Resin in its uncured form is toxic. There’s a reason you have to wear gloves when you handle it.
That means that unlike with FDM printers, resin 3D printing necessitates responsible waste disposal.
While I’ve put together a guide below, I will add an obligatory reminder that you should review the MSDS (Manufacturer Safety Data Sheets) of any chemical you’re unsure how to handle or dispose of.
Here’s an example MSDS for Elegoo photopolymer resin (their standard resin). Under Section 13, you’ll find this excerpt:
Section 13. Disposal Considerations
Waste Treatment Methods Recommendation: Cure material before disposal. Dispose in accordance with all federal, state and local regulations. Consult state and local hazardous waste regulations to ensure complete and accurate classification of waste. US EPA guidelines for the classification of hazardous waste are found in 40 CFR part 261.3.
Uncleaned packaging Recommendation: Rinse with alcohol. Contain and dispose of rinse material according to all federal, state and local regulations.
Recommended cleansing agent: alcohol
3 ways to dispose of resin:
Option 1: Call your local waste centre
Your nearest tip, recycling centre or other waste collection centre may be able to accept cured or uncured resin. Give them a call to discuss the particulars and they should be able to give you a very easy stream to drop-off, pay a small fee and go. The fee for mine is typically $20. When I go, I try to drop off other unwanted items at the same time – like old furniture or other items building up in the garage. This makes the trip more valuable. This is my preferred method for disposing of resin. It’s the safest and lowest effort to outcome ratio.
Option 2: Find Chemical CleanOut Events:
If available, dispose of uncured resin through a designated chemical waste disposal program. In Australia, New South Wales has a free government service program and Victoria has one here. For other areas, search your local area and the phrase “Cleanout Events”.
How it works:
1. Find a drop-off location and date
Find drop-off locations and dates by visiting the Household Chemical CleanOut website or calling the NSW environment line on 131 555.
2. Drive your items to the drop-off point
Transport your items in your vehicle’s boot. Ensure containers are tightly sealed. Label the item as resin. You will then stay in your vehicle at the drop-off site – an attendant will come to you. People walking or riding can access a separate drop-off area.
Personally, I find the drive to the local tip to be less work and coordination.
Option 3: Cure your resin and dispose of it at home:
Can you throw resin into the red bin in Australia? Yes – but only if it’s been cured.
Once completely cured, resin is safe to dispose of alongside general waste. You can throw away cured prints and empty or leftover resin containers in regular trash. Here’s how I have gone about it in the past.
- Store resin scraps: Keep a plastic bin bag in your printing room to place any prints, supports, failures, empty resin bottles, unwanted tools that have come into contact with resin, and consumables such as FEP, gloves or paper towels. Where possible, wash items out with isopropyl alcohol before putting them in the bin bag.
- Store used alcohol: Keep a container for storing any used alcohol with resin in it.
When the resin bin bag fills up:
Take it somewhere sunny where people and pets won’t reach and cut the bag open, ensuring all parts of the resin get exposed to sunlight for at least 48+ hours (you can also use a UV light for faster curing times). Ensure direct sunlight or UV light can reach everything, including the inside of any empty resin containers. Everything can then be thrown away in the regular trash (red bin).
When the container with used isopropyl alcohol fills up:
Alcohol will evaporate in the sun. You’ve probably noticed how quickly it evaporates if you’ve ever not sealed your isopropyl container up airtight. This means you can leave your alcohol exposed to the sun as per the method above and over time it will evaporate on its own. This will also cure any resin leftover in the alcohol, allowing you to dispose of whatever is left in the regular trash (red bin).
Note: Your resin bottle should contain specific instructions for safe disposal methods.
UV-Light for Curing
A good alternative for if you don’t have a spot outside in the sun. This can be used indoors such as in a garage – just don’t expose yourself to it directly.
UV-Light Curing Station
Much quicker than sunlight, but only capable of smaller batches.
Nitrile Gloves
Regardless of resin type, always make sure you’re using nitrile gloves when working with it. Do not touch resin directly.
How not to dispose of resin:
- Don’t pour resin down the drain. This can do everything from contaminating your water, to damaging your pipes, to putting maintenance workers and the environment at risk.
- Don’t put resin directly into your bins or waste collection. Unless it has been cured – wash it in alcohol and then expose it to UV light.
Important notes about different types of resins:
Working with water washable resins
Any resin-touched water should not be poured down the drain without curing.
This includes water washable resin – so don’t pour water used to wash this type of resin down the sink. Expose the water used to rinse water washable resin to sunlight or UV light to solidify the resin, then strain the solids and dispose of them with regular trash. You can then pour out the clean water.
Working with plant-based resins
Contrary to how they sound, plant-based or eco-friendly resins are not at all biodegradable. They can’t go in the compost, cured or not, and they aren’t any safer for the environment than regular resin. The benefit of the plant based resin ranges (which I primarily use) is that they are generally safer for people and animals due to lower levels of volatile organic compounds (VOC) and fewer irritants. They’re safer for you – not the planet. They are still resin and require equally as strict disposal measures. That said, I still highly recommend you give plant-based resin a try. I haven’t found any difference compared to standard resin and it’s less toxic, a frequent concern for if any pets, kids or other people come into contact with your hobby by accident. It also has a much lower odour than petroleum-based resin.
Elegoo Plant-based Tough Resin
Make sure to check their website to determine the best print settings for your resin printer.
What kind of resin needs to be disposed of safely?
As a general rule, if you’re unsure, cure it or take it to a waste centre. Below is a list of items which definitely cannot be thrown directly in the bin without curing:
- Liquid resin
- Empty resin bottles
- Printed resin supports
- Uncured resin models or failures (uncured meaning they have not been exposed to UV light)
- Used printing consumables like gloves and paper towels
- Used cleaning supplies
What is safe to throw away the regular way?
You can throw resin directly into regular trash (in Australia, that means the red bin or General Waste Bin) only if the following is true:
- The resin has been solidified (that is, printed)
- The resin has been cured (that is, washed in alcohol and doused in UV light)
To summarise – resin is toxic. In order to dispose of it safely, you’ll need to either expose it to UV light (that is “cure it”) or take it to a local tip. The same goes for anything that has come into contact with resin – be it alcohol, water, cleaning supplies, paper towels, filters, or gloves.
