Exposure hazards of particles and volatile organic compounds emitted from material extrusion 3D printing
https://www.sciencedirect.com/science/article/pii/S0160412023005895
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Thanks for the info. I was aware of a few, but I didnāt imagine that there were so many VOCs released from FFDm, and I was also surprised by specific filament results, especially PETG.
Besides avoiding inhalation (not always possible) and setting up forced flow extraction with an active carbon filter, I am unaware of other simple and effective measures.
Almost seems like it should be illegal to sell a printer without legitimate filtration. I bet bambu is even worse because it prints at the high end of temps to support the speed.
Imagine how many people think theyre safe because of ācarbon filtrationā lol
Well, itās the filament thatās really the problem, the printer is just the ādelivery systemā. 
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The higher than normal temps might actually be a positive. Chemicals are weird and do weird stuff at different temps.
So higher can be worse, or better.
āThis work has shown experimentally that VOC emissions from plastics increase with temperature, owing to the migration of chemical compounds from the bulk polymer to the surface which then diffuse into the surrounding air.ā
I think its always worse at higher temps. We went from pla at 190c to 220c. Silk pla went from 190c to 230c.
Thanks for this article. Now I know, that Iām happy to have a tinkering cellar for such hobbies and have not to worry about not to have the printer in my home office upstairs.
And thanks to the Bambu Lab concept with AMS, Bambu Studio integration and the better reliability the handling of my P1P in the cellar is much more smoother than it was with the Ender 3 (incl. Octoprint/Klipper) for me as beginner.
I have lately been printing Sunlu white PETG and Prusament grey PETG. I put two different air particle counters near my bambulab X1C printer whlie printing a PETG model, and to my surprise both monitors seemed largely unaffected. In addition, the Airthings device also includes a VOC sensor, and likewise that VOC sensor seemed barely affected also.
and
Anyone else here either found or is using equipment with better sensitivity than mine? I know from having test driven a few different VOC sensors that finding a VOC sensor with high sensitivity is not easy. If anyone has found one, please post.
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I have noticed the same thingā¦
I have one of those IKEA air quality monitoring things and even if I put it inside the printer it hardly measures anything.
Start cooking some food however and is goes up like crazyā¦
Seems to me if you normally ventilate a bit it is not too serious all togetherā¦
^^^This.
Yeah, itās hit r miss as to whether any given chemical molecule in the air will trip an alarm, . On the other hand,as long as whatever it is can scatter light, then hopefully the particle counter will be able to announce that there s something in the air even if it doesnāt know exactly what it is.
I would love to see study data like this comparing the scenarios of an open frame fdm printer, an enclosed printer like the X1 with minimal exhaust filtering, an enclosure with a bento box doing recirculation filtering, and an enclosure with exterior venting.
I run an AirGradient AQ meter that sits next to my printer to monitor small particles and VOCās. I capture the data in a Home Assistant server so I can easily see whatās happening in real time and trending over time via history. I only really have results for PLA and ASA, as thatās about all Iāve been printing with recently and Iāve had my meter for a few months now.
From what Iāve seen, small particles donāt appear to really increase much if at all while printing PLA, closed door or open. It might during a long print, as it has more time to move around the air, but honestly shouldnāt be an issue. ASA results are a bit different, as I typically see a spike in small particles at the beginning of the print that quickly drop off and may increase over a long print, this is with door closed.
VOCās on the other hand can be difficult to track and measure. The issue is that there is always some level of VOCās in the air at all times. There are many daily things that can cause the VOCās level to rise such as: cooking, furnace kicking on, cleaning build plate with rubbing alcohol, having a late night glass of whiskey, or eating way too many beans for dinner. All jokes aside, the last one is the one that gives me the most headache, as it can really mess up the numbers if you arenāt mindful of your personally generated VOCs.
Since VOCs are always in the air, a meter typically canāt give you meaningful numbers like a particle detector. In order to give you results that you can use, the VOC sensor acts more like a nose, it āsmellsā the air and lets you know when smells change. Think of it as like a human nose, it notices smells when you first walk into a room, but over time it quits detecting the ānormalā smells around you. This would be the baseline for a VOC detector. If you light a candle in the room, suddenly you can smell that since itās a new smell in the area. A VOC detector would sense the change and report numbers based upon the rise of this new smell in the area.
My VOC sensor captures the average over a 24 hour period to get a baseline value which is 100. If it drops below 100 then VOCs are dropping below the average, which typically happens if I open a window or run my air purifier. If it goes above 100, then the level of VOCs in the room have gone up, which is what you are trying to look for when printing. This becomes hard to detect since there are so many environmental changes that can have an effect beyond what your printer is putting off.
From what Iāve see so far, VOCs donāt go up at all when printing PLA. VOCs do typically go up while printing ASA, but do not spike like Iāve seen with small particles. I tried to capture these results late at night, furnace turned off, and with me out of the room, which helped give me some values to compare.
Iām still early into using my AirGradient meter and I need to take the time to actually track results in a spreadsheet to better see whatās going on, but Iāve been too busy with other projects. I can definitely say that having good air movement in a room that brings in new air will greatly decrease the saturation of particles and VOCs in the air. If the air in the room doesnāt change often enough, then those levels can rise over time while printing, so you may want to mitigate. I do find that running a bento box in the chamber of the printer greatly reduces the small particles and VOCs I see, sometimes completely depending on what Iām printing. Using my self made vent hose with an inline 65 cfm duct fan completely removes all small particles and VOCs since it creates negative pressure on the chamber and vents it outside.
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Great work!
I think t is safe to say that VOC and particles are not a major concern when 3D printing. However, it is never a bad idea to have good ventilation in the 3D printing area.
I have worked at Philips injection molding department (injection molding of shavers). There is always a smell there. But it is still a place where many people work on a daily basis and I have never heard of anything bad resulting from it. And that is a place where they melt lots of plastics all the time all day every day. And there are a lot of big factories like this.
I personally think the danger of 3D printing is not that great.
Iāve tried a number of different indoor air quality monitors, but I donāt think I ever got clear answers from any of them as to how well they measured the air for particles of size 0.3mm and smaller. I say ironically because itās these smaller size particles that are thought to have the greatest adverse effect on human health, not the larger size particles that seem to be much more commonly measured.
Prior to my acquiring my Bambu Lab X1C, I owned a Prusa Mk3 and an Ender 5, all at the same time. At that time I had the habit of hanging around those two 3D printers and watching them print. I donāt recall noticing anything particularly noteworthy about the air quality during that timeframe, but I would nonetheless often wake up early the next morning with what subjectively seemed like a thin coat of plastic coating the inside of my nose. It can best be described as either plastically, or perhaps waxy. Therefore, I think pretty clearly something was in the air, even if I couldnāt quantify it with instrument measurements. Fortunately, I havenāt noticed this happening much now that I have an X1C, and maybe the reason for the improvement is that instead of hovering over the prints as they developed, I can instead remotely check in from time to time using the X1Cās video link.
A German research institute once commented on this question (in English) two years ago:
Are The Fumes You Smell During 3D Printing Harmful or Even Toxic?
Basically I agree with them, you should always ventilate the room well!
As far as I know, there are still no serious studies on inorganic or organic fine dust particles and which substances have an effect on us. We breathe in, a number of substances, industrial and car exhaust fumes, every day. Composites that evaporate from our household furniture (this sometimes takes decades). Or the cigarette smoke from the person sitting next to us.
And yet none of us walks around with a CBRN protective mask. Because none of this knocks us down directly. In the long term, we will see how much dose makes the poison.
So with ABS and ASA, I wouldnāt want to stay in the room for long. Unless itās well ventilated and thereās only one printer running. (This material can lead to poisoning, even if the printers have filters.)
In PETG, caprolactam is suspected of causing eye irritation and respiratory problems. If the dose is too high. But it is far less harmful and can at least not let us fall over directly, than like ABS/ASA can.
But yes, life is still trial and error.
And I guess we find out.
I hadnāt seen this thread before - calling @PrinterMcgeeā¦
But sensing VOCs with a solid-state sensor isnāt as sensitive as other methods. Youād get much more sensitive results with something like a bento box on the front end to capture and concentrate VOCs, and then do a rapid heat on the charcoal to drive them off for a sensor to detect.
Bosch has some inexpensive VOC sensors that have been optimized for detecting and discriminating between VOCs. There is a developer board that has 8 of those sensors on it for $36 at DigiKey and they can be operated at different temperatures/voltages to preferentially detect different chemicals.
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Long and boring....
I started printing at 30mm/s using 3mm filaments LOL
And back then I mainly printed in Nylon as it was cheap from the hardware store - trimmer line.
Later I preferred ABS.
Learned some vital things in those early years, like how helpful it was to have a noisy printer sitting in a tiny room.
You close the door to have some peace while watching a movie and when you go to check on your print you fall over from the chemical attack on your airwaysā¦
For me it is nothing shocking when it comes to the fumes 3D printing releases.
We know all about since long before 3D printing was invented 
Most people though no longer remember how a NEW car smelled in the old days of plastic becoming popular for the interior of carsā¦
What we today know as the NEW CAR smell is actually just created to hide the smell of what is released from the new plastics in their early months on the roads - go figure, with the new car scent we wouldnāt like new cars at all because they would stink like a chemical factory on a hot day.
What I do find shocking though is how badly the consumer is mislead.
PLA advertised as organic and eco friendly - even silk ROLF
Not even plain uncoloured PLA is free of additives, which are the stuff responsible for the fumes and so called VOCāsā¦
Nylon and PETG advertised as the ideal filament for strong and lasting parts and only very few manufacturers/sellers try to make clear how vital ventilation of air filtration is.
Now there is even studies attempting to ban 3D printers from homes with children and educational environments unless the print environment complies with their recommendations - overkill much ?
Not really once you consider how harmful those Vocās are for the developing bodies and brains of little kids.
We all know how and why 3D printing started but what about the filaments ?
The one problem we had ever since 3D printing became a thing was the filaments we had available.
First it was the total lack of dedicated filaments for 3D printing, later our need to have more colours, more materials - but was it REALLY us demanding this or was our demand created by making more colours and materials available for us ?
When I started colour did not matter because for a decent result we had to sand and paint our models anyway.
So probably not too many people know about the Scotch/3M story about the magical 3D printing filament that never came to beā¦
Back in the day and under the 3M company blanket Scotch had great ambition for the professional 3D market.
Providing speciality filaments for engineering prototyping and such.
Only problem was that their costly 3D printer totally flopped before it even reached the production stage.
Outrun by the competition.
They still provide some special needs filaments but the one filament we were all waiting for was kept under patent protection ever since.
And once the patent was getting due to run out it was changed and renewed to now be protected as a material for their adhesive films.
What was or would be so special about this material?
Bowden systems ruled the 3D printing world back then and they wanted something avoiding all the problem going along with these long tubesā¦
A thermo setting polymerā¦
Hmm, isnāt that what most filaments are today anyway?
Close but not close enough.
You see, their stuff would be like āsoftā ABS off the roll, quite slippery, quite flexible but with little to no compression.
The heating breaks up those long polymer chains and when it cools down the shorter chain segments interlock and become a rather rigid material with a great impact resistance and flex.
Probably close to how TPU95 is in terms of feel, flex and rigidity but without any produced Vocās or adhesion problems like other materials as it literally all melts together to form a new material.
Today we could long enjoy filament near ideal for all general use purposes and higher need filaments with far less harmful content that what we can find for our printers.
But these materials all come at a price and as long as the alternatives are still cheaper and more accepted there just isnāt any money to be made.
Imagine the outcry if there would a a study just covering the US of A to highlight how many printers are used in homes and to how much their average filament use translates in terms of harmful chemicals releasedā¦
California would probably ban 3D printing ROFL
Right now though we are in a total legal loop hole that has no bottom.
Letās say you turned your hobby into a business and have a basement full of printers securing your income.
And years down the line you start to experience more and health issues that eventually some doc links to your printing habits.
Who would you blame, who would you try to request compensation from ??
The printer manufacturer because they did not make it clear enough that using their products might harm your health?
The filament manufacturer because they failed to disclosed the harmful chemicals their filaments produce when being printed?
The shop selling you it all because they did not warn you enough and did not push you hard enough to invest in proper filtration systems and devices to measure possible harmful chemicals?
No matter who you want to take to court you wonāt even get a case out of it.
Only once more than enough people tried to do the same there is a chance for a class action law suit or similar.
But who could the court blame or prosecute after so many years of the industry and government failing to step in ?
In the end it again comes down to common sense and thatās what any good judge would tell you.
You knew the plastic melts, you knew it stinks, you knew you kept getting headaches and worse - so why did you not use common sense and let fresh air through ā¦
Something nobody has mentioned trying is collecting particle samples on some sticky tape and then looking at it under a microscope. From what Iāve read, 0.2 micron is the limit of whatās visible, so maybe with a microscope camera you could see 0.3 micron particles, and larger of course.
Just an idea. Not sure how practical it is, but for some people it might make the topic more real if they could see the stuff theyāre breathing in. Iāve read some sketchy studies that even without 3D printing, thereās a wide range of estimates that something like, on average, 29 to 250 grams of microplastics get into our bloodstream over the course of a year, without any clear mechanism for dealing with it and with as yet unknown consequences.
They say new car scent is actually the smell of all the different plastics combined together. That smell lasts years
I think itās more a perfume they add to mask the scent of the plastic. You can get "new car scentā in a spray bottle, after all.
Over time, your car windows will develop a haze on the interior side that needs to be cleaned off. That haze is the condensation of the volatile organic compounds being āoutgassedā by the plastic in the car.
The windows in your house haze for the same reason. Common things like carpet are made from plastics that outgas, too.
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