I have not thought much about this till recently - there’s not a lot of science about breathing “harmless” plastic vapour and the long term effect on kids.
PLA and PETG are often touted as being harmless, or safe, but is it worth the risk? Other compounds have known nasty effects.
Two of my brothers-in-law developed fatal lung diseases from being around stuff that was thought to be harmless when they were young, perhaps statistically assisted by growing up in a household where one parent smoked.
My own view (now) after four years of printing in a “bedroom” beside my computer, is that even though the stuff is innocuous (perhaps) - I still get a slightly rough throat and a tingle in the sinuses after being locked with the printer for a few days.
I don’t want to risk any long term effects on visiting grandchildren, but I don’t have any means of reliably measuring particulates so just as in the filament drying thread, in true YouTube influencer style, I am acting on conclusions with no evidence.
I have a 90mm exhaust fan on my enclosure and have always intended to make a charcoal filter for it- but to be blunt, that means just one more consumable thing that I have to maintain.
You mention having no way to measure particulates so I thought this might be interesting to you. I have an environmental monitor that I made in my office that uses a Sensirion SEN55 for particulates in the range of PM1.0 to PM10 and a Sensirion SCD30 for CO2 and VOC measurement. It’s currently sitting on the desk directly beside the 3D printer, maybe ~150mm away?
The 2 spikes in particulate/CO2 are from when I was in the office working on things. Over the past 48 hours I’ve printed for maybe 14 hours total, roughly half a roll of PETG. There’s no appreciable change in particulates or VOC during that time.
That’s with my K1 max that’s moderately well enclosed and has a tiny little internal air filter setup.
Actually, I just remembered that I had to replace a roll halfway through and I left the top off for a few hours of one of the prints during that time, so no obvious increase in particle count there, either.
That’s super interesting - I have just cleaned the inside of my enclosure and it was covered with a very fine powder - and the perspex was noticeably dirty on the inside.
That is not to say that I disagree with actual measurements - that buildup represents hundreds of hours of print time so it’s probably trivial in a room at any given time.
I am very much trying to stay away from learning more about electronics, no matter how fascinated I am, nor how much I really want to build a monitor and do other stuff. I am already not a person with too few hobbies. (sigh).
I just open a window and have a fan against it blowing out when I’m printing asa. I got one of those bento box air filters, and I’ve decided it’s next to useless.
Given @jono’s notional evidence that the amounts are less than miniscule, I think I’ll go ahead and make the filters and feel warm and fuzzy anyway!
Fun Fact - I was looking for a product to use inside bee hives a couple of years ago. Prusa’s PLA and PETG were the only products that I could find with actual Endocrine Disrupter free certification on the MSDS’ - others may have - most others either ignored my question or replied as though I was some sort of nutter. (I am.)
You can really go nuts trying to chase this stuff. Not that we shouldn’t be careful. But let the evidence guide you, not your intuition.
I have a sensor in the middle of my house and I have used it to try and measure PLA particles. I can’t measure any. But you know what makes it go bananas? Bacon. Or roasting veggies. Or just preheating the (electric) oven. It can detect VOC, PM2.5, CO2.
It is true that when we put a new compound into our enviroment, we don’t know what the consequences will be. Stuff like asbestos takes decades to show the danger. Cancer sucks and if these new things can cause it, then we won’t know until it is far too late.
There are a lot of things we know cause cancer and we accept them. Red meat. Processed foods. Preserved meats. Camp fires. Plywood at Home Depot…
I haven’t seen any good evidence that PLA is any more dangerous than cooking. It seems like ABS and ASA are worse. But I’m not an expert. I keep my printer in the office and I won’t use resin or ABS. I would vent if I used ASA.
I’m not sure I’d read much into my measurements other than that a particulate sensor might not show you anything.
So, in my case I don’t see anything that would indicate particulate pollution which means that a conventional filter won’t help. An activated carbon filter may, but that’s starting to get into the realm of using a process that it’s monitorable to protect against something that may or may not be present. That all just seems a little bit too open-loop for me.
Personally, if I were concerned with it then I’d be trying to contain/exhaust to atmosphere rather than filtering it internally.
Measuring and filtering particulates, VOCs seems like a good idea as a preventative measure.
Anyone have opinions on more immediately benefits of monitoring and managing CO2?
Recently saw misc info/videos discussing how active CO2 (and monoxide) monitoring, and ensuring appropriate air circulation (or make up air) benefits cognition/productivity. Asking since, especially during colder months, many Maker spaces seem to be relegated to basement rooms/spaces, and sealed/damp areas with not so great air quality.
I want to make it clear here that I am not in any way trying to be ‘that’ kind of kook - curiosity more than anything is driving this.
There is no need to go down the EDC rabbit hole, unless you are looking for specific food safe solution (inside beehives or long term preservative storage of hot things) and if the manufacturer of the filament says it’s safe, well I’m an old fashioned girl who believes that.
CO2 is another curious subject - my brother in law says it’s no biggie, it’s only 0.05% of the atmosphere anyway so miniscule changes can have no effect on climate or anything else. I have asked him to calculate the volume percentage of a fart in a lift (elevator), but so far he hasn’t.
I like the idea of a bacon alarm - or perhaps a bacon mask for filament pongs!
Nothing that I’ve observed directly, but monitoring the CO2 in my office made me consider it a little more. The issue that I’ve noticed is that even with the office door open, the CO2 builds up towards 1000ppm pretty quickly, so I don’t think I can rely on just diffusion alone realistically. That was a surprise but it makes more sense upon further reflection. If you burn something and release something that smells bad, you don’t just sit there and wait for it to go away, you open a window and try to get some airflow.
Unfortunately, I put together that measurement right after I stopped working from home so I haven’t had the opportunity to actually try a couple of different things like comparing the open door to an open window or adding a small stirring fan etc. Our office has a reasonably active fresh-air intake so I’m less worried here but haven’t measured it directly.
As for the effects, that’s more of a ‘belt and braces’ approach, for me. I vaguely remember reading through several studies that were all in the single digit percentage range for cognitive effects. I think that was all measured by response time for specific tasks/calculations, not really an ability to do those calculations or correctness etc. Rationally, I don’t know that we actually spend that much time actively engaged in complex cognitive tasks so I don’t know how much that would map to a drop in actual real-world productivity, but it seems like it’s probably worth trying to reduce it just as a matter of course.
My bigger issue is that the sweet smell of printing PLA starts to make me a bit nauseous over long prints. So, I end up closing the office door and working elsewhere. I imagine that would be easily resolved with an exhaust fan venting outside. Maybe I’ll rig something up when I start printing my LR4 parts.
Unfortunately a charcoal filter will not do much as it’s essentially good for removing odors, but not particulates.
What you want to use here is a HEPA filter. The bigger, the better, because it is very restrictive air flow wise.
You also need a fan that is able to build static pressure, because you need air to be under pressure to push through the filter.
What worked well for me was to use a centrifugal blower fan. Avoid axial fans, they aren’t up to the task.
An easier way to do this is to simply purchase an air purifier. The Xiaomi Air purifiers are in my opinion the best ratio quality/power/price, and they have some interesting functions. For example you can program them to turn on or off at whatever speed of your choosing depending on actual particulates levels (it has an integrated detector), day, time, outside pollution levels, other external sensors and whatnot.
I’m not working for them, of course, but I spent a lot of time years ago building my own high power air purifier so I did a lot of research at the time.
I have a bunch of Honeywell HEPA filters. The HEPA filter itself can last for a few years, you just vacuum them every 1-3 months (depending on fan speed setting - I have two dogs, so I do mine pretty much monthly). The charcoal pre-filter is supposed to be replaced every month, but again, I usually just vacuum them monthly, and replace them about once a year. Amazing how much gets trapped in a month.
PVC was the worst! 
