3D printer emit toxic fumes survey

Our high school senior design team is analyzing the communities interest in a 3D printer filtration system and health concerns. Can you please answer this quick two question survey to help us out? https://goo.gl/forms/6CzHc7dhP7LejLaI2

Thanks,
Trexation

Edited 1 time(s). Last edit at 08/24/2017 03:41PM by Trexation.

Completed, please search the forums (I'm sure you have) there has been a fair amount of work done on this by users, including myself.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

@Trexation

I would have submitted but you don't have an option for "already have a filtration or exhaust setup"..

I've yet to catch up on the forum's posts on this matter but will be doing so shortly.

I believe there are a few parameters that have an affect on the levels of toxic fumes produced and these are predominately the quantity of polymer being processed, the length of time the polymer stays hot, and the ultimate processing temperature of the polymer. The quoted thermal degradation temperatures of extrusion polymers is often at least 20-30°C above the processing temperature. That said, hold a polymer molten and it will slowly degrade as can be seen in the change of colour, particularly in the non-coloured polymers. A neat trick for the filament producers would be to include a chemical that clearly changes colour if over heated to warn users they have got things very wrong.

Marketing of a product intended to protect our health should be honest, genuine, and informative. Treat the core users with respect rather than going down the Daily Shmail or Scum headline route of "the fumes contain x/y/z mega NASTY long name chemicals that can KILL you" while neglecting to mention you'd have to be sniffing the fumes direct from the hot end for x hours before reaching exposure limits. Yes there will be some nasty chemicals produced but at what point does it become more hazardous than say eating an apple pip (contains chemicals that react with bodily chemicals to form Cyanide), cooking over a barbecue, or the fumes in a car during a motorway commute?

My two pence worth is that enclosed printers are necessary to really control emissions of particulates (UFPs) and volatiles (liek styrene).

You need filtration for the particulates and activated charcoal for the volatiles.

A much smaller/lighter system can be devised which recirculates air from the printer through the filters and back again, as it "polishes" the air gradually inside the chamber rather than trying to clean it in one fell swoop like an exhaust filter system has to. Also presuming some heat in your chamber is desirable returning the air to the machine makes sense, you return the heat with it. Indeed pulling air from the top of a chamber and returning it to the bottom is also desirable.

As most printers are open this type of system has no application.

I settled on a room size air purifier with HEPA/Charcoal filtration which runs whenever printers are running and for some 10 hours afterwards, if possible I open windows too. Most printers are not happy with air blowing over them whilst printing so extractors above machine etc... might be counterproductive.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Thanks for all of the help!
We will definitely consider all of these ideas in our development process. I really like the idea of putting the filtration system in the enclosure to slowly filter the air, though I do have one concern. Our general thought was to make our design solution an after market add-on that could go potentially around the 3D printer in the hopes of ensuring compatibility. My concern with a closed system is that it could heat up the electronics and plastic parts in cheap kits too much, maybe it could be an option for the end user between using it as an open system and a closed system.

I would also like to ask if any of you would be interested in serving as experts or stakeholders(3D printer enthusiast) for our project, there would be a very minimal time commitment. It would be just a few emails a month and it would mean a lot if you could help.

Thanks,
Trexation

Happy to help with the stakeholder thing.

Just to clarify my idea would be an external box with two air hoses, one coming from the printer, placed fairly high up (extraction) , and one lower down (return). Presuming you had enough filtration, you could either open the return and let it vent to the room air, or vent it externally (probably not worth bothering with filters though).

My attempt at this also included a heater to heat the chamber, in the event that there is insufficient heat from the bed or the printer is in a cold location, this proved problematic, but with the right heaters (PTC maybe) could work. The other is that moving air like this takes some thought, I used a hairdryer but it wasn't a quiet unit!

Edited 1 time(s). Last edit at 08/25/2017 06:07PM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Here's what I did..

[www.youtube.com] (have since run the exhaust hose out the window)..

That seems like an excellent solution; I am impressed by your ability to find such a perfect cabinet for the 3D printer and the filament. Does the system completely remove the smell?

Also, Does the venting out the window cause problems with the appearance of the exterior of your house for neighbors or have any leakage issues when it rains? I ask because the room with my 3D printer has one window that faces toward a neighbor who polishes his gutters and asks our family to cut the grass to the same height so the yards match. A solution with something venting out the side of the house would probably infuriate him. Do you think that a vent system could vent somewhere else, perhaps an attic?

Thanks,
Trexation

I think if I had that neighbour I might put the vent there deliberately.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Quote
briangilbert
Here's what I did..

[www.youtube.com] (have since run the exhaust hose out the window)..

I Like what you did. Now just add a standard Chemical and Combination Low-Profile Cartridge Filter to the top.

Here's what I did, I purchased some 65mm Industrial Chemical Gas Mask Respirator filters. about $8.00 for 6 filters
I purchased a Bathroom Ceiling Fan Vent at my local hardware store $ 15.00, and 3D Printed a holder for the Filters $0.013.
Will be hooking the fan up to a light dimmer to control the Speed yard sale $0.50. Now I can exhaust the clean air back into the room.

80mmx80mm.stl

I like your idea and thinking however I think the survey form might be a little misleading. I understand that many filaments release chemicals that have to be removed however you can still buy unmodified PLA filaments designed specifically for use in enclosed spaces. A majority of PLAs nowdays are modified with chemicals to improve their properties, they were originally offered as safer alternatives because they used food grade plastic. You can still find plenty of companies that make filament like this if you do some research.

If you're going to say that all materials release dangerous fumes, you should also suggest users throw away a vast majority of their plastics as the off-gassing is far worse than days worth of printing with clean filament.

Edited 1 time(s). Last edit at 08/30/2017 09:00AM by ohfurryone.

Quote
ohfurryone
If you're going to say that all materials release dangerous fumes, you should also suggest users throw away a vast majority of their plastics as their off-gassing is far worse than days worth of printing with clean filament.

I do understand! However I Lived when they removed lead from gas, raising price per gallon. However lead was an additive and did not need to be removed.
There are many types of filament that have a smell ranging to nauseous and I though this cheap way of removing such smells would be amply rewarding.

Hi are you suggesting they should have kept the lead in gasoline? Ahh I see you mean there should not have been price increase... I see.

3d printing in theory produces toxic volatiles more so with some filaments than others, and ultra fine particles. How much and how risky they are is not well known. Carbon filters can eliminate the odours produced and hepa filters can remove the particles.

It's how you implement it that is the tricky part.

For open frame printers you either:
-Use less potentially toxic materials eg pla, petg, many makerspaces ban abs for example.
-Place the printer in an area such as garage/shed away from people, not alway practical in winter in cold climates.
-use ventilation such as open windows, extractors, vents but drafts are problematic for print adhesion.
-use a room scale filtration device with hepa/charcoal
-minimise the close proximity of people, use cameras to monitor prints.

For enclosed printers:
-have an air exhaust system, either back to the room which needs relatively big filters as there is only one pass, or vent the chamber outside of the building.
-have a recirculating filter system, can be smaller filters. Could be internal ie. Car on-dash air filter systems (not sure how well these work) or an external unit.
-design to minimise heat loss from the chamber by returning the filtered air or only run your filter as part of a chamber cooling system, or as a post print activity.

Edited 4 time(s). Last edit at 08/30/2017 04:09PM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Here is where my exhaust goes, straight out the window..



The fan I'm using for exhaust is a beast.. so no issues at all with exhausing the air, I usually just have it runnning slow, but it's a jet engine if you run it at full speed.
[www.digikey.com]

Thank you so much to everyone who has submitted their input and responded to our poll. We have close to 50 responses at this point which is awesome!
With the amount of feedback received, I think that it would help the community to have the results of our poll.

Poll:
47 Responses at the time of writing

Question 1:
Did you know that the extrusion process for 3D printers emits dangerous fumes in all materials? For example, ABS emits large amounts of Styrene.
Yes - 36.2%
Yes, but I was not aware that toxins are present in PLA - 44.7%
No - 2.1%
I don't care - 17%

Chart of Emissions:


Question 2:
Would you be willing to purchase a filtration system to prevent the inhalation of toxins?
Yes for >$250 - 0%
Yes for $250 to $100 - 6.4%
Yes for $100 to $50 - 19.1%
Yes for <$50 - 36.2%
No, don't have the money - 10.6%
No, don't care about the health risks - 27.7%
--- End of Poll ---

Link to poll: [docs.google.com]

Thank you to everyone that contributed,
Trexation

@Trexation

Just a heads up that a HEPA filter is not enough to deal with VOC's, probably worth trying to track down the paper mentioned in [threedprintingtoday.libsyn.com]

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Co-creator of the Zesty Nimble, worlds lightest direct drive extruder.
[zesty.tech]

He has a room size air purifier with HEPA/Charcoal filtration, his filter is called Active Charcoal.

Charcoal/Carbon:

The carbon air filters still remove dust, pollen and other contaminants from the air, because charcoal is porous, the filter has a very high capacity for trapping noxious gases.
Carbon filters come in many forms: impregnated foam material, powder and cloth, and solid carbon. These filters are the most absorbent filters available. These “active” carbons are charcoal that has been treated with oxygen to open pores between carbon atoms. These pores chemically react to contaminants as they pass into and through the filter in order to purify the air. When a mineral absorbs something, it does so through a chemical reaction and these filters are no different. Once all of the pores are filled, however, the activated charcoal filters stop working and must be replaced. Some prime examples of a carbon/charcoal filters are gas masks and air conditioning units filters.

Ok, I'm still missing the real scare here. Capturing pollutants/emissions from the process is a good, and the right thing to do, but I don't think it is a massive heath scare compared to other things we tackle on a day to day basis like using cleaning solvents or even worse having a pint? For my own benefit how are you supposed to handle a contaminated active carbon filter? I presume this is not a catalyst, but literally a filter that has an definite capacity? Again, containing and controlling pollutants is a good thing, but miss selling a pollutant control system as a critical piece of health and safety equipment based on over inflated (If I've miss read figures I'm happy to be corrected!) risks is bad!

I'm likely to need to do a risk assessment in the near future for this so a better understanding of the risk would really help me. Here's my take on the presented information and a quick google search on Styrene:

Four hour LC50 (concentration required for half of the test population to spring the mortal coil) for rats is 2700mgm^-3 which is listed as 634ppm. Irritation to the upper respiratory tract for mice occurred at 156ppm for 3 minutes (664mgm^-3) and behavioural changes from exposures of 413ppm (1757mgm^-3) for 4 hours. Reference 1

The 8 hour workplace exposure limits vary from 100ppm in the UK (be it with a obligation to reduce as far as possible) to 10ppm for new installations in Sweden. I would suggest a few hours at the UK government limit would have you feeling rough based on the respiratory tract irritation in mice. Reference 2

For the rest of this discussion we'll take 10ppm as a sensible limit which from the first reference equates to approximately 42.6mgm^-3. If our predicted (or indeed measured) values exceeded this then this system could be considered a critical piece of health and safety equipment.

The presented bar chart shows (assuming I've picked the right section - colour bar chart is a poor way of presenting information; unintentional discrimination against the colour blind) the emission from the machines to be between 30 - 110µg/min. Micrograms, so 1.8 - 6.6mg/hr to be consistent with the quoted references.

Let's assume the printers up in a sealed 1m³ box would give us an idea of how long they take to exceed the limits (with no idea on what the processing rates & conditions are for the presented information).

Lowest emission case:
42.6 / 1.8 = 23hrs40min.

Worst emissions case:
42.6 / 6.6 = 6hrs27min.

Now, take into account that this is assuming a completely sealed enclosure this and up until the times mentioned above are exceeded the concentration does not exceed the minimum European 8 hour workplace limit then stating "ABS emits large amounts of Styrene" is potentially misleading.

Now we can confuse things a little more by placing our printer into a small office and assuming a 3 air changes per hour. Reference 3 My office would do for a case study here: 2.6mx3.8mx2.5m. For the sake of my sanity we'll assume instant dispersal of the styrene into the room. Reasonably fair assuming a small room, good air circulation and the description of Styrene being 'Volatile'.

t (time elapsed in hours)
A (air changes per hour for the room) = 3
M_rate (rate of styrene emission in mg/hr) = 6.6mg/hr
M_total (Total emitted styrene, mg) = M_rate * t
M_room (Total styrene in room, mg)
V_r (Volume of room, m³) = 2.6 * 3.8 * 2.5 = 24.7m³
V_exhaust (Total amount of air that has moved through the room and is now outside, m³) = V_r * A * t
M_room = M_total * (V_r / (V_exhaust + V_r))
M_room = (M_rate * t) * (V_r / ((V_r * A * t)) + V_r)
M_room = (M_rate * t * V_r) / ((V_r * A * t)) + V_r)
M_room = (M_rate * t * V_r) / (V_r * (( A * t) + 1 ))
M_room = M_rate * t * (1 / ( At + 1 ) ) # V_r cancels out on the RHS.
M_room = (M_rate * t ) / ( At + 1 )

So with some big assumptions it roughly works out to a steady state of contamination level in the room being one over the number of air changes multipled by the mass contamination rate. The actual contamination level would be M_room / V_r

6.6 * 1/3 = 2.2mg

This in my office would be 2.2mg / 24.7m³ = 0.089mgm^-3

According to the first reference the times mgm^-3 values by around 0.235 to convert to ppm.

0.089 * 0.235 = 0.021ppm

There would appear to be quite a significant safety margin between the levels emitted and a risk to health?

I have no argument against handling the emissions, but accidentally eating apple pips would appear more dangerous at the moment! There are notes to this though, as I mentioned before. As there is a point source of of emission and the emitted gasses/particulates disperse then there will be areas of the room with higher contamination levels, such as in the immediate vicinity of the machine. It is also worth noting that people tend to be very sensitive to some chemicals and it is likely that you will choose to do something about the fumes long before it becomes a critical safety concern.

Edited 2 time(s). Last edit at 09/04/2017 07:24AM by WesBrooks.

That's very interesting WesBrooks, and I am quite confident these things are not an imminent danger to health.

Like a lot of "safety" it's the perception of safety that seems to matter. As such we smell fumes and worry about it. Reasonable ventilation/filtration can deal with this perception that there are toxins present, even if these toxins are not going to harm us in the concentrations we are exposed to.

As such a reasonably cheap solution makes sense, I bought a room filter system secondhand for £30, filters £10 and a time switch to run it for 10 hours at a time when I start a print £10. The room air smells of ABS when I'm printing it but a few hours after the print finishes it does not. Whether I have spent money on something I don't need as the risk is negligible or have I just bought £50 worth of piece of mind?

What would be very interesting would be if the work above could incorporate som device for measuring the presence and concentration of these pollutants, before and after implementing a solution, though I am sure this equipment is specialised and very expensive.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

No issues with what you say at all there. I'm only advising caution on how things are presented as we don't want to make things look an order of magnitude or more dangerous than they actually are. We are a group of knowledgeable individuals and have the experience to interpret the information we receive here. Outside of this forum, and specifically in business environments information and reports tend to get dumbed down a number of times before it reaches policy makers, and if the information starts with comments along the lines of all plastics emit dangerous fumes when processed in Material Extrusion Additive Manufcaturing systems and ABS emits large quantities of styrene then this isn't going to bode well for new users adopting the technology. If my presented model is fair then it clearly doesn't emit large quantities of Styrene, it merely creates enough of it to be an annoying smell - 0.00021% of the UK governments 8 hour exposure limit.

I can't see the earlier shared link as the site has been blocked by our firewall. Ideally we should be requesting that our filament providers include details of emitted gasses per unit mass of filament processed. This would be the sort of information I'd expect to see in a material safety data sheet. For us to tackle this at point of use is too expensive for most hobby users to consider, and since we are being sold this stuff for a specific purpose, not really our place to need to do it anyway.

The bar chart seems to allude to test that are in the right direction. I'd like to see the rest of that report, particularly to see the processing conditions at the hot end, and total material throughput.

I'm normally siding on the safer side of things in terms of PPE and chemical exposure, but cases like this can be misrepresented and add ammo to the people who whinge about H&S, nanny state, etc when really all that is happened is someone missed a reasonable risk assessment step. Yes, there are nasty chemicals being emitted, so don't stick you head in the machine while processing. There is a chance that one of the other emitted chemicals are far more hazardous than styrene, but on the strength of the presented evidence (and doing the leg work such as I did for styrene for the other chemicals) this is a project aimed at protecting damage to the environment by uncontrolled release of process exhaust rather than a H&S aid. The environmental concern also only being addressed if a community collectively accepts the measures rather than looking at the low level of emitted fumes from their own single system and saying it doesn't matter. A thousand 'it doesn't matters' add up to something that may well matter.

All that said I would suggest somewhere between 1/20th to 1/10th of the total machine build cost would be a completely reasonable amount to spend on these sort of environmental add-ons, so long as they don't add other risks. Cost in use has to be considered too. Is someone is running there system 8hrs a day 5 days a week in a commercial environment how much would it add to the cost of their product?

Edited 2 time(s). Last edit at 09/04/2017 09:18AM by WesBrooks.

It appears that not everyone agrees yet that printers emissions are toxic or level of their toxicity. Probably when making filtration product - OP will need to explain why their filtration system would help and is not just a 'snake oil'.

People are driven by experience and slow changes to their health or environment are harder to observe (think boiling frog) and even harder to attribute to a source (global warming, radiation, pollution). Dangers of some products are not understood or acknowledged until generation(s) later (lead in paint, radiation in beauty products, narcotics, cigarettes, BPA/phalates in baby products).

At this time we do know that plasticizers used in plastics are endocrine disruptors and plastics do emit toxins (of varying amount and toxicity).

Industrial guidelines show the need for ventilation and that styrene concentrations above 100ppm require use of respirator.

Of course industrial setting is quite different than 3d printing at home so it has to be adjusted accordingly. Knowing that 3d printing/filament is not regulated and because filament is formulated to flow well - not to be 'healthy' - I personally made a decision not to print ABS and print toys for children in PETG (in PLA for throwaway toys).

Quote
newbob
Industrial guidelines show the need for ventilation and that styrene concentrations above 100ppm require use of respirator.

The industrial guidelines linked are for industrial scale extrusion. 12kg/hr can be achieved from a small 25mm screw extruder. I'm in the process of upgrading an Ormerod 2 to a D-Bot. In the appendix it lists the maximum volumetric throughput of 12mm³/s. Taking the density of ABS as 1g/cm² we're extruding at a rate of 0.054kg/hr.

Consider the emissions from a bonfire. Now consider tea lights and other candles...

We just need the information to collectively make the right decisions for our own safety and for lower exposures the environment.

It does indeed get ugly where performance additives are directly increasing the toxicity of the process. This is very similar to the leaded petrol analougy and they should not have been able to add these without sharing the risks in use. If these evaluations are available I would like to see them.

Quote
WesBrooks
[...]

This in my office would be 2.2mg / 24.7m³ = 0.089mgm^-3

According to the first reference the times mgm^-3 values by around 0.235 to convert to ppm.

0.089 * 0.235 = 0.021ppm

There would appear to be quite a significant safety margin between the levels emitted and a risk to health?

I have no argument against handling the emissions, but accidentally eating apple pips would appear more dangerous at the moment! There are notes to this though, as I mentioned before. As there is a point source of of emission and the emitted gasses/particulates disperse then there will be areas of the room with higher contamination levels, such as in the immediate vicinity of the machine. It is also worth noting that people tend to be very sensitive to some chemicals and it is likely that you will choose to do something about the fumes long before it becomes a critical safety concern.

It's rather difficult/impossible to translate industrial guidelines to printing at home. For one, industrial norms are a compromise between business profitability and worker's safety - as you noted Swedish norms for new installations are 10x stricter than British.

Secondly, industrial norms assume that you do not consume food at the production area, maybe wearing special clothing and that you're adult and not pregnant.

Edited 1 time(s). Last edit at 09/04/2017 09:58AM by newbob.

A good parallel was in electronic cigarettes where a "scandal" erupted over a certain chemical present in them which was deadly and unsafe, but what prompted this was an industrial accident at a plant where 7 workers were exposed to massive doses of this chemical.

Real research on 3D printers used within the home is needed.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

There are many ugly truths when digging around legislation and protections. You could carry out an ISO 13849 style assessment for our printers and you may well find that our standard interlocks and safety measures fall well short of what would be expected on an industrial machine. I'd say more often than not you are better protected in the work environment than you are at home - if your employer isn't being negligent, wilfully or not.

Another parallel is the corrosive chemicals warnings on soft drinks concentrates.

I'll have a poke around to see if any of my contacts are aware of work in progress in the academic environment.

Edited 1 time(s). Last edit at 09/04/2017 10:10AM by WesBrooks.