this post was submitted on 07 Jul 2023
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[–] sudo22 38 points 1 year ago (2 children)

Not really. Truly no printed plastic is food safe due to the pores created during the printing process. These pores can house hard to clean bacteria.

There are coatings you can use to eliminate pores that are food safe. But I’m not familiar with them so I couldn’t really point you in the right direction sorry.

[–] Chocrates 4 points 1 year ago

Yep I have heard this too.

[–] p1mrx 4 points 1 year ago* (last edited 1 year ago)

It is possible to smooth PLA using ethyl acetate, but I don't know if that's good enough for food safety, plus you have to remove the ethyl acetate itself.

PLA won't survive in a dishwasher. PETG might, but there are no reasonable solvents for smoothing PETG.

Maybe it'd be best to print a mold in PLA, smooth with ethyl acetate, clean thoroughly, and then pour silicone into the mold.

[–] [email protected] 16 points 1 year ago

are we starting this meme here on Lemmy too? 😂

[–] [email protected] 15 points 1 year ago (1 children)

technically, yes, but the danger lies more in that food can get stuck between layer lines and develop naughty bacteria

This guy on YouTube explains it great

[–] fhein 9 points 1 year ago

I think even technically that only applies to pure PLA, and most filaments will have at least some additive for colour. Usually filaments blended with some other plastic are marketed as PLA+, but I don't think there's any regulation at all regarding 3d printing filament so I wouldn't take for granted that regular PLA doesn't contain other plastics/additives/contaminants. Though even if the filament contains other stuff it still might not be harmful of course.

[–] [email protected] 14 points 1 year ago

So you guys mean if I print my dishes every day and throw them away afterwards everything is fine.

Great.

[–] LasVenturas 10 points 1 year ago (1 children)

Its pretty simple, PLA overall is food safe BUT 3d printing in general isnt without a coating that is foodsafe.

[–] pennomi 1 points 1 year ago

You also have to take into consideration the dyes used in the PLA, which may or may not be food safe.

[–] [email protected] 9 points 1 year ago* (last edited 1 year ago)

Nope. PETG is maybe the easiest "safer" option, but AFAIK there isn't a true food safe filament. Also 3d printed things will basically be impossible to clean without extensive post-processing (including probably needing to coat it in something), so "safer" single use pretty much.

[–] [email protected] 6 points 1 year ago

Only if you are using it as disposable servingware. As you can't really clean it properly. However there's questions about how much heavy metal transfers to the print from a brass nozzle. Best to use a stainless one

[–] [email protected] 5 points 1 year ago

I would consider using PLA for single-use (like a popsicle mold or something) but because of the bacteria concern others have mentioned, it definitely isn’t recommended beyond that.

[–] [email protected] 4 points 1 year ago

You can get PLA that's certified as food safe ( https://filaments.ca/products/true-food-safe-pla-water-natural-1-75mm , for example), but you've still got the geometry issues people have already mentioned to deal with. You have to coat or smoothe the surface to remove the openings between layers, or disinfect somehow between uses—a nice bleach soak ought to neuter the guck in the interlayer gaps. Above all, use common sense.

[–] bigredgiraffe 3 points 1 year ago

As others have said and from what I have read it’s less a problem with the plastic and more about the inability to clean the small gaps between layers on the surface giving bacteria a place to grow that ends up being the bigger issue.

That said Fillimentium makes this PLA blend that is both recyclable/biodegradable and dishwasher safe so you can reuse it (at least according to the rep I talked to at a fest). Thanks for reminding me I have a sample I need to try out around here hah!

[–] rambos 2 points 1 year ago

Ill just say that PLA cant survive dishwasher temps

[–] Waldemar_Firehammer 2 points 1 year ago

Technically yes, functionally no. It can't easily be sanitized, and the grooves created by layer lines is an ideal environment for harmful bacterial growth.

[–] [email protected] 1 points 1 year ago (1 children)

No, no no no!

The biggest reason why PLA is generally NOT food safe is not the micro pores that enable bacteria growth, the problem is compounds on the additives used to tint PLA.

There the PLA resin but then there's whatever random chemical to achieve colour that might NOT be food safe. It could contain traces of Lead or other heavy metals, cancer causing substances and other stuff that is not supposed to be eaten or come into contact with food

[–] [email protected] 1 points 1 year ago (1 children)

Plastic isn't food-safe period

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