It’s time to wash away water-washable 3D printer resins.
Resin 3D printing has exploded in the past few years, and there are several reasons for this. The prime factor has been the increasing availability of low-cost resin 3D printers that have truly amazing performance. It’s now possible to print incredibly detailed objects with near-perfect surfaces.
That, combined with the increasing number of fascinating 3D models available for purchase online, has brought countless thousands of people into the 3D print world.
There’s one catch: resins are toxic.
Exposure to 3D Printer Resin
A 3D printer operator can be exposed to the resin in several ways:
- While pouring resin into the machine
- When extracting completed prints from the machine
- While removing support structures
- While washing wet resin from the print
- When inserting the print into the curing station
- When removing resin from the machine
- When cleaning up inevitable resin spills
- Breathing resin fumes while working near the machine
While an exposure does not immediately result in a reaction, it turns out that your body will build up a resistance over multiple exposures. After some amount of exposure, you’ll suddenly have a reaction, perhaps quite serious. There are many stories of people who are now unable to be in the same room as 3D printer resin due to this effect.
It’s quite insidious: nothing seems to happen until it’s too late. Then you’re susceptible for the rest of your life.
Safety Precautions with 3D Printer Resin
Because of this, it is critically important to first ventilate properly and secondly wear appropriate personal protective equipment (PPE) whenever you use resin.
Ventilation is best done by extracting the air near the machine and exhausting it outside. If that’s not possible, then a proper fume extraction unit should be used, which pulls air through a powerful filter to remove contaminants.
For PPE, it’s important to not have any skin contact with resin. That means wearing sleeves, nitrile gloves, etc. Eye protection with safety glasses is mandatory. Finally, an appropriate respirator should be used, especially if the ventilation is sketchy.
When working with resin, it’s critical to carefully plan your workflow. If you don’t, you’ll quickly find your machine coated with resin, where you’ve been opening the machine or pushing buttons with wet gloves. You want to minimize drips by keeping wet objects away from open surfaces. The safest procedure will vary depending on the workstation setup.
The problem is that I’m pretty sure that a huge proportion of resin 3D printer operators don’t actually follow procedures carefully, or even be aware they should be doing so. Some even don’t use PPE, which is quite astonishing, and there are even videos showing operators literally touching the resin.
Clearly people don’t understand or want to deal with the risks of toxic resin. 3D printer manufacturers tend to downplay the risks or simply don’t mention them in their marketing materials.
What are Water Washable Resins?
Into this already difficult situation we have the introduction of “water washable” resins.
Normally fresh 3D prints are cleaned of wet resin by bathing them in a solution of 90%+ IPA. The resin dissolves in the IPA, leaving the print itself clean of resin, and ready for curing. Note that the resin is still toxic, it’s just in the IPA at that point. Dealing with dirty and toxic IPA is a question for another day.
The water washable resins are designed to be cleaned by either IPA or plain water. At first, this seems like a good thing: no IPA, just water! Everyone has water!
However, the resin is still toxic, and the exact same handling procedures must be done. The same PPE must be worn. The same dirty water will be made and eventually disposed of.
When using water washable resins, there is literally zero difference between IPA washable resins, except that the wash solution is water instead of IPA.
Oh, wait. Here’s a difference: water is priced somewhat lower than IPA. You don’t have to go and buy a jug of IPA. That’s a big saving of a few dollars, not much really, especially compared to the cost of resin.
So why would anyone bother with water-washable resins? It’s because the phrase “water-washable” implies some level of safety that exceeds normal IPA-washable resins.
Sure, water doesn’t emit odors like IPA does, but that is the only difference. I suppose you could say water is somewhat safer than IPA.
The Problem With Water Washable Resins
The problem is that operators seeing the phrase “water-washable” will mistakenly assume that it means the dirty water can be “washed away” down the regular water drains.
This is absolutely not the case: the water still contains the toxic resin, and dumping that dirty water introduces toxins into your environment.
It’s also quite possible that some may even assume that “water-washable” means it isn’t toxic at all. They may even avoid using PPE because of this assumption.
This could lead to a very dangerous situation where we have an increasing number of people developing resin reactions because they were fooled by the term “water-washable”. It’s quite possible we may see some significant lawsuits in the future as operators begin to realize what has happened.
What’s the answer here? I think it’s pretty clear: there should be no water-washable resins on the market. They provide almost no functional or cost benefits, yet dramatically increase the danger to 3D printer operators.
Let’s stop using water-washable resins today.
