Emissions of Ultrafine Particles and Volatile Organic Compou

[Windshadow]

This is a long and complex scientific examination of the situation and I have put the last paragraph below but the whole thing needs to be read for context
this image is posted as an example of the sort of thing in the whole document. the short version is that ABS and Nylon at high temps are bad and PLA is a lot better in a home environment
of course as I type this i am about 4 feet from my printer running a 4 hour ABS print at 228c
http://pubs.acs.org/doi/full/10.1021/acs.est.5b04983" onclick="window.open(this.href);return false;

Emissions of Ultrafine Particles and Volatile Organic Compounds from Commercially Available Desktop Three-Dimensional Printers with Multiple Filaments

Parham Azimi†, Dan Zhao†, Claire Pouzet†‡, Neil E. Crain§, and Brent Stephens*†
† Department of Civil, Architectural and Environmental Engineering, Illinois Institute of Technology, Chicago, Illinois 60616, United States
‡ Ecole des Ingénieurs de la Ville de Paris, 80 Rue Rebeval, 75019 Paris, France
§ Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
Environ. Sci. Technol., Article ASAP
DOI: 10.1021/acs.est.5b04983
Publication Date (Web): January 7, 2016
Copyright © 2016 American Chemical Society
ABSTRACT
Previous research has shown that desktop 3D printers can emit large numbers of ultrafine particles (UFPs, particles less than 100 nm) and some hazardous volatile organic compounds (VOCs) during printing, although very few filament and 3D printer combinations have been tested to date. Here we quantify emissions of UFPs and speciated VOCs from five commercially available filament extrusion desktop 3D printers utilizing up to nine different filaments by controlled experiments in a test chamber. Median estimates of time-varying UFP emission rates ranged from ∼108 to ∼1011 min–1 across all tested combinations, varying primarily by filament material and, to a lesser extent, bed temperature. The individual VOCs emitted in the largest quantities included caprolactam from nylon-based and imitation wood and brick filaments (ranging from ∼2 to ∼180 μg/min), styrene from acrylonitrile butadiene styrene (ABS) and high-impact polystyrene (HIPS) filaments (ranging from ∼10 to ∼110 μg/min), and lactide from polylactic acid (PLA) filaments (ranging from ∼4 to ∼5 μg/min). Results from a screening analysis of potential exposure to these products in a typical small office environment suggest caution should be used when operating many of the printer and filament combinations in poorly ventilated spaces or without the aid of combined gas and particle filtration systems.


[img]http://pubs.acs.org/appl/literatum/publ ... _0005.jpeg[/img]

3.5Implications for Human Exposure and Health Effects
Measurements of UFP and individual VOC emission rates presented here have important implications for human exposure and health effects. For example, styrene, which is classified as a possible human carcinogen by the International Agency for Research on Cancer (IARC classification group 2B),(23) was emitted in large amounts by all ABS filaments and the one HIPS filament. Caprolactam was also emitted in large amounts by four of the filaments: nylon, PCTPE, laybrick, and laywood. Although caprolactam is classified as probably not carcinogenic to humans,(24) the California Office of Environmental Health Hazard Assessment (OEHHA) maintains acute, 8-h, and chronic reference exposure levels (RELs) of only 50, 7, and 2.2 μg/m3, respectively.(25) We are not aware of any relevant information regarding the inhalation toxicity of lactide, the primary individual VOC emitted from PLA filaments.
To provide a basis for comparison to regulatory exposure limits and to help understand potential implications for human health, we used these estimates of UFP and individual VOC emission rates to predict steady-state concentrations that would likely result from constant printer operation in a typical small well-mixed office environment. This effort is not meant to serve as a detailed exposure model but rather as a screening analysis for potential health implications. We should also note that this analysis does not take into account proximity effects that could serve to substantially elevate exposures to both UFPs and VOCs in certain microenvironments compared to well-mixed conditions.
Let us assume that one desktop 3D printer operates continuously in a well-mixed 45 m3 furnished and conditioned office space (i.e., the same office space reported by Stephens et al.(7) Let us assume a worst-case scenario in which a single printer has the maximum median UFP and individual VOC emission rates from the findings herein, which include ∼1011 min–1 for UFPs, 183 μg/min for caprolactam, 113 μg/min for styrene, and 5 μg/min for lactide. Let us assume a typical office ventilation rate of 1 h–1,(26) no sorption losses for the three VOCs (likely a conservative estimate),(27, 28) and a typical UFP deposition loss rate constant of 1.3 h–1.(29) Under these conditions, steady-state indoor concentrations of each of these constituents would be elevated to ∼58 000 cm–3 for UFPs, ∼244 μg/m3 for caprolactam, ∼150 μg/m3 for styrene, and ∼6 μg/m3 for lactide.
The predicted caprolactam concentration (244 μg/m3) would exceed all three RELs identified by the California OEHHA,(25) which suggests that although there is considerable uncertainty in this estimate, exposure to caprolactam from desktop 3D printing in a typical office environment with nylon and nylon-based filaments could lead to adverse health outcomes, particularly for susceptible individuals. Acute exposure to high concentrations of caprolactam is known to be “irritating to the eyes and the respiratory tract” and “may cause effects on the central nervous system”, according to the Centers for Disease Control and Prevention (CDC).(30)
The predicted styrene concentration in this configuration (150 μg/m3) would be approximately 20 times higher than the highest styrene concentration measured in commercial buildings in the U.S. EPA BASE study(31) and more than 20 times higher than the average concentration in U.S. residences.(32) There are also reports that suggest exposure to styrene at these concentrations could be problematic for human health. For example, high indoor styrene concentrations have been estimated to yield relatively high lifetime cancer risks in previous studies that assumed typical potency factors,(33) and even moderate styrene concentrations (i.e., greater than only 2 μg/m3) have been associated with elevated risk of pulmonary infections in infants.(34)
Although we are not aware of any regulatory limits for indoor UFP concentrations, an increase in UFP concentrations to ∼58 000 cm–3 would be approximately 10 times higher than what we typically observe in indoor air in our office and laboratory environments and what has been reported as a typical 8-h average indoor concentration in schools.(35) However, it would only be moderately higher than typical time-averaged concentrations in homes(36) but lower than what is often observed in other microenvironments.(37)
Given these findings, we are prompted to make the following recommendations. First, additional measurements should be conducted to more accurately quantify personal exposures to both UFPs and speciated VOCs that account for proximity effects presented by typical 3D printer use patterns. Second, manufacturers should work toward designing low-emitting filament materials and/or printing technologies. Third, in the absence of new low-emitting filaments, manufacturers should work to evaluate the effectiveness of sealed enclosures on both UFP and VOC emissions or to introduce combined gas and particle filtration systems. Until then, we continue to suggest that caution should be used when operating many printer and filament combinations in enclosed or poorly ventilated spaces or without the aid of gas and particle filtration systems. This is particularly true for both styrene- and nylon-based filaments, based on data from the relatively large sample of printers and filament combinations evaluated here.

[Jimustanguitar]

This has come up a lot lately. Here's a Hackaday article that I stumbled upon over lunch.

http://hackaday.com/2016/02/01/3d-print ... w-science/" onclick="window.open(this.href);return false;

I'm curious if an enclosure with a simple carbon air filter as a vent would capture the majority of the fumes and particulate.

[Generic Default]

I think we should be looking at health outcomes for people who work[ed] in injection molding factories or extrusion factories around these types of plastics. If it turns out that everyone who worked near a big injection molding machine making ABS electronic enclosures all day got cancer, we should be worried. Same for nylon.

It sucks that they left out acetal as a printing material. From what I've heard, that outgasses formaldehyde and is by far the most dangerous plastic to breathe in. Looks like the polycarbonate is safe though.


Also, I'm a little bit skeptical about patents when it comes to this. I bet some company got a patent on an air filter integrated into a 3d printer while hoping that air filters would be required by law thus guaranteeing them a huge monopolized source of revenue without any work. This scenario seems typical in the US. For those of you reading this post a few years in the future from 2016 when all this comes up, keep in mind I'm a prophet.

[Windshadow]

I put it up for discussion not because I thought highly of it.

One thing I didn't see in the paper was how 'dangerous' 3D printing was versus other sorts of 'ultra fine' particles. Say from wood fires, or diesel exhausts, or the out gassing of paints, or heavily polluted air in LA, for example. Nor did I see control levels of background ultrafine particles in their experiments, nor the effect of stirring up the air by people passing by. Nor was there any description of what caution should be used. No, it's not a what I would judge the best look at this and of course its written in that special version of english only found in published papers from universities and the like.

Also there are lots of areas in the home that produce all sorts of things I expect. and in my home with my machine shop in the basement I expect that there are far worse.... I have vintage Tap Magic the sort with lots of 1.1.1.trychlor that I use for the tough jobs and other sorts of chemicals i use in firearm restoration with things like benzene but I am careful to use those out side with lots of ventilation.
in the machine shop I did switch to the veg based Trico micro drop systems from the old fashioned Venturi action mist type fog machines about 20 years ago cast Iron I cut dry of course. add in all the stuff used for old fashioned "hartfordprocess" hot blueing and fire bluing and slow rust browning that I do out in the barn and I bet I do lots of stuff that would get me in trouble if I tried to use them in a Biz in California

[Windshadow]

This has come up a lot lately. Here's a Hackaday article that I stumbled upon over lunch.

http://hackaday.com/2016/02/01/3d-print ... w-science/" onclick="window.open(this.href);return false;

I'm curious if an enclosure with a simple carbon air filter as a vent would capture the majority of the fumes and particulate.

A good summary of the paper Jim, I made me reflect on how tough cleaning the inside of the glass of a new car after a few months of parked in the summer sun heating and cooling cycles... the nice new car smell is all over the glass and getting it off can be a pain.... though it was easier with my last new car in 2004 than it was on the one before that in 1989 so perhaps they are improving things there too.

[3D-Print]

I have never regretted ventilating my enclosure. I only smell the plastic when I open up the enclosure right after a print finishes. Here is a link to what I did to vent the enclosure outside (http://forum.seemecnc.com/viewtopic.php?f=42&t=8458" onclick="window.open(this.href);return false;)

[Windshadow]

I have never regretted ventilating my enclosure. I only smell the plastic when I open up the enclosure right after a print finishes. Here is a link to what I did to vent the enclosure outside (http://forum.seemecnc.com/viewtopic.php?f=42&t=8458" onclick="window.open(this.href);return false;)

I like your enclosure design and the temperature control readout ... does it control the 3 halogen lamps to maintain the temperature ? did you do a build thread on your design?

io was thinking of an enclosure along the same lines but then exhausting through one of those hepa plus activated charcoal filters that are used in nonvented range hoods that way i would not need to vent to the outside and have to drill through 3 layers of old brick...
though i guess i could move the printer to room that sharers a wall with the bathroom and tie into the plumbing vent stack

[nebbian]

This is something that I'm starting to get more and more concerned about. Thanks for posting your ideas and experiences.

I just bought some fans to make some of these:
http://www.thingiverse.com/thing:125264" onclick="window.open(this.href);return false;

Apparently they work well.

[Windshadow]

Thanks for that link Nebbian, i had never thought of using gas mask filters they would i am sure do the job.
I wonder how many hours of use they would be good for and if they are the sort that can be baked out and reactivated..
the author has put a lot of work and clever engineering into his design there is no doubt about that.
When you build it please keep us all up to date on your progress

[3D-Print]

Here is my build thread and about where I build my enclosure and added the halogens (http://forum.seemecnc.com/viewtopic.php ... =50#p63313" onclick="window.open(this.href);return false;). The enclosure is jfettig's design.

The temperature readout is simply a probe at the bed level and is just a read out I have not set up anything to adjust the intensity of the halogens. Wouldn't be hard to automate but honestly it is quite easy for me to set and hold a temp steady with halogen dimmer.

Addendum: here is a link to the jfettig's enclosure (http://forum.seemecnc.com/viewtopic.php?f=42&t=7149" onclick="window.open(this.href);return false;)

[Zent]

This is actually pretty scary, I work at a flexible PVC injection molding company. But I work in R&D, a building next door to the factory. Ever since I started here, in the factory there is black soot every where. I always thought it was dust but as I worked my way around the factory, this black soot is in every single corner of the 20000 sq/ft factory. Got me paranoid how many days I lose walking in and out of that place multiple times a day.

[rehabmax]

I set my Rostock Max V2 up in my basement. I have been printing with it for 4 months now. This a relatively closed in space. I have a ceiling fan in the area but this would just blow the particulates around more I suspect. I print mostly in PLA and there are fumes form the melting filament.

i would rather not find out in 5 years that i have some type of incurable lung disease. I figure I get more crap in my lungs if I get behind some diesel truck than with my 3D printer.

Any suggestions for making this a safer operation? Is it really necessary? I built plenty of plastic models with modeling glue for years.

What type of enclosure would be feasible to make with a filter to trap the small particulates?

Is there really a risk that warrants going to the trouble of making an enclosure and filtration on the printer? Almost every printer is an open design. The ones with doors on them I thought were mostly for safety reasons from kids curious hands than for particulate control.

Thanks for any suggestions.

[IMBoring25]

The comment about UFP concentrations being 10 times higher than office and laboratory environments but only marginally higher than the time-averaged concentration in homes is very interesting. Almost sounds like we should all live at the office.

[Windshadow]

I found this place on a google search
http://3dprintclean.com/scrubber-filtration.htm" onclick="window.open(this.href);return false;
for his $200 device and he sells the refill filters for $30 each or $260 for 10. but if you go to the order page you can see he is selling a total solution of filter and sealed enclosure

it looks to me his is going after the public printer places like Library and school and maker space usage... which makes sense from a potential liability standpoint

he has these interesting test plots on his site for ABS and from these it seems to work well on ABS
[img]http://cdn.snappages.com/1tanat/assets/ ... 997609.png[/img]
and PLA
[img]http://cdn.snappages.com/1tanat/assets/ ... 997609.png[/img]