<p><strong>You are probably pretty safe printing PLA</strong></p>

<ol>
<li><p>Regarding emissions, the following recent report, <a href="https://pubs.acs.org/doi/pdfplus/10.1021/acs.est.5b04983" rel="noreferrer">Emissions of Ultrafine Particles and Volatile Organic Compounds
from Commercially Available Desktop Three-Dimensional Printers
with Multiple Filaments</a>, indicates that PLA is a pretty low emitter (1/20th of nylon) and most of what it out-gasses is Lactide which is low on the harm scale.  That said, everybody's nose sees things a bit different and people tolerate smells differently. Note also that we used to think lots of things (like asbestos) were harmless that we know differently now.  Note also in the figure below from the <a href="https://pubs.acs.org/doi/pdfplus/10.1021/acs.est.5b04983" rel="noreferrer">report</a> that all PLAs are not created equal.  Dremel PLA produce way more nasty stuff than FlashForge PLA did.  I am also sure additives, colorant, and fillers can change this a lot as PLA filaments aren't not all PLA.</p>

<p><a href="https://i.sstatic.net/oFK7Y.jpg" rel="noreferrer" title="Estimates of emission rates for the top three highest-concentration VOCs"><img src="https://i.sstatic.net/oFK7Y.jpg" alt="Estimates of emission rates for the top three highest-concentration VOCs" title="Estimates of emission rates for the top three highest-concentration VOCs"></a></p></li>
<li><p>Regarding the fire safety issue.  Note that there is a BIG difference between a kit and a "product".  Since you are the manufacturer of the printer for a "kit", the packager of the "kit" is not responsible for the fire or electrical certifications of the final product.  This does open the door to some risks.  The biggest risks are electrical safety; but, fire safety can be an issue as well.  I would say that the risk is likely higher to you personally when the printer is NOT in your bedroom as if it catches fire when you are sleeping, you will likely catch the fire faster if it is in your bedroom.</p></li>
<li><p>From a practical standpoint, I have heard several people complain that they can't sleep when the printer is printing when the printer is in a separate room.</p></li>
</ol>

CC BY-SA 4.0
2018-08-28T03:11:50.483Z
2018-09-09T09:21:17.923Z
2018-09-09T09:21:17.923Z
markshancock
<p>I have been printing daily for 2 months with PLA and have noticed respiratory problems!  I feel like slight pneumonia symptoms!
I also have very sensitive lungs that react to things that would not bother normal people.</p>

CC BY-SA 4.0
2019-03-27T14:01:02.003Z
2019-03-27T14:01:02.003Z
Jeff McCray
<p>Having asthma, I'm very sensitive to air quality and when i first started 3D printing i quickly noticed a sore throat, feeling out of breath, headaches and well the smell.</p>

<p>One thing many beginners overlook is material oozing out of the extruder in places other than the nozzle itself. This causes a dirty extruder head which 'burns' that material and thus creating a ton of air pollution and a nasty smell.
As a fix, i took my extruder head apart and reassembled it with PTFE tape on all the threads. The oozing and burned smell of material is now completely gone, my initial health issues have also gone away.</p>

<p>This does not take away the fact that ultrafine particles are still being generated, but you will not notice this problem in an acute way. If you print daily use a fume extractor, your lungs cannot clean out this size of particles. The health effects will be similar as living near a busy street or highway.</p>

<p>One last thing few people mention: cleaning up parts. When you file or sand down parts this creates a lot of very fine dust, and since plastics are electrostatic this becomes very hard to clean up. I now use an extraction fan whenever I'm cleaning up a printed part.</p>

CC BY-SA 4.0
2019-04-04T06:09:24.770Z
2019-04-04T06:09:24.770Z
Jooch
<p>Standard manufacturing practices contraindicate leaving a manufacturing device unmonitored while it's on. That being said, your workshop should be well ventilated anyways since you're probably using acetone, isopropyl alcohol, and other substances that you shouldn't inhale.</p>

<p>If you can not move to a well ventilated workshop, consider installing a fume hood or at least a range hood in your current workshop</p>

CC BY-SA 4.0
2018-08-28T21:05:18.313Z
There are 3D printers certified for "lights out" manufacturing usage.  The Ender 3 isn't one of them (nor are any of the other hobby-level printers).
Mark
CC BY-SA 4.0
2018-08-29T13:07:11.213Z
thanks @Mark, this is important for non-hobbyists in manufacturing to know. Can you share any of them here? What does the certification process involve?
Mohammad Athar
CC BY-SA 4.0
2018-08-29T19:51:40.607Z
I don't remember the names, I just saw it mentioned in passing in a discussion of fire safety on https://www.reddit.com/r/3Dprinting/
Mark
CC BY-SA 4.0
2019-03-01T16:20:37.900Z
Most "lights off" 3D printer are industrial grade.
Trish
CC BY-SA 4.0
2018-08-27T13:33:47.067Z
2018-08-27T13:33:47.067Z
Mohammad Athar
<p>Fire is the most obvious risk - firmware can now detect some of the more obvious failure modes such as a detached thermistor, but loose or failing connections can still overheat. A smoke alarm is a fairly obvious (but not necessarily effective) protective measure.</p>

<p>The risk from particulates in particular is <em>probably</em> low, but marginal health risks like this are extremely hard to analyse, and will likely take many years to manifest. The closest analogue would be to look at commercial plastics workers since they are exposed to both heated plastic, and any potential dust generated.</p>

<p>You could also compare the risk to other 'hobby' activities such as soldering, painting, woodworking.</p>

CC BY-SA 4.0
2018-08-23T14:31:55.530Z
Very good points, @Sean Houlihane, but what's your risk assessment?
ifconfig
CC BY-SA 4.0
2018-08-23T14:33:43.133Z
Risk is your decision. Why would you care what risks I take personally?
Sean Houlihane
CC BY-SA 4.0
2018-08-23T16:09:01.263Z
"Most" but not all hot ends will not explode if their temp sensor breaks. Firmware usually detects issues such as disconnected thermistor. The only fires I have been aware of were the Flash Forges and electrical fires on the board it self from cheap / bad solder jobs. 

I agree that the risk is unknown. I would not say Low. The issue is with fine air particulates, which are known to be bad for your health. Pro labs that work with plastics and such will have industrial fume extractors. Which you can build your own with an inline fan and an enclosure.
MakerModder
CC BY-SA 4.0
2018-08-23T16:32:35.530Z
@StarWind0 You comment would probably be better as an answer, otherwise it may eventually be deleted.
Sean Houlihane
CC BY-SA 4.0
2018-08-23T16:58:23.073Z
@StarWind0 Also, some cheap printer firmware has the "Temperature runaway protection" disabled.
Trish
CC BY-SA 4.0
2018-08-28T05:28:47.657Z
Why would you rate a smoke alarm as "not necessarily effective"?
vwegert
CC BY-SA 4.0
2018-08-28T11:34:19.880Z
@vwegert "in smoldering fires ionization alarms respond an average of 15 to 50 minutes slower than photoelectric alarms", again, its a judgement call and I want to leave the reader to make their own assessments.
Sean Houlihane
CC BY-SA 4.0
2019-03-27T20:38:18.327Z
This entire answer is pure conjecture and I am not sure why it was marked as the correct answer.
Anthony Nichols
CC BY-SA 4.0
2018-08-23T10:42:36.403Z
2018-08-23T10:42:36.403Z
Sean Houlihane
<p>I have an Ender 3 which I primarily use for printing with PLA. I haven't branched out to other materials yet. :)</p>

<p>I've done <a href="https://3dprinthq.com/desktop-3d-printer-safety/" rel="noreferrer">some research into PLA fumes and airborne particulates</a> which seemed to mention that PLA is mostly safe, but ABS is rather dangerous to print without proper ventilation. However, I understand that there isn't much research on the topic and that there haven't been many studies.</p>

<p>I have been keeping my printer in my bedroom, far isolated from flammable materials, which I sometimes leave on to print while I'm asleep. Should I be concerned with my health safety with respect to airborne particulates emitted by printing with PLA?</p>

<p><strong>Other questions ask about ABS, but here, I'm asking specifically about PLA.</strong></p>

CC BY-SA 4.0
2018-08-23T06:32:36.127Z
Related [Enclosure, things to pay attention to?](https://3dprinting.stackexchange.com/questions/4220/enclosure-things-to-pay-attention-to) and [Is 3D printing safe for your health?](https://3dprinting.stackexchange.com/questions/2/is-3d-printing-safe-for-your-health)
Greenonline
CC BY-SA 4.0
2018-08-23T06:41:33.043Z
Good point, @Greenonline, but I'm asking more specifically about PLA. The Ender 3 isn't very well optimized for ABS, and I don't plan on trying to use it anytime soon. The only other filament kinds I'd be trying are PETG and TPU. Otherwise, I'd just use PLA with my printer.
ifconfig
CC BY-SA 4.0
2018-08-23T15:30:54.420Z
Possible duplicate of [Is 3D printing safe for your health?](https://3dprinting.stackexchange.com/questions/2/is-3d-printing-safe-for-your-health)
Carl Witthoft
CC BY-SA 4.0
2018-08-23T16:48:11.427Z
Even though PLA is plant based, and not full-on chemicals, living/sleeping in any environment with *fumes* (i.e. particulates) can't be good for you long term. Vaping with VG (vegetable glycerine) is *meant* to be (relatively) harmless but, as a chain-vaper, I can still feel negative effects to my respiratory and cardio-vascular systems. I would, IMHO, advise against it, without good filtering/ventilation.
Greenonline
CC BY-SA 4.0
2021-02-07T18:10:05.470Z
Wow how do you manage to sleep with the sound of the printer running?
Sixtyfive
<pla><safety><health>
Serious safety concerns with living in same room as PLA 3D Printer?
ifconfig
# Serious safety concerns with living in same room as PLA 3D Printer?

(Asked by: username_0 on 2018-08-23)

I have an Ender 3 which I primarily use for printing with PLA. I haven't branched out to other materials yet. :)

I've done [some research into PLA fumes and airborne particulates](https://3dprinthq.com/desktop-3d-printer-safety/) which seemed to mention that PLA is mostly safe, but ABS is rather dangerous to print without proper ventilation. However, I understand that there isn't much research on the topic and that there haven't been many studies.

I have been keeping my printer in my bedroom, far isolated from flammable materials, which I sometimes leave on to print while I'm asleep. Should I be concerned with my health safety with respect to airborne particulates emitted by printing with PLA?

**Other questions ask about ABS, but here, I'm asking specifically about PLA.**

**Tags:** pla, safety, health
> **Comments:**
> **username_1**: Related [Enclosure, things to pay attention to?](https://3dprinting.stackexchange.com/questions/4220/enclosure-things-to-pay-attention-to) and [Is 3D printing safe for your health?](https://3dprinting.stackexchange.com/questions/2/is-3d-printing-safe-for-your-health)  
> **username_0**: Good point, @Greenonline, but I'm asking more specifically about PLA. The Ender 3 isn't very well optimized for ABS, and I don't plan on trying to use it anytime soon. The only other filament kinds I'd be trying are PETG and TPU. Otherwise, I'd just use PLA with my printer.  
> **username_2**: Possible duplicate of [Is 3D printing safe for your health?](https://3dprinting.stackexchange.com/questions/2/is-3d-printing-safe-for-your-health)  
> **username_1**: Even though PLA is plant based, and not full-on chemicals, living/sleeping in any environment with *fumes* (i.e. particulates) can't be good for you long term. Vaping with VG (vegetable glycerine) is *meant* to be (relatively) harmless but, as a chain-vaper, I can still feel negative effects to my respiratory and cardio-vascular systems. I would, IMHO, advise against it, without good filtering/ventilation.  
> **username_3**: Wow how do you manage to sleep with the sound of the printer running?  

---

## 5 answers

### Answer by username_10 on 2018-08-23. Score: 14 | Accepted answer

Fire is the most obvious risk - firmware can now detect some of the more obvious failure modes such as a detached thermistor, but loose or failing connections can still overheat. A smoke alarm is a fairly obvious (but not necessarily effective) protective measure.

The risk from particulates in particular is *probably* low, but marginal health risks like this are extremely hard to analyse, and will likely take many years to manifest. The closest analogue would be to look at commercial plastics workers since they are exposed to both heated plastic, and any potential dust generated.

You could also compare the risk to other 'hobby' activities such as soldering, painting, woodworking.

> **Comments:**
> **username_0**: Very good points, @Sean Houlihane, but what's your risk assessment?  
> **username_10**: Risk is your decision. Why would you care what risks I take personally?  
> **username_11**: "Most" but not all hot ends will not explode if their temp sensor breaks. Firmware usually detects issues such as disconnected thermistor. The only fires I have been aware of were the Flash Forges and electrical fires on the board it self from cheap / bad solder jobs.   I agree that the risk is unknown. I would not say Low. The issue is with fine air particulates, which are known to be bad for your health. Pro labs that work with plastics and such will have industrial fume extractors. Which you can build your own with an inline fan and an enclosure.  
> **username_10**: @StarWind0 You comment would probably be better as an answer, otherwise it may eventually be deleted.  
> **username_9**: @StarWind0 Also, some cheap printer firmware has the "Temperature runaway protection" disabled.  
> **username_12**: Why would you rate a smoke alarm as "not necessarily effective"?  
> **username_10**: @vwegert "in smoldering fires ionization alarms respond an average of 15 to 50 minutes slower than photoelectric alarms", again, its a judgement call and I want to leave the reader to make their own assessments.  
> **username_13**: This entire answer is pure conjecture and I am not sure why it was marked as the correct answer.  

---

### Answer by username_4 on 2018-08-28. Score: 18

**You are probably pretty safe printing PLA**

1. Regarding emissions, the following recent report, [Emissions of Ultrafine Particles and Volatile Organic Compounds
   from Commercially Available Desktop Three-Dimensional Printers
   with Multiple Filaments](https://pubs.acs.org/doi/pdfplus/10.1021/acs.est.5b04983), indicates that PLA is a pretty low emitter (1/20th of nylon) and most of what it out-gasses is Lactide which is low on the harm scale. That said, everybody's nose sees things a bit different and people tolerate smells differently. Note also that we used to think lots of things (like asbestos) were harmless that we know differently now. Note also in the figure below from the [report](https://pubs.acs.org/doi/pdfplus/10.1021/acs.est.5b04983) that all PLAs are not created equal. Dremel PLA produce way more nasty stuff than FlashForge PLA did. I am also sure additives, colorant, and fillers can change this a lot as PLA filaments aren't not all PLA.

   [![Estimates of emission rates for the top three highest-concentration VOCs](https://i.sstatic.net/oFK7Y.jpg "Estimates of emission rates for the top three highest-concentration VOCs")](https://i.sstatic.net/oFK7Y.jpg "Estimates of emission rates for the top three highest-concentration VOCs")
2. Regarding the fire safety issue. Note that there is a BIG difference between a kit and a "product". Since you are the manufacturer of the printer for a "kit", the packager of the "kit" is not responsible for the fire or electrical certifications of the final product. This does open the door to some risks. The biggest risks are electrical safety; but, fire safety can be an issue as well. I would say that the risk is likely higher to you personally when the printer is NOT in your bedroom as if it catches fire when you are sleeping, you will likely catch the fire faster if it is in your bedroom.
3. From a practical standpoint, I have heard several people complain that they can't sleep when the printer is printing when the printer is in a separate room.


---

### Answer by username_5 on 2019-03-27. Score: 5

I have been printing daily for 2 months with PLA and have noticed respiratory problems! I feel like slight pneumonia symptoms!
I also have very sensitive lungs that react to things that would not bother normal people.


---

### Answer by username_6 on 2019-04-04. Score: 4

Having asthma, I'm very sensitive to air quality and when i first started 3D printing i quickly noticed a sore throat, feeling out of breath, headaches and well the smell.

One thing many beginners overlook is material oozing out of the extruder in places other than the nozzle itself. This causes a dirty extruder head which 'burns' that material and thus creating a ton of air pollution and a nasty smell.
As a fix, i took my extruder head apart and reassembled it with PTFE tape on all the threads. The oozing and burned smell of material is now completely gone, my initial health issues have also gone away.

This does not take away the fact that ultrafine particles are still being generated, but you will not notice this problem in an acute way. If you print daily use a fume extractor, your lungs cannot clean out this size of particles. The health effects will be similar as living near a busy street or highway.

One last thing few people mention: cleaning up parts. When you file or sand down parts this creates a lot of very fine dust, and since plastics are electrostatic this becomes very hard to clean up. I now use an extraction fan whenever I'm cleaning up a printed part.


---

### Answer by username_7 on 2018-08-27. Score: 0

Standard manufacturing practices contraindicate leaving a manufacturing device unmonitored while it's on. That being said, your workshop should be well ventilated anyways since you're probably using acetone, isopropyl alcohol, and other substances that you shouldn't inhale.

If you can not move to a well ventilated workshop, consider installing a fume hood or at least a range hood in your current workshop

> **Comments:**
> **username_8**: There are 3D printers certified for "lights out" manufacturing usage.  The Ender 3 isn't one of them (nor are any of the other hobby-level printers).  
> **username_7**: thanks @Mark, this is important for non-hobbyists in manufacturing to know. Can you share any of them here? What does the certification process involve?  
> **username_8**: I don't remember the names, I just saw it mentioned in passing in a discussion of fire safety on https://www.reddit.com/r/3Dprinting/  
> **username_9**: Most "lights off" 3D printer are industrial grade.  

---

