PTFE - Acceptable synthetic?

[zymos]

Zymos, I did mis-speak, I meant the PET spirit bottles. I do have an HDPE drum for a fermenter, but just don't trust it for high-proof spirits. Maybe Chemist could do a test similar to the one he just did on the PTFE. I think heat and vapor would have an adverse effect.
I have a racking cane made from PET, has never seen more than 12% wash or more than hot tap water. The thing is severely crazed (fine checkering cracks) after use and cleaning on maybe a dozen washes.

Fair enough, I'm just saying that it is very common in the commercial distilling industry to store hi proof food grade, USP alcohol in plain old HDPE.
I of course am not recommending any body to actually do so...

[Centimeter]

That’s good enough for me! I’m glad I don’t have to run anything as it’s a bit hard for me to get access to the GC/MS. A couple notes though:

We couldn’t do any studies of metal susceptibility with a GC/MS. Everything’s got to be in the gas phase before it hits the MS. I certainly won’t be putting any metal salts on the LC/MS. My boss would kill me. And actually it’d be a little hard to get the detection range down that low.

From what I was looking at on Wiki, what we’d really be concerned about is PFOA used in Teflon synthesis. Its boiling point is 189–192 °C so it should have had a nice distinct peak if it was present. If you didn’t find this on your GC/MS runs, it sounds like we’re in the clear. Minus pyrolysis products, which shouldn't start forming until well beyond the temps of our stills, I can't think of anything else to look out for.

I just want to say that this is at your own risk too! If you’re really that concerned about it, take a look at the composition of PTFE and see if you can convince yourself of its safety.

I really appreciate your runs Chemist! If you can pull some on some tape that would be amazing. If and when you do run some tape, try and pick a really common brand so we can all use it. Once again thanks!

[The Chemist]

Hey centimeter--My temp program runs up to 240C, so PFOA certainly should have shown up, if present.

I boiled up some tape late this afternoon. I'll run it if I have time tomorrow.

[evilpsych]

Wow. This is getting good! I like it so far on PTFE.

However, I do respect the views of the more conservative mods. A excellent rule for the novice category should be Stainless/Copper/Silver-Tin/Flour... once they've caught up on all the technical aspects of the materials, then they might go on to utilize PTFE or other materials after researching thoroughly and making an informed decision. A good example is Cork. Folks think all cork is the same, even the vulcanized stuff at the auto parts store (which is why i didn't include it in the list) The worst thing about hobby distilling are the morons that do all the wrong things - lead pipes, galvanizes/aluminum boilers, vinyl, pvc, etc

[Ugly]

There is nothing inherently wrong with an aluminum boiler... it just pits like hell and is a crappy choice since it's can't be soldered and requires a fairly decent tig to even weld it worth a poop.

[HookLine]

Thanks for you input Chemist. We may not yet have a definitive answer for each PTFE product, but we at least know that basic PTFE is safe. One step at a time.

[theholymackerel]

I must say I'm rather impressed with this thread in general.

1) We are gettin' GOOD info.

2) No-one has lost it yet and exploded all over the thread.

Keep it up guys. As long as bad info doesn't get posted, and folks play nice I'm willin' to be drug into the 21 century. (I'll keep the kickin' and screamin' to a minimum )

[The Chemist]

Alrighty...after some behind-the-scenes consultation with cm, I did a little tweaking (raised detection limit to 400 m/z, for those interested...) and gave some tape "the treatment". Still nothing. Looks "safe" to me.

It should be noted, however, that I don't have time or inclination to do a well-controlled study of this. So, take it for what it's worth to you, and don't blame me if you die!! As always, I make no recommendations or advisements, and accept no responsibility for anyone's stupidity but my own.

[minime]

My ball valves and I, thank you ever so much Mr Chemist

[rad14701]

Thanks, The Chemist... I think we're all grateful that you have taken the time to do this testing even though we are aware that the results are not certified in any way... Sure beats the old by guess and by golly mentality... While we may tend to err on the side of caution, which I feel is the best method, receiving even unofficial news that a material is relatively safe is always a bonus, at least to me...

[HookLine]

My ball valves and I, thank you ever so much Mr Chemist

Must. Resist. Temptation. For. Obvious. Joke.



And thanks Chemist. Like Rad said, even with your disclaimers, this is still way better than ignorant guessing by the rest of us.

[junkyard dawg]

My ball valves and I, thank you ever so much Mr Chemist

i'm cheap...


I guess GCMS stands for something other than that chromatography thing....

[evilpsych]

My ball valves and I, thank you ever so much Mr Chemist

i'm cheap...


I guess GCMS stands for something other than that chromatography thing....

Gil's Corn Mashin' System. Yours for only 4 E-Z payments of $29.95
(Gas-Chromatography/Mass-Spectrometer)

Someone might be able to do a metal test with a XRD or XRF gun like they have at some junkyards for sorting alloys. take a sample in in a glass jar, and shoot it through the open lid. Might be interesting.

[Tater]

What brand and type was tested? And what does it take to complete the test to where it can be recommend or not to use?

[Ugly]

Not to be contrary, but I'm going to be... no matter who certifies something safe it's still up to the individual to make the choice. If you feel personally as a distiller and human being that there's enough data to support you using a product, then use it. Don't take anything you read at face value, review the data, the results and try to verify it elsewhere. Make up your mind and live or die with it.

I'd not blink twice at using year old PTFE as a personal choice (that I'm also not recommending to anyone in the spirit of CMA) . Metal on metal is the safest bet.

You want some fun- take a year old pure cork gasket and stick it through a biological and GC/MS analysis in comparison to a freshly cut and pressed piece out of the steamer.

[evilpsych]

Not to be contrary, but I'm going to be... no matter who certifies something safe it's still up to the individual to make the choice. If you feel personally as a distiller and human being that there's enough data to support you using a product, then use it. Don't take anything you read at face value, review the data, the results and try to verify it elsewhere. Make up your mind and live or die with it.

I'd not blink twice at using year old PTFE as a personal choice (that I'm also not recommending to anyone in the spirit of CMA) . Metal on metal is the safest bet.

You want some fun- take a year old pure cork gasket and stick it through a biological and GC/MS analysis in comparison to a freshly cut and pressed piece out of the steamer.

Exactly. Hobby Distilling is certainly full of guys who are going to do it the way they see fit regardless of the 'potential' risks involved. Thousands have been harping on things like cigarettes for decades, yet people - knowing full well the odds of death, cancer, etc.. still smoke up every day. We also have to remind ourselves that the end product we're making (no matter how PURE) is still a poison in and of itself. I suppose if you wanted to reduce every bit of potential risk from your hobby, you could NOT DRINK the stuff ...or not do it at all. But life would be boring that way, and it's really short. To temper this somewhat - I have several young kids, all producing their own brand of disagreeable substances, of which, at some point, i'm 100% positive i've ingested. Has it killed me? NO. Do i continue to come in contact with it even though it might shorten my lifespan or cause health problems? Yup.
</soapbox>

anyway. think thechemist could run some store bought against a homemade batch with teflon in it and see the nasties comparison again?

[GingerBreadMan]

I believe that no matter what, there will always be someone that will come up with one more test idea, to prove that since not all tests have been done, it's not 100% proven.

[evilpsych]

I believe that no matter what, there will always be someone that will come up with one more test idea, to prove that since not all tests have been done, it's not 100% proven.

Nothing is 100% 'Proven' or 'Provable' just.. 'beyond a reasonable doubt' I suppose the first OJ trial was a result of that....

[GingerBreadMan]

At some point you just have to say to yourself... hmmm, there are more studies out there that say distilled alcohol is bad for you - with or without the PTFE tape?

---------------------

This reminds me of another thread a long time ago about storing your likker in bottles and what bottles are safe. I found it amusing when store bought liquour bottles (the glass ones) where deemed unsafe because there was some unknown material on the lid. At that time I quipped I use kryptonite lids for my bottles.

Remember, we're drinking distilled alcohol = bad for you, there is no medical study that says it's healthy!

[evilpsych]

Remember, we're drinking distilled alcohol = bad for you, there is no medical study that says it's healthy!

Except as treatment for methanol/isopropyl/otheralcohol poisoning or disinfecting cuts

[GingerBreadMan]

Ahhhh.... so I just have to remember to poison myself with methanol/isopropyl/otheralcohol before consumption

[HookLine]

Remember, we're drinking distilled alcohol = bad for you, there is no medical study that says it's healthy!

Except as treatment for methanol/isopropyl/otheralcohol poisoning or disinfecting cuts

I get that all the time, have to be treated nearly every day. Fine home made rum seems to work best for me.

Must be working, I'm still alive.

[stillvodka]

Everything nowadays has a government exceptable limit, would this apply here with PTFE, The government in my Country still ALLOW food stuff and beverage Refreshment drinks 'Lemonade' that has known cancer causing chemicals, which has been outlawed for sale in the USA and Scandinavian countries, There was a thread running on here a few years back, where people were happy to pour a SPIRIT drink from a PLASTIC bottle.

[Tater]

Reckin it boils down to what are your acceptable limits

[riff42]

damn plastic discussions......

I scanned some, and saw someone mention PEEK.

Suuuuure, it might work, but it's a crystalline plastic, and very very brittle. There are tubes, but those are almost to replace metal lines, not flexible plastic ones. Even if FDA approved, I would do tests first. I'd stick with PTFE. Which, is still not overly flexible as a tube....at least not the one I use....could be useful for something I guess.

[stillvodka]

I Found this on my computer, cant remember saving it , it was by a guy went by the name of 'SWAG '


This material was accidentally discovered in 1938 by Dupont chemist, Roy Plunkett while working with Freon gasses, and has been widely used since. Many of you know this compound by it’s registered trade name of Teflon. Otherwise it is simply known as PTFE
Virgin PTFE is chemically pure and inert. It contains no additives such as lubricants, stabilizers, plasticizers or antioxidants that can contaminate process fluids. This means it cannot leach anything onto a solvent, such as alcohol.
PTFE exhibits excellent retention of properties after a long period of time, even at elevated temperatures and in the presence of oils, solvents, UV light, oxidizing agents and other environmental agents. In other words, it holds up to abuse rather well
PTFE is inert to microbiological and enzymic attack because the pure polymer does not provide any nourishment or porosity for these growths.
It is also tasteless, nontoxic and odorless.
PTFE has a working temperature range of -392F to 572F (-200 to 300 C)
Here is some additional information

Polytetrafluoroethylene (PTFE) shows a remarkable chemical resistance and it is insoluble in all known solvents. It is attacked only by molten alkali metals and by fluorine at high temperatures. PTFE is incombustible and may be used up to 260°C (300°C for short periods). PTFE's coefficient of friction is extremely low and it shows the effect of self lubrication with constant mechanical properties which makes it particularly suitable for bearings, joints, O-rings, stirring bars, hazardous materials bottle pouers, syringes, crucubles, evaporating dishes etc. PTFE may be shaped by compression and sintering into bottles and beakers where its chemical stability and non-wettability make it suitable for use in extreme circumstances.
http://www.dynalabcorp.com/technical_info_ptfe.asp" onclick="window.open(this.href);return false;" rel="nofollow

TECHNICAL DESCRIPTION
PolyTetraFluoroEthylene is a fluorocarbon-based polymer and is commonly abbreviated PTFE. The Teflon® brand of PTFE is manufactured only by DuPont. Several other manufacturers make their own brands of PTFE which can often be used as substitute material. This fluoroplastic family offers plastics with high chemical resistance, low and high temperature capability, resistance to weathering, low friction, electrical and thermal insulation, and "slipperiness".

* Strength (high strength-to-weight ratio)
* Chemical inertness
* Biocompatibility
* High thermal resistance
* High chemical resistance in harsh environments
* Low flammability
* Low coefficient of friction
* Low dielectric constant
* Low water adsorption
* Good weathering properties

PTFE has exceptional chemical stability, exceeding noble metal(gold and platinum), glass, ceramic, enamel, special steel and special alloy. It can resist various strong acids, strong alkalis, strong oxidants and organic solvents even at high temperature. In boiling nitrohydrochloric acid, and in ketone, ether, alcohol, halohydrocarbon, etc. PTFE remains virtually unchanged in weight and properties. Uranium fluoride used in nuclear industry also cannot effect a change on PTFE.
http://www.chenguang-chemi.com/PTFE.htm#chemical" onclick="window.open(this.href);return false;" rel="nofollow


Resistance to chemical agents:
PTFE is practically inert against known elements and compounds. It is attacked only by the alkaline metals in the elementary state, by Chlorine trifluoride and by elementary Fluorine at high temperatures and pressures.

Solvent resistance:
PTFE is insoluble in all solvents at temperatures up to about 300°C. Fluorinated hydrocarbons cause a certain swelling which is however reversible; some highly fluorinated oils, at temperatures over 300°C, exercise a certain dissolving effect upon PTFE.

Teflon® Labware:
Alternative to Glass Labware Beaker. Laboratory analysts are recognizing the utility of Teflon® Labware, as a stand-alone alternative to glassware or as a liner for glassware. Teflon® Labware is better then Pyrex (borosilicate) glass, because it will not break and is less contaminating.
These chemically inert, non-stick, electrically insulated, and temperature resistant devices provide the following unique benefits over traditional glassware:
- non-stick and adhesion resistant for easy cleaning
- non-porous with a smooth surface
- transparent
- chemically inert surfaces
- pliable and unbreakable
- extreme temperature resistance
- resists all chemicals except molten alkali metals and fluorine http://www.welchfluorocarbon.com/TeflonLabware.htm" onclick="window.open(this.href);return false;" rel="nofollow

Thermal stability
PTFE is one of the most thermally stable plastic materials. There are no appreciable decompositions at 260°C, so that PTFE, at this temperature, still possesses most part of its properties.
Appreciable decomposition begins at over 400°C.
ADVANTAGES OF PTFE
Excellent electrical properties
Heat resistance
PTFE is capable of continuous service at 500"F.
Toughness and flexibility
Chemical inertness
Low coefficient of friction
Zero moisture absorption
Weather resistance
PTFE is completely unaffected by outdoor weathering.
Samples exposed in Florida for over ten years are completely unchanged.
APPLICATIONS:
Food processing
Electrical parts
Coaxial cable connectors
Terminal insulators
Transformers
Relays
Medical industry
Washers
Gaskets
Flanges
Valve components
Pump Components
Baffles
Seals
Bearings
Rings
Bushings
High heat applications

[Tater]

'SWAG '/Uncle fred was a troll we had on here a while back

[stillvodka]

Well, I suppose the clue was in the user name, Some Wild Ass Guess

[snuffy]

This will probably keep coming up, so here are a few things to keep in mind:

Things can be proven to be unsafe, but they can't be proven safe. It's like proving there aren't any tigers in Peoria, the absence of evidence is not evidence of absence. And there might be a zoo in Peoria, so all the evidence about tiger habitats could be not to the point. But staying out of Peoria because there's a tiger in the zoo might seem a bit over the top.

Where there is evidence of possible risk, it needs to be evaluated. Back some years ago, there was a huge controversy about possible health effects of high voltage power lines. There were even some epidemiological studies showing a possible correlation. After years of research, the epidemiology turned out to be related to other things that also occur where there are power lines, but the controversy continues to pop up because of the earlier studies.

It might be most useful to think of it in terms of relative risk rather than absolute (and ipso facto unprovable) safety. Anything with a known or suspected risk, try to find a better substitute or change the design to allow other things to be used instead.

Skinning cats is easier than herding them. (Spoken as an old cat herder...)

[Centimeter]

Hmm, after reviewing this thread a bit I see that there is an error in this analysis. PFOA, which is what we were primarily concerned with, has a molar mass of 414.07g/mol. The Chemist had his detection range max at 400m/z (I thought for sure I told him to set it higher). I should have caught this earlier! See, the problem is that this chemical could very well only pick up a charge of +1 (Thus z=1), resulting in an m/z of 415.07m/z. Since The Chemist's detection range was set to a max of 400m/z, this ion would not have been detected if only charged to +1.

I apologize for not catching this earlier!

Alright, I guess I'll run some LCMS on teflon tape.