer and wine in plastic bottles??? Big bullshit my friends, this is just another conspiracy from the 1% and the pharma-oil companies,they are the same
Keep using glasses and say no to as much as possible to oil derivates and plastics-polymers-silicons whatever.

 

[Zangano Cruel]

I wouldn't believe that much in pharmaceuticals either. Pharmaceuticals are just puppies of oil companies. Imagine they are promoting instead of pure glass, new plastics and new polymers, eeewwwww, of course made of oil derivates... It's just hard to believe that. For me that glass flaking whatever bla bla bla is just another attempt for big oil and plastics companies to finally get rid of and important and really easier way for everyone to make glass cointainers, or just plain glass. Can you imagine??? So, from now on we can't drink from glasses, no more beer bottles?? Beer and wine in plastic bottles??? Big bullshit my friends, this is just another conspiracy from the 1% and the pharma-oil companies,they are the same
Keep using glasses and say no to as much as possible to oil derivates and plastics-polymers-silicons whatever.

Either way, I try to vaporize through glass eiher way, and water filter it. So I guess any glass flake or particulate would stay in the water. Am I wrong here??