"It’s hard to imagine painting without cadmium. The brilliant, lightfast pigment was discovered around 1820 and started appearing in artist’s red, yellow, and orange paints in the 1840s — just in time for Impressionist founder Claude Monet’s arrival in the world. They’re what gave us Monet’s haystacks, Van Gogh’s sunflowers, and Matisse’s red-drenched studio. The European Chemical Agency (ECHA) began considering a ban on cadmium after the Swedish Chemicals Agency submitted a 197-page document calling for one in December 2013. Cadmium pigment is made with cadmium sulphide, a toxic heavy metal. It is not technically classified as hazardous by REACH, the EU body that advises the commission on chemicals, and it makes up only .1 percent of paints. Nonetheless, the report argued that artists were polluting the environment by rinsing their cadmium-soaked brushes in the sink. The cadmium would find its way into sewage sludge that is spread on agricultural land and wind up polluting crops, and so increase the risk of cancer and other illnesses."
Thursday, April 11, 2019
Cadmium Pigment Escapes E.U. Ban
The European Union has thrown out Sweden's proposal to ban cadmium paint.
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To be fair, heavy metals are a nightmare in sludge treatment and disposal, which in turn is one of the most difficult and expensive parts of sewage treatment. If the cadmium in paint really did make a difference to sludge toxicity, it would cost municipalities HUGE amounts of money when they're forced to pay for safe disposal (which is seriously expensive), instead of getting farmers to take safe sludge for free as fertilizer.
Luckily for artists, their contribution to cadmium content in sludge turns out to be tiny. Here's a 2016 scientific study that shows the numbers.
I haven't bought any cadmium (or cobalt) colors in the last years. For watercolor, where transparency is more a virtue than a problem, I would say that replacing cadmiums is rather easy. For oils it's certainly more difficult. I don't use much the bright/vermillion-like red, so pyrrole red (PR254) is enough for me (although it seems to mix a bit worse); replacing the yellow has been harder, but with PY154 (more transparent) and PY74 (more opaque) I'm now satisfied. Actually the color I miss more is cobalt blue, because no other blue has the same luminosity for painting skies.
I guess sooner or later cadmium colors will be banned: in the end, I think artists have no special right to pollute our poor planet. Color companies are getting ready, both Liquitex and Winsor&Newton (and possibly others) produce a set of cadmium replacements; but as far as I can see, none of them explain which pigments are used, which is odd.
Hopefully, someone with a cooler head pointed out to them that 99.99999% of the cadmium in landfills is from NiCad batteries, not artist's pigment. I can easily do without Cadmium Reds — I prefer Pyrrole Red anyway — but there's no real replacement for Cadmium Yellow. No other yellow is as strong, as opaque, or — to me, anyway — as beautiful.
I was a professional chemist for over 40 years before taking art lessons as a hobby; I am glad to see common sense in these first three comments. Cobalt is not particularly dangerous and is an essential element (Vitamin B12). Chromium is probably worse than Cadmium, but as pointed out... paint brushes aren't a big source. Heavy metals will concentrate in the sludge, and so it is best avoided in food agriculture. I grew up in West Texas and there was a bigger problem with Arsenic being used to defoliate cotton. People worried, but I never heard of anyone dying from it. There are always going to be heavy metals in air / soil. Life is all about risk assessment. Organic substitutes have to be manufactured, and that raises other problems... except for maybe Indian yellow which is naturally made (but still has to be concentrated and put into tubes)...
There are attempts in the EU as well to ban certain homeopathic medicines...due to toxic ingredients...;-(
I haven't bought cadmium paints in a while, but I still have a few tubes I use sparingly. Have you tried Winsor & Newton's cadmium-free paints? I've been wanting to try them, but I haven't yet.
The Swedish study estimates the contribution of paints to total cadmium in soil up to 2%, which is still small but larger than 0.01% or so. But my opinion is that I should try to reduce pollution whenever I can. There are numberless small sources of pollution which sum up to make a large contribution. In my opinion there are usable alternatives (of course, we must be sure that the alternatives are less polluting than cadmium, which is not always obvious). Lead white is probably the best white available, but we all managed to use titanium white, so I think I can live without cadmium pigments as well.
I want to stress that I don't like to preach, that's just my choice and I appreciate other people's views.
One more comment regarding Chromium. I sometimes use PG17 (Chrome Oxide green). As far as I understand, Cr(VI) is very poisonous, but Cr(III) (the one in PG17) is relatively safe. Any information would be appreciated.
Speaking as a chemist... Regarding Chromium III vs Chromium VI.... There is not a lot of definitive data; but as you stated Chromium III seems safer, and perhaps a necessary trace element as it is commonly found in soils and plants. The different electronic states (III, VI, etc.) give Chromium its color... i.e. Potassium Chromate is Purple and Chrome Oxide is green, etc. Since painting is a part time hobby for me... the organic substitutes are fine.
I let my water sit overnight or even a day or two, using fresh jars in the meantime. much if the pigment settled to the bottom. As I pour it out, I cover the top with a paper towel (the stronger Viva cloth). That catches more of the pigment, then I use the towel to wipe the pigment sediment from the bottom & sides of my jar. Dump it in my hazard recycle pile for an eventual trip to hazardous waste collection along with batteries, house paint, stain cans, whatever. Anyway.. less goes into our water
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