One of my students in Sea & Sky at Acadia National Park last week is a PhD researcher in the health sciences. I was thrilled to hear her disparage cobalt blue, not for its rather muddy color, but for the health risks associated with metal pigments.
Many traditional artist pigments contain toxic metals. These include cadmium (cadmium red, cadmium yellow), cobalt (cobalt blue, cobalt green), lead (lead white, flake white), and chromium (chromium oxide, viridian). In powdered form, heated as encaustics, or when sanded, they can be inhaled or ingested. Their health effects can be very serious, including organ damage, neurological problems and cancer risk. (As a three-time cancer survivor, I take this seriously.) The problem is most serious with loose pigments (as in pastels) or when heated in encaustics. But even when bound in oil or acrylic binders, small chips, dust or contaminated hands still pose hazards.
As real as these health hazards are, they pale in comparison to the risks to the people making these pigments. We’ve shipped our most egregious safety hazards to the developing world, where health and safety regulations are severely limited, and child labor isn’t unknown. Sadly, pigment manufacture is done almost entirely in those places. When you buy a tube of paint including heavy metal pigments, you’re contributing to that problem.
How do you know what pigments are in your paint?
All good manufacturers tell you what’s in their paints, either online or on the tube. The marketing name can be confusing, so I wrote this blog post to explain how to determine what’s in your paint.
Environmental toxicity
When you wash brushes in a sink or dispose of leftover paint, these same metals enter the wastewater stream. From there, they can accumulate in soil and waterways. Heavy metals don’t break down—they persist in the environment, harming wildlife and contaminating the food chain.
Safer alternatives now exist
Modern synthetic pigments generally surpass the brightness, permanence, and opacity of these ‘legacy’ heavy metal pigments, without the same toxicity profile. Painters should switch to these options for safety and ethical reasons.
However, heavy metal paints are still legal and still widely used. If you feel you must (and I hope you don’t), take the following safety precautions:
- Work in a well-ventilated room (open windows, use fans to exhaust air outside). Keep children and pets out of your painting area.
- Have a separate sink bucket for brush water—never dump pigment water into household drains. When the brush water has completely evaporated, dispose of solids as toxic solid-waste.
- Dispose of painting rags as solid hazardous waste.
- Wear nitrile gloves while handling paints.
- Wear a particulate mask while sanding and do so in a well-ventilated area.
- Use a palette knife to mix colors (you should be doing that anyway).
- Wear dedicated painting clothes, and don’t track pigment dust into your home.
- Wash your hands before leaving the studio or handling food or drink.
- Work in a well-ventilated space.
- Keep food and drinks out of the studio.
Doesn’t that sound like a complete pain?
Instead, why not use non-toxic pigments? They’re generally higher-chroma and less prone to fading anyway.
Here is a chart of toxic pigments and modern, non-toxic pigments:
Registration is now open for workshops in 2026! Reserve your spot:
- Canyon Color for the Painter | Sedona, AZ, March 9-13, 2026
- Advanced Plein Air Painting | Rockport, ME, July 13-17, 2026
- Sea & Sky | Acadia National Park, ME, August 2–7, 2026
- Find your Authentic Voice in Plein Air | Berkshires, MA, August 10-14, 2026
- New! Color Clinic 2026 | Rockport, ME, October 3-4, 2026
- New! Composition Week 2026 | Rockport, ME, October 5-9, 2026
Is this also true of watercolor paints Carol?
Yes, it is. Pigments are toxic across media, and it’s the pigments, not the binder, that’s the issue. In fact, the binder for oils is linseed oil, or flax seed oil, so edible.
Carrol, I really this need not be such a great concern for the average artist. Although I do agree with youthat disposal is an issue, and hazmat procedures should be followed, especially for larger quantities. But our wildlife and waterways are in a much higher risk from industrial pollutants and the incredible overuse of water from the upsurge of AI than they will ever be from artists. With good studio practice I think there really is no need to switch, and although you also make a good point about outsourcing toxic manufacturing for larger manufacturers, there are smaller ones that produce using appropriately monitored safety protocols right here in the states (e.g. Blue Ridge.) I think this is more of a concern for dry media that can be powdered, such as gouache and pastel, and thus inadvertently inhaled or ingested. Like the “water mixable”, I do wonder if this is something concocted by manufacturers to sell more stuff.
I have frequently said that I am less concerned about the impact on painters than the ethical concern of where pigments come from. We don’t make them in the US because of our own rigorous environmental and safety laws. Instead, we buy them from the developing world, where not only are there not good environmental or safety laws but they often use child or involuntary labor.
I started thinking about this initially after seeing a photo of a child worker covered with red cadmium pigment.
I have lived on property that gets its water from a well. I chose to continue with watercolors rather than acrylic paints as i was told when cleaning up from painting, acrylics left plastic residue. can you comment on this?
You can control that by letting your acrylic slop water evaporate. That leaves a solid that can be safely disposed of like any other solid.
But, yeah, I don’t think you should be dumping acrylic water into the soil. However, I’d say that’s not anything I’ve researched; it just makes sense to me.
Hi Carol,
I appreciate your list and am going to look thru and wean out some when i get home. (A few, ironically, requested by other teachers in their list to bring. ) As you know I also have had cancer (nearly 50 years ago now!!), and am extremely sensitive to chemicals due to a genetic condition.
However, I do like cobalt blue. I prefer paints from natural rocks as opposed to petrochemical ones. The majority of my paints are Daniel Smith paints which i believe are made in the US. I only paint outside, and never dump my paint into the sink.
I don’t use pesticides, no bug sprays, no synthetic detergents, no perfumes, (many known to be neurotoxins), no cigarettes, take no drugs (most made from petrochemicals), eat mainly organic, grow half my own food with only organic soil supplements, buy only organic seedlings, am myself building a home from all natural, non toxic materials – most i’ve sourced or produced myself, don’t use plywood, or particle board ( off gasses formaldehyde forever), have my own clean well water, was instrumental in getting a non toxic septic design approved and providers trained to use it in MA, don’t use aluminum pans, no teflon either ( a high school friend’s father who was a chemist involved in producing it forbid his family to use it due to the toxic amount of lead it leaches into food), live in the country with little traffic, no bleach, no lysol, no moth balls, no wifi in my home, use mainly herbs or homeopathic medicine or other alternative healing methods, chose my land to be a distance from high power lines, avoid x rays, and drive what most consider low mileage.
I love that you paired me with the chemist researcher above…we each pulled numerous items out of our luggage to find the other had brought this too…not following exactly the same route…but very similar (right down to same color pjs – totally irrelevant I know but amusing!) Any info on healthy living for our planet and inhabitants is worthwhile to share so we all can make healthy choices. So thank you for sharing this!
That pairing was pure serendipity; I had nothing to do with it!