Last week we looked into the questions: “What toxins are in paint?” and “Am I being poisoned by my paint?” Not unsurprisingly, artists and art supply companies are invested in answering these questions, and there are quite a bit of resources available to help identify toxins in paint (there are many) and help artists protect themselves while painting. This week we’ll ask: Is my paint poisoning the environment?
The short answer: yes, but in a limited way compared to other sources.
This question was more difficult to answer than the ones I covered last week. Although paint manufacturers are required to share information on how to use their products safely, they’re not required to share information on environmental impacts of their materials – and they don’t. Without talking to experts working in this field, there was a limit to what I could gather. However, common sense says that if your paint has toxic ingredients and you’re pouring it down the drain, that’s likely to have an environmental impact. I live in a rural area and have my own septic system and well. My family also grows most of the veggies we eat in our garden, which is in the same area as the septic system. So I have literal skin in the game when it comes to keeping toxins out of my wastewater stream. How concerned should I be about painty wash water?
As we learned last week, the heavy metals cadmium and cobalt are almost entirely bio-unavailable (not absorbable by your body or by plants) when used in artist paints. This is because the metals are chemically bound to other minerals as part of the pigment manufacturing process, making them insoluble if you ingest them – still bad if you breathe them though (more info here and here). They are also heavy, so pigment particles would likely sink in a septic tank and stay in the sludge. They can’t dissolve in water, which should help keep them out of the ground water – though I couldn’t find any info on this so that’s just speculation on my part. From my septic system, sludge is periodically pumped out, where it then joins the sewage from the sinks of my city-dwelling brethren at the sewage treatment plant. The treated sewage from our local plant is spread in a landfill, which is supposed to contain any toxic stuff inside (although there have been some notable failures). Worldwide, many agricultural soils are contaminated with cadmium, but this is mostly from contaminated fertilizer, fossil fuel burning, and cadmium released by mining, all larger sources of pollution than paint, by vast orders of magnitude.
Biocides, or ingredients added to paint to kill bacteria and fungi and keep paint from molding are also not good for the helpful bacteria in my septic system, however, the quantities are infinitesimally low so they shouldn’t really hurt anything unless I take up mural painting. Micro plastics from acrylic painting are perhaps the biggest concern here, although I’m likely making more micro plastics from washing synthetic clothing (again, unless I take up mural painting). I found this article on the topic informative, though it’s about latex housepaint. In case you’re wondering (as I was) the synthetic binder in QOR watercolor paint is not plastic, and is non-toxic and “environmentally friendly” according the manufacturer, Golden Paints.
When it comes to washing your brushes, there are some common sense methods to reduce the amount of paint going down the drain and into the environment. And even though the quantities we’re talking about are small, why not make that even smaller? This handout from Jackson’s Art is a good, succinct guide that I’ll probably be printing for my students going forward. To sum it up:
- Wash brushes in a jar rather than in the sink.
- Pour wash water into a bucket and let the water evaporate, then wipe the bucket out with a paper towel.
- Put painty paper towels in a clearly labeled container. When it’s full, dispose of it with hazardous waste according to the instructions for your area.
If you’re generating large quantities of wash water (maybe you are a mural painter!) this guide has instructions for precipitating paint from the water using hydrated lime and aluminium sulphate.
Pigment Production: The Other Environmental Impact
Before my paint even gets to me, there’s a whole litany of other opportunities for it to cause pollution:
- Mining and extracting the raw ingredients
- Manufacturing of the pigment
- Manufacturing of the paint
Most of the brands of paint available to me are manufactured in countries with fairly stringent environmental regulations and standards to protect the health of workers. The same cannot be said for pigment manufacturers. Pigment manufacturing is often a water and energy intensive process, and water pollution is a big concern (info here). Some pigments, such as some phthalo pigments, create PCBs (carcinogenic “forever chemicals” that don’t biodegrade) during their creation. Other pigments can cause air pollution, such as Ultramarine, which is made from clay baked with sulfur and generates sulfur gas.
Perhaps most concerning are the impacts of mining heavy metals. Cobalt is in high demand for the production of batteries and electronic equipment – only a very small percentage is used for pigments. However, 70% of the world’s cobalt is currently mined in The Democratic Republic of the Congo, under conditions that are deplorable for both the environment and for workers. Some have even referred to the mineral as “blood cobalt.” Cadmium mining, though a much smaller industry, can also lead to cadmium contamination of the surrounding area. About 3% of the cadmium mined is used to make pigments, and of that an even smaller percentage is used for artist’s paint. The majority of cadmium is used to make batteries, and surprisingly, jewelry (yikes?).
Since most of us are not in a position to directly influence how pigments are mined or manufactured, our ability to fix these problems is limited. However, there are some simple steps we can take as artists to do our part.
- Don’t waste paint. The less paint you buy, the less pollution your paint makes.
- It’s fine to use watercolor paint that’s dried on your palette. Set up your palette system so that you’ll know what’s in your mixtures and be able to use them for future projects.
- Old, hardened tubes of watercolor are perfectly useable. Use a craft knife to cut open the tube and scrape the dried paint into a small cup or palette well, mix it with water until it’s back to a normal consistency, then transfer it to pans.
- Purchase second-hand paint (from E-bay, watercolor swap groups, yard-sales, etc.) Sell or give away your unwanted paint.
- Don’t buy more paint than you need. Do you really need another new pigment to try?
- If your paint molds, don’t throw it out. You can easily kill the mold with rubbing alcohol and it will be fine to use.
- Demand information from paint manufacturers
As consumers, we can ask that paint manufacturers share information about the source of their pigments, and the environmental impacts of those sources, so we can make informed choices about what paint we buy. In addition, we can demand that manufacturers share the type of biocide used in their paints, and especially any paints that contain formaldehyde.
- Make informed choices
Now that I know more about the impacts of cobalt mining, I will think much harder about buying cobalt-based pigments in the future. Knowledge is power!
To that end, next week I’ll show off my experiments and research on replacements for cadmium and cobalt pigments in my watercolors. If you haven’t already, subscribe and get these articles delivered right to your inbox every Sunday!
Carrie Glessner 