Resin 3D printers, whether SLA or DLP, can produce extremely fine details in their prints, but there is one big problem with them: they produce a strong smell that most people find unpleasant. But are the fumes actually dangerous? It is no secret that the resin used in SLA and DLP 3D printers is toxic and harmful to people and the environment. It says so right on the labels of the canisters. Some resin bottles even recommend wearing a respirator or face mask before use.
However, the label does not convey all the information, at least not on the resin bottles that I have used. In a nutshell, resin 3D printers release VOCs, or volatile organic compounds, when they cure. VOCs have been linked to causing cancer, so clearly there is a serious danger in coming into contact with the resin and the fumes.
I am not sure what quantity of fumes you would have to inhale for it to cause problems, but I would definitely suggest that you err on the side of caution when working with these printers and avoid exposure as much as possible.
So how do you actually reduce the odor from resin 3D printers? The best way to reduce the smell of the fumes and the risk of harm from exposure is to simply vent the fumes to the outdoors.
Where to Put the Printer
The best way to avoid the fumes would be to place the printer in a place away from people and living areas, like in a garage or shed. However not everyone has a place or a room that they can dedicate solely to running a 3D printer, for instance people who live in apartments. Even if you do have a garage or outbuilding, if you live in a place where it gets cold or below freezing in the winter you probably should not leave your resin printer out in the cold.
Most 3D printing resins should be used at around room temperature. There is also the problem of the bad smell and fumes accumulating in whatever spare room you put it in. You could just open a window, but unless you have cross ventilation and a good breeze, the fumes can still accumulate in the room.
In my case I do have an unattached garage with electricity that I could potentially use to run the resin 3D printer, but I chose not to. For one thing it would be troublesome to have to go outside whenever I want to check on my print, and it’s a good idea to keep an eye on it while it’s printing.
If you notice that the print has failed, like if there was separation from the print bed, it can be helpful to notice it right away to avoid damage to the printer. That would be hard to do if it was in another room or building, so the best place is somewhere where you can see it. In my case I have it on a table right next to my office/study desk where I can constantly monitor it.
Ventilation Systems
As for ventilation, I went with a localized approach. Instead of ventilating the room, I have the printer vent into a cardboard box with a small table-mounted fan inside that blows the toxic fumes through an air duct and out a nearby window. This allows me to be able to still be able to sit around and work near the printer.
Many SLA and DLP resin printers will have a fan inside of them that blows their fumes out through a vent. In the case of my printer, the Anycubic Photon, these vents are at the back. I used the cardboard box that the printer was packaged in and cut a hole in one side to fit around the vents of the 3D printer. Then I just used tape to seal around the hole so that all the fumes go into the cardboard box.
The fan that I use is one that I already owned, and it has a clamp that allows it to be attached to the side of a table. I cut another hole underneath the box for the table fan to fit through. Then I cut the flaps of the box to create a pyramid shape that acts as a funnel that connects to the air duct. From there I simply taped the air duct to the box and ran the duct so that it blows out the nearest window.
If you use a similar approach make sure to check that your fan is creating enough air flow to move the air through to the end of the pipe. If you can feel the air flowing at the end of the duct then it should be fine.
I have seen other people use a similar method but with a bit more specialized parts which definitely look better, like a plastic adapter to fit over the printer vents, or an inline duct fan. All of these work very well, but if you don’t want to have to buy or 3D print special parts, you can just use things that you might already have, like a small fan.
If you don’t want to buy an air duct you can use any kind of tubing that you might have, or make your own out of paper or cardboard. It might not look the best, but it will get the job done, and you can always improve it later.
There are other ways to implement the same principle. Instead of having the ventilation system attach directly to the printer, you could fashion a type of hood that sucks the air up and blows it out the duct. Sort of like a stove hood, or the hoods used in laboratories to safely handle chemicals. These methods however would require a much stronger fan as they would be moving a larger quantity of air.
The approach that myself and others use of sucking the air straight out of the printer with a small fan has the advantage of extracting the fumes straight from the source, instead of letting them into a larger space and then moving it from there.
What Not to Do
Finally, there are some things that you probably should not do, for health and safety reasons. I have seen that some people simply block the vents off or disable the printer’s internal ventilation fan completely in order to stop it from blowing the fumes out. This, in my opinion, is dangerous for a few reasons.
First of all, the Anycubic Photon and other resin printers have an activated carbon filter that is extremely effective at trapping VOCs. By blocking the ventilation, you stop the fumes from passing through the filter.
Secondly, they just get trapped inside the printer and will probably be released slowly into the air as the printer door is not airtight, and then again when you open the door. The activated carbon filter looks like just a piece of black foam, but it is actually a very effective filter and should be allowed to do its job.
Conclusion
In summary, my recommendation is to extract the fumes from the resin 3D printer after they have passed through the built in air filter and vents, and then blow the fumes out a window. This will allow you to still be able to work near the printer or at least keep it in a place where you can keep an eye on it, and not have to worry about the smell or the health risks that it poses.
There are many ways to go about making the ventilation system, and at the end of the day you have to do what works for you, but I highly recommend that you do vent the fumes out of doors for the sake of your health.