Study Shows Some 3D Printed Objects Are Toxic | Hacker News Reader

Study Shows Some 3D Printed Objects Are Toxic

ucrtoday.ucr.edu

43 pointstrop15 comments

  But the precise identity of these substances 
  is often unknown to researchers and printer 
  users because the printer manufacturers don’t 
  disclose this information.

That's not entirely honest. That statement conflates the idea that there is no information available to end users, detailing how 3D printing technology works, when the truth is that the information is out there, and most of the materials involved in consumer-grade plastic 3D printing kind of HAVE TO BE well-understood from a chemical perspective in order for the printers to be designed around them.

FormLabs does publish material safety data sheets:

http://cdn.shopify.com/s/files/1/0183/2285/files/MSDS_v7.pdf

So does Stratsys:

http://m.stratasys.com/ig8del/lnk000/=usglobalimages.stratas...

The larger companies DEFINITELY force you into using THEIR proprietary plastics, when open-source printers permit the use of commodity ABS or PLA.

ABS - https://en.wikipedia.org/wiki/Acrylonitrile_butadiene_styren...

PLA - https://en.m.wikipedia.org/wiki/Polylactic_acid

But, realistically speaking, just based on the fact that it's possible to cobble together open-source 3D printers from commodity parts and commodity expendable plastic, should inform the reader that the materials used by 3D printers are not so mysterious. In most cases the materials are acrylic/styrene based polymers, and not so exotic that they haven't been used for decades. Whether they've EVER been safe is another question altogether.

The article neglects and glosses over these details.

The devil is mostly in the details, and enough pigment is in the PLA to somewhat alter printing characteristics. I believe different color PLA has different smells but that is right on (or past) the detection border.

Raw "natural" uncolored PLA is probably about as toxic as a corn cob or piece of wood, in other words it can probably mess up some embryos but its not a serious problem. Its polymerized lactic acid, not exactly biochemically exotic, we're not talking about organometallics here or arsenic chemistry or something exotic like that. It "should" be very biochemically boring.

On the other hand there is a VERY long history of pigments in general being toxic. Add in legendary Chinese safety standards and I would not be surprised if there is a problem with chromium-VI tinted orange PLA. Or white lead pigment in white PLA. Oh I'm sure the press releases will say its all lead free and gluten free and organic free range plastic, but on the other hand I'm sure we all know strange things get shipped and they're not using FDA approved food dye for everything over there.

I was very displeased with the tone of the article claiming ABS (which stinks) and PLA (which is nearly odorless) are very superficially both dangerous and only later in the article do I read that PLA's effect was barely statistically measurable although the other plastic is a highly effective mass murderer. Oh just a slight bias in the article until it comes time to report results, just a tiny little bit of bias. Perhaps they patented that too.

The article neglects and glosses over whether the "melted plastic" objects were ABS or PLA (or something else), which quite readily indicates the useful content in the article. (I suspect the research clearly defined that, but the article comes across as "I need to reach my word limit for the next 20 minutes, so I'll just copy-paste a few scary sounding sentences from a research paper, then make up some filler to go between without bothering to understand anything.")

You appear to be jumping from 'the article is missing some details' to 'the article must be completely wrong'. Impressive!

> She found that after exposing the parts to ultraviolet light for one hour, the parts are significantly less toxic to zebrafish embryos. The UC Riverside Office of Technology Commercialization has filed a patent for this work.

What the fuck. Filed a patent for shining some UV light to decontaminate parts before using them? What the actual living fuck. That is what labs do (and should be doing) ANYWAY for a lot of equipment before starting experiments.

I'm pretty sure its even worse than that. As I understand the UV light is being shined on a block of mostly cured UV resin from a UV resin printer. It seems that the fish are dying because the uncured resin leeches into the water.

UV resins (as used in 3d printers) are often oxygen inhibited, so a derivative work patent could be filed on the combination of UV light in an oxygen free environment (joke).

You bring up good points.

Also, interesting that Carbon3d's CEO, (Carbon3d being 3d printer that indeed works by curing resin with light), from the beginning has been flaunting future applications in biological sciences: http://www.popularmechanics.com/technology/a14586/carbon3d-3...

I feel like there should be a two troughs to the hype cycle: https://commons.wikimedia.org/wiki/File:Gartner_Hype_Cycle.s...

One for the normal disillusionment, the second for discovering that this new hot thing is actually bad in some notable way. And then sometimes we recover from that, sometimes we don't.

I think light-curing 3dprinters will never catch on in a big way, because I can't imagine normal people handling the uncured resins in a safe way on a mass scale.

Article link suggests that much of the bad stuff happened with the stereolithagrphy printers, I hope more research is done on safety of FDM printers. While polylactic acid (safest material that can be used) is basically corn... inhaling burning corn fumes is still probably carcinogenic.

About the PLA fumes - this has actually been extensively studied and there's no notable amounts of decomposition at normal PLA melt temperatures - that is, if there's no visible charring on your part, there's no measurable decomposition fumes. ABS fumes are much more significant, but they appear to be at about the same level as searing meat in a frying pan. I'm sure if you put a zebrafish embryo near frying pan fumes it would be harmed, but that isn't saying much.

In other news, scientist applies for patent on fix for underdone cooked food - "We found that by applying heat we could could..."

While I agree that a patent may not be justifiable, the method of toxicity doesn't appear to be a biological contaminant, rather the material itself (or an impurity thereof). So it's different from the usual processes to sanitise lab equipment.

I read it that way at first too for some reason, but decontamination doesn't only apply to biological contaminants, and he never said sanitize.

That's not surprising for UV-triggered photopolymers. A material that will go from a liquid to a solid with just a nudge from some UV light has to be quite reactive. Here's the Material Safety Data Sheet for one of Stratasys's "bio-compatible" materials.[1] That stuff has to be contained in a cartridge for safety reasons. Once fully cured, it's supposedly safe for dental devices. Here's Form 1's clear material.[2] Lower hazard ratings, but still hazardous.

If the curing reaction doesn't go to completion, some of the source material will remain, which is a problem. If further exposure to UV reduces toxicity, the 3D printing process isn't finishing the curing process.

ABS extruders should produce objects no more toxic than the raw ABS. ABS is rather neutral chemically. When heated, it may give off "irritating vapors", says the MSDS,[3] and its combustion products are toxic, but cold, it should be harmless.

[1] http://usglobalimages.stratasys.com/Main/Secure/MSDS/Dental%... [2] https://www.cs.cmu.edu/afs/cs/academic/class/15294-s15/resou... [3] http://download.makerbot.com/filament/ABS_MSDS_MakerBot_Stra...

Since I carry around some of those UV-triggered photopolymers around in my mouth (dental resin composite), your post alarmed me somewhat. Here is a relevant article from 2012: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3532765/

TLDR: It depends on how well your dentist handles it, and also what compounds are used. There is cytotoxicity and the known effects of BPA, but you cannot find the word "cancer" in that article. And incriminating compounds are reduced over time ("aging").

> If further exposure to UV reduces toxicity, the 3D printing process isn't finishing the curing process.

Then that seems super solvable. There just needs to be an end curing phase added where the final object is exposed to UV for a little while.

If the material is clear, translucent, or thin, that should work. Curing the interior of opaque materials may not work.

FormLabs admits that post-curing may be necessary.[1] But they don't sell a curing chamber. High-power UV curing chambers are not cheap.[2] Some people have reported success using cheap UV sterilizers, but that's going to depend on how thick your parts are. Nail polish curing UV devices are too weak. Real curing chambers look like a microwave oven, with door interlocks and a turntable.

[1] http://forum.formlabs.com/t/recommended-uv-chamber-for-post-... [2] http://www.cureuv.com/uv-light-curing-chambers-and-flood-lam...

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