Dear Artist: Understanding proper use of painting solvents and mediums is the key to safe studios. While toxicity of solvents and mediums is critically important for oil painters, I would like to focus this article on artist's pigments.

After talking with painters for 25 years, I realized that many artists believe that "oil paints are hazardous and acrylic paints are not hazardous." I always respond: I would eat any color in oil before I would eat that same color in acrylic.

Think about this: Ultramarine Blue oil color is made from ultramarine blue pigment (complex silicate of sodium & aluminum PB29) ground into vegetable oil (linseed oil, poppy oil or safflower oil). Ultramarine Blue acrylic color is made from the same ultramarine blue pigment ground into plastic. The linseed oil is a component in my dog's food; the plastic is what the dog dish is made from!

So color for color, the pigments used in artists' colors are not necessarily hazardous. Linseed oil is naturally occurring vegetable oil. Perhaps because acrylic paints can be diluted with water, artists think using them is safer (of course, not for the environment. I do not recommend artists wash any materials down the drain). But no doubt, water is much safer than solvents. This is why my concerns for studio safety have always focused on solvents. By using Gamsol and other high quality brands of odorless mineral spirits, artists can reduce their exposure to solvent to levels that are permissible and still enjoy the pleasure and challenge of working with oil colors.

Historically, painters have been exposed to much higher levels of toxic pigments than painters today.

Lead based pigments: The root of the simplistic notion that "oil paints are hazardous" comes from the use of lead based pigments. Until the 20th century, lead whites (Flake White, Cremnitz White) were the only white pigments available that were reasonably opaque and with which artists could create impasto. In the 1800's, Zinc oxide pigment was first ground into oil. But because of Zinc's transparency and tendency to dry slowly, it was not a good replacement for lead white. So lead white continued to dominate oil painting until the mid 1920's when non-toxic Titanium White (titanium dioxide pigment) began to take over the palette.

Some artists continue to use lead white because of its interesting working properties. Lead whites, in general, are characterized by a heavy texture, slightly warm color, more opalescent than opaque in thin applications. Titanium White is the most reflective pigment—97.5% of available light that reaches the pigment is reflected. This most opaque white oil paint which has a lighter, more buttery paste than lead, and the most brilliant of the white pigments.Working with painters who wanted a non-toxic option to lead white, I painted with it for a few years and came to appreciate its unique working properties. Over the next few years, I formulated Flake White Replacement—a heavy dense paste, very lean (a good under painting color), slightly warm in color, non-toxic, less opaque and more opalescent than Titanium.

In addition to white lead, lead based compounds were the base of a number of warm colors on artists' palettes such as Lead Tin Yellow, Chrome Yellows and Red Lead.

Most of these colors were made obsolete by the creation of Cadmium Yellow in the latter part of the 19th century. Because Cadmium Yellow pigments were more expensive, they did not completely push lead based yellows off most palettes until mid 20th century. Today it is nearly impossible to find Chrome Yellow in any manufacturer's line of color. The Cadmiums are just as opaque, possess a much cleaner color, and have a much lower level of toxicity.

Cadmium pigments: In the hundred years since their first manufacture, cadmium pigments now have a very low level of bio-available cadmium metal in their chemical composition. Unfortunately, many painters still consider Cadmium artists' colors highly toxic. If Cadmium pigments were made from cadmium metal they would be highly toxic. Cadmium pigments are actually made from cadmium compounded with sulfur for the Cadmium yellows (sulfur and zinc for Cadmium Lemon and Cadmium Yellow Light). To make Cadmium reds and Cadmium oranges, cadmium is compounded with sulfur and selenium.

American manufacturers of cadmium pigments have developed production systems that yield cadmium pigments that are relatively insoluble in the human digestive system. They have been so successful that Gamblin Cadmium Oil Colors DO NOT REQUIRE an ASTM health-warning label for ingestion. Over 25 years ago when I first started making oil colors, cadmium pigments were much more soluble in the human system than they are now. Cadmium pigments contained about 1000 parts per million (PPM) bio-available cadmium. Now cadmium pigments that I choose to make Gamblin Artists Colors contain only about 5 PPM cadmium that can be absorbed through ingestion.

European brands sometimes carry health warning labels if the Cadmium pigments used come from a factory that cannot meet these standards. Cadmium pigments remain hazardous if they are inhaled. I recommend you use a NIOSH dust respirator if you sand surfaces made with a high percentage of Cadmium colors. Inhalation exposure can also occur while making paint by hand grinding cadmium colors. But there is no dust or fumes that come off paints from the tube.

Cobalt Pigments:

Cobalt Blue is a compound of cobalt and aluminum. Cobalt Green is a compound of cobalt and zinc. Oil colors made from these compounds do not carry health-warning labels because the cobalt cannot be readily absorbed into the body. Just like when using Cadmiums, artists should not inhale the dust from cobalt pigments.

If you have any questions concerning studio safety issues, email me at RobertGamblin@gamblincolors.com

Sincerely,
Robert Gamblin