3D Printing Fumes are Toxic (sorry!)

Oh boy, am gonna get a lot of flak for this one... Quite a controversial topic in the 3DP community, with most opinions apparently along the lines of:

  • "PLA / PETG don't smell too bad. That's fine"
  • "Been printing PLA for years in my house with no issue"
  • "Room ventilation is only needed for print farms" (or growing weed 😂)
  • "Hasn't been studied much, science is not in yet"

In other words: no big deal. That was my stance as well, after a few months printing PLA and casually perusing 3DP posts on the topic. I felt as safe as the father on a Reddit thread who wrote about his kid printing daily in her bedroom. Which received many encouragements.


Then I stumbled on Reddit threads sharing chilling health stories from folks who had set up printers in their office room without ventilation. Some landed in the emergency room.

This led to digging up studies on 3DP emissions and realizing that, actually, science has spoken. Countless health studies have been conducted that investigated many of the substances incidentally also emitted by 3D printing.

Some are carcinogens, some are endocrin disruptors. Most are volatile organic compounds (VOC). Some end up as ultrafine Particule Matter (PM) in the air. Some smell bad, some smell nice but are toxic, most escape our olfactive sense.

But, fortunately, US agencies like the NIOSH, OSHA, CDC or EPA have issued guidance, standards or regulations on many. Same in Europe.

So I swear that, although I am no Chemist or Environmental Engineer, nothing was made up in this post. So please... 😅

 

Now, once aware of the risks, we can assess our personal exposure via monitoring devices, and develop mitigation techniques (for more on those see the posts listed at the end).


This said, this post only covers a minuscule body of information on the VOC & PM science, standards and 3DP studies out there. And again, I am no specialist in these fields. So, despite the authoritative references provided, feel free to walk away thinking:

But hopefully it'll scratch that topic's surface just enough that a parent may now think twice before setting up a 3D printer in a kid's bedroom for daily use ?

 

By the way, if actual specialists in the field happen to read this, I would love to hear your take or get more pointers.

Happy printing to all !

 

3D Printing Emissions

Hmmm, how can one not like that light roast nutty smell when printing PLA ? Always got my creative juices going !

Until I read what emissions printing PLA actually produces:

This table is from the 2023 study Exposure hazards of VOCs & PMs emitted from extrusion 3D printing. High level summary on 3Dprint.com.

I was gobsmacked to learn that even PLA also emits Benzene, Styrene and Formaldehyde !

Sainte Choucroute, our noses are completely ill-equipped to detect pollutants... So yeah, we'll definitely wear respirators in the house from now on 😂


So that's it ? 3DP is slowly killing our loved ones and you should send your printers to me for 'safe disposal' ? 😂

No, what many of these studies show is that personal exposure is actually all about:

  1. Amounts emitted
  2. Mitigation
  3. Concentrations actually experienced by the user

Not much can be done about (1) for a given filament and printer model. But (2) & (3) can definitely be addressed via techniques like monitoring, enclosing, filtering, exhausting, etc. Some of which are covered in the posts listed at the end.


 

Exposure Standards

It appears that many of the substances emitted by 3DP have already been investigated for decades, and that some have been classified as toxic.

In the US, the National Institute for Occupational Safety & Health (NIOSH) published regulations many moons ago on the maximum permissible concentration in the air for many of these substances. Corresponding regulations have been in place for decades in industries such as Oil&Gas, Pharmaceuticals, Chemicals Production, etc.

The NIOSH Pocket Guide To Chemical Hazards lists the Permissible Exposure Levels (PEL), as well as the proper personal protection equipment (PPE) to reduce exposure. It covers many of the substances emitted by 3DP such as Benzene, Styrene, Formaldehyde, etc.

Across the Atlantic, in Europe, various bodies emit recommendations for Occupational Exposure Levels (OEL), like the Scientific Committee on OEL. The European Commission then emits directives, like this 5th one.

Also noteworthy are the Consolidated Indicative OEL Values (2009), and the German GESTIS substance database that tracks limit values across nations (type in Benzene for example).

These limit values can be used to check how healthy or risky our printing environment is, and tell us if mitigation actions like filtering or ventilation should be considered.

 

For that, adequate detection or measurement is necessary. VOC & PM sensors have become much more affordable, available and reliable in the past few years. They are still far from perfect compared to laboratory techniques such as chromatography and spectroscopy that can detect specific molecules, but they can now provide a broad feel for overall emissions.

Cheap monitors are now available from many stores, like Amazon. Although there's a confounding zoo of devices, a few folks on youtube sometimes do an ok job reviewing them. Examples: testing multiple air quality monitors in an emissions enclosure or Best Air Quality Monitors 2024

 Update  And I have since developed a PM/VOC/COx/NOx/T°/RH monitor & datalogger. It is programmable, and upon high levels of exposure will be able to automatically trigger corrective actions like turning on ventilation, controlling a DIY 3D printer's active carbon filtration system, etc.

 

All these obscure and terse regulatory standards can feel overwhelming, I know. But again...

 

 

Additional Research on 3DP Emissions

There is an ever growing number of studies focused on hazardous emissions from fused deposition manufacturing (FDM) 3D printing. Examples:

Characterization of VOC emissions from consumer level material extrusion 3D printers

Characteristics of nanoparticle formation and hazardous air pollutants emitted by 3D printer operations

Pollutants Emitted from 3D Printers onto Operators

Characterization of Ultrafine Particles and VOCs Emitted from a 3D Printer

Emissions of Ultrafine Particles and VOCs from Desktop 3D Printers with Multiple Filaments   

Real-Time Exposure to 3D-Printing Emissions Elicits Metabolic and Pro-Inflammatory Responses in Human Airway Epithelial Cells  (note: although the results seem pretty scary, we'll need to see reproduction by other teams, and better understanding wrt correlation with actual human exposure in a 3DP environment)


 Update   Great summaries of the results across research studies, also covering mitigation techniques to reduce personal exposure:

UL 200B Guidance Document - Safe Use of 3D Printing for Institutions of Higher Education

3D Printing Air Quality Roundup for 2024  by Aris Alder. Could be considered biased since the site sells filtering, ventilation and PPE products, but all the study / research sources used are listed.

3D Printing Fumes & Air Quality – A Practical Guide by Ile Kauppila

3D printers are worse than I thought. Time to do something about it! video (Sep'24) by Thomas Salander. Not sure if his low PLA & PETG results actually reflect their true emissions, or just the limitations of his sensor selection. Will see in my own testing in the coming Part 3 - Results post from the series below 🤔

 

Also, note that although this post is focused on FDM, similar studies have been conducted on desktop resin printing (SLA) as well.

 

Being aware of the risks is the 1st step toward positive action. But I know, science or not, nobody likes to hear bad news about our cherished 3D printing hobby. So there, am now resigned to my fate... 😂

 

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 Update   Other posts in this blog's Air Quality and 3DP Emissions series:

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