How "not food safe" is "not food safe"?

So, it's been discussed in other threads that the only material that's marked "food safe" is the ceramic material, and in order to make something "food safe" an additional "food safe" coating would need to be added to it in a "food safe" process. For items like plates, cups and utensils, where food is going to be in contact with the items for an extended period of time, it would need to be a higher grade of "food safe".

My question is, what specifically do the other materials fail at to not be "food safe"? Are they themselves toxic to ingest (I don't think so, after looking at their material safety sheets, there's nothing about toxic when ingested)? Are they simply hard to clean after getting in contact with food? Do they leech some chemicals into the food? Is it because they slough off into the food (loose dust should be cleaned off in the manufacturing process, but there may be some left over afterward)?

I ask since I see there are a plethora of cookie cutters in the stores already, and I was planning on creating some of my own. But if I get one printed in "strong and flexible", what actual risks am I running using it to cut cookie dough, given that the piece would only be in contact a short time, and the food would be thoroughly cooked after being prepared with it?

Okay, someone check my logic on this: "Strong and Flexible" is the common name for Fine Polyamide PA 2200. Polyamide 2200 is a Nylon 12 compound. The FDA ruling for Nylon 12 resins in contact with food is that it is acceptable as a film (not to exceed 0.0016 inch) or a coating in constant contact with food that is no more than 8 percent alcohol. So that means the material itself is "food safe" except for foods with a high alcohol content, right?

This correlates to the full description on that second link: "PA 2200 is a Nylon 12-based material that has been specially formulated to meet FDA requirements. This specialty material can be used in contact with food and human tissue." There's no detail on what "FDA requirements" it's meeting (the "food safe" requirements, or requirements for some other use?), but the fact that this compound specifically tries to appease the FDA requirements is a good sign!

So, it seems that the only reason Shapeways can't claim that "Strong and Flexible" is "food safe" is because it's not prepared in a certified "food safe" manner (the technicians operating the machines might not have washed their hands, or might not be wearing masks, so microbes might have gotten inside the model itself), right?

Is there an official ruling (FDA or otherwise) to "sterilize" or otherwise "prepare" a material that by itself is "food safe" but has been handled/prepared/shipped in a non-food-safe way? I would think maybe a thorough washing would be enough; I'm thinking of utensils and such that hang on grocery shelves before being bought with only cardboard hangers; nothing protecting the part of the utensil that touches food. Yet they're fine to use after being thoroughly cleaned when you get home.

There are (at least) two issues - one "actual", one "regulatory".
For the "actual" one - the metallic materials (with the possible exception of silver, depending on what it is alloyed with) will be
attacked by food. The "stainless steel" is actually a composite using bronze as a filler to stabilize the sintered iron, meaning some
copper will dissolve from it (not normally a problem, but hazardous for infants and for people with kidney or liver problems). The gold
or silver plated varieties may contain nickel or other elements underneath, depending on the plating process used. The UV-cured
"detail" acrylics may contain unreacted starting material, also they use a wax-like support material that is probably a strong laxative,
if nothing else. The "strong and flexible" nylon one has a very porous structure, so it will harbour a microcosm of its own, once some
nutrients become available.
The "regulatory" one - none of the materials (except the glazing used on the ceramics) will be bought and handled as "food grade",
with all the testing and hygienic processing that would imply.
That said, the worst you could contract from self-printed, unsealed plastic cookie-cutters would probably be severe diarrhoea (norovirus), but
I doubt you would get any official encouragement from shapeways to try for yourself. (Disposing of the cutters after use would probably
be wise - unless you want to risk contamination with carcinogenic mould toxins)

See here in a recent shapeways blog entry what the nylon material looks like under a microscope.

As @mkroker mentioned, and you can see in the video, the printing process used on Nylon 12 ((WSF) creates a "sparse matrix".... the granules of plastic are NOT welded together in a tight configuration. You will notice this if you try to paint it.. it sucks up paint almost as bad as a paper towel.

That means that food particles would become trapped within those spaces. Technically, it might be food-safe ONCE, but you'd never get it clean enough to re-use safely a second time.

Something that "might" work is to try to apply direct heat (flame?) to the exterior surface to melt the surface granules into a smooth skin.. But, I wouldn't expect a lot of luck with the attempt, and I'd want to check it again with a microscope before I used it on food.

Although not certified food-safe, these "prime gray" cookie cutters have worked very well for us.


A lot more suitable for the purpose than laser-sintered nylon. And for the remaining doubts, we coated them with a food-certified lacquer prior to use.

The material is not available here, but over there around the corner.

Just so as the OP does not get confused.

Prime Grey is not a Shapeways Material!

And depending on location, applying a food safe laquer does not mean the the product is food safe if the process of applying the laquer has no certification to say it is food safe i.e. My father can make and sell preserves and pickles as he has a food hygiene certificate. However he would not be able to package said foodstuffs if the packaging had a 'food-safe' coating applied by him to a non-certified packaging as he does not have the required certification to do so (well, he could but the risks and fines would be huge)

Paul
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stop4stuff Modeller for hireShapeways ShopTwitterYouTube​

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Thanks for the blog link, mkroeker; that was very timely! It's also interesting to see how well the super-glue does seal up the surface; there's quite the difference between the two surfaces.

Yes, I noticed the Prime Grey material is for another vendor. Trompevenlo, looks like you've got it figured out for the EU (I'm guessing, since you referred to a German site for your laquer source), though is there someone with deeper knowledge of the US FDA requirements/regulations that can weigh in?

From what I'm seeing there's some requirements that are for "occasional" contact with food, and some that are for "constant". And there's some regulations for the process (stop4stuff mentions a "food hygiene certificate", and a separate certification for making something not-food-safe into a food-safe container). What's the certification that is needed to take something not food safe and coat it with something to make it food safe? Is it easier for an individual to get certified than for a company? Shapeways has obviously had this on the back of their mind for some time, and it's likely a decently complex process to get the company certified, otherwise they would have just done it. Is it just as arduous for an individual? I'd like to actually sell the output of this process (the cookies; as trompevenlo looks to be doing), which is why I'm trying to educate myself on the "official" requirements in play.

I looked into a coating of some kind that would make one of the Shapeways plastics food-safe, and I'm lost in all the options. There's lots of lacquers and lubricants that appear to be intended for the machines that do the food processing, but I'm not finding an authoritative answer for the utensils. Some people have used super glue (probably not food safe at all!) to smooth/stabilize the outside of their strong-and-flexible pieces, and others have mentioned epoxies. For how open the "Strong and Flexible" lattice is, if there were some compound the piece could be dipped in such that it would be absorbed deep into the lattice, I would think that would be nearly foolproof (painting some sort of coating on runs the risk of missing a spot, or being too thin a coat due to the lattice absorbing liquid so readily). What keywords do I need to search for to find an inexpensive epoxy/coating/laquer that could simply be dipped into to coat a piece?

Not so sure if trompevenlo is really producing according to EU/German food laws - s/he is probably
in a gray area, as that gingerbread thing appears to be a very limited run of home-baked christmas
presents for customers of their arts+crafts shop. If they did this on a regular basis, they would probably
have the local Lebensmittelkontrolldienst going all over their kitchen with a magnifier first. That said,
the two-component winery lacquer they used is probably the way to go.

(I would not try the heating method that stonysmith suggested - at the required temperature and in contact with
air, the nylon particles would probably turn a sooty, brownish-yellow mixture of more or less desirable
compounds. And even if oxidative breakdown could be prevented, closing the surface would only be possible
through rearranging of the available material, so it would have to flow and shrink in a probably hard to control
fashion.)

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Agreed.. I definitely was not suggesting the heating as something to be attempted by amateurs, but rather, I was suggesting it only as a possibility for how the items MIGHT be made food safe in a production environment, and I did indicate that it'd have to be tested properly after such an attempt, before it was used for food.

Don't worry.. I've blackened plenty of nylon in my day. <grin> If you do it wrong, you get small specks of black ash floating all over your workroom. Probably not the best thing to inhale.

I had the same qustion obout "food save"
So here my "investigation" results:
The wine an juice industrie seems to use a "Food safe" varnish to Protect there Metal and Wood parts.
In german its called "Kelterlack". Sorry bat I did not find a Englisch translation.
You cann buy it on shops for accessories to make your own wine.

Yes anyone can make 'food safe' products for use in their own home, but for retail or public sale there are so many hoops, loops and certificates to jump through that just suggesting a product that anyone can use is not very helpful to those such as tromevenlo producing ccokies as the only true course of action is to get the correct certificates to protect your back if nothing else.

Paul
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stop4stuff Modeller for hireShapeways ShopTwitterYouTube​

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Hi everyone!
I'm very curios too about this question
I found in the material page "the Strong & Flexible Plastic" the technical .pdf Material Data Sheet from EOS
In their website there is PA 2200
"approved for food contact in compliance with the EU Plastics Directive 2002/72/EC (exception: high alcoholic foodstuff)"
in the same page there is also "PA_2200_Food_regulatory_assessment_07-03_en.pdf"

"the Certificate: Food regulatory assessment of laser sintered" ends with these words:
"From this it can be concluded that articles produced from PA 2200 by the EOS laser sintering process are in compliance with the EU Plastic Directive 2002/72/EC for the use with all types of foods except high alcoholic foodstuff at contact conditions up to 24 h at 20°C."

So if I understand correctly it's food safe if you explain the conditions, and you can in addition suggest to clean (without alcohol) the stuff before put it contact food.

Basically the material might be foodsafe, but the processes in making and handling the finished item are not certified as foodsafe. The surface of Shapewasy 3D printed items made from the material is porous, ideal hiding places for all kinds of nasties - I certainly wouldn't consider eating my dinner from a WSF plate.

Paul

The WSF itself, as mentioned previously, is likely food safe. The item produced from it likely is not. It would be like having a cutting board made of balsa wood. You can use it to cut up tonight's chicken, but would you then use it to slice up the salad after a quick wipe with alcohol? Too risky in my book.

There's more than one way to skin that cat, though. Since you're intending to use the item as a cookie cutter, why not drape the dough with a layer of cling film, wax paper, or parchment and cut the shapes "under" that? (My preference would be cling film for a good barrier.) The tool need not be food safe in that scenario, and the cling film is already intended for food contact. You may need to bunch up the film in order for it not to crush the edges of the cut shape, but I'm sure a few minutes of experimentation should yield good results.

Along those lines, I'd wrap the cutter in plastic wrap or tin foil. I think if you just placed it on the surface, you'd end up tearing the plastic as well when pushing down.

Sounds like a mess to me.

Better to wrap the tool in clingfilm...

Edit: Bah! Too danged slow, again!

Have you thought of Googling 'food safe paints'?

Anything wrong with the epoxy-based winery coatings ("Kelterlack" in German) as mentioned by
trompevenlo and wedge earlier in this thread ? Seems to me this discussion is going full circle...