This article on oil paints is by Michael Skalka, chair of the subcommittee on artist’s materials for ASTM International. It first appeared as the Ask the Experts column in the November 2009 issue of The Artist’s Magazine.
Q. I’ve heard people say that painting with traditional and water-soluble oils poses health hazards for the painter. Some say even people with whom the painter comes in close contact, such as family members, are at risk. Just how safe or unsafe are oil paints?
A. Traditional oil paints are basically a drying oil and pigment. Manufactures also add stabilizers because modern paints need to be stored for a considerable length of time before use. Stabilizers keep the oil from separating from the pigment. Let’s consider the safety of each of these components:
1. Drying Oils
Drying oils used in artists’ paints are mainly linseed, safflower, poppy or walnut. We know that linseed oil is safe to work with because we can buy specially processed food-grade quality linseed oils in health food stores as a great source of omega-3 fatty acids. The health food industry uses the term flaxseed oil in reference to the plant from which we derive linseed. We use both safflower oil and walnut oil in cooking. Poppy oil doesn’t appear to be popular in the health food realm, and references point only to its use in paints; however, manufacturers do use it in skin care products.
The stabilizers, if used, are metallic fatty acids. Because they’re mixed into the paint, they do not pose an independent threat to a person using an art material.
3. Soaplike Substance
Water-soluble oils contain an ingredient that would be considered close to soap, which makes water combine with the oil for assistance in cleanup.
Regardless of the origin of the oil and any additives, you should not consider paints safe to ingest. Keep them on the palette and the painting, and they’ll pose no unusual health risk.
Pigments can be as benign as common dirt or as harmful as many other chemicals are to the human body. Many of the paints used by artists from the Middle Ages to the late 20th century had varying degrees of toxicity. Even today, while the most highly toxic pigments have disappeared, no pigment should be considered nontoxic. The one property that makes oil paints so safe to use is that the pigment is bound in a liquid vehicle (the drying oil). Therefore the problem of dry powder finding its way into artists’ lungs or flying about and landing on their families’ food is eliminated. Even the nastiest of pigments, which no longer are readily available, wouldn’t give off toxic vapors or be otherwise harmful unless taken directly into the digestive system by mouth or, in the case of some pigments, they came in direct contact with unprotected skin.
Safe-Use Practices for Oils
Q. What safety precautions should I follow when painting with oils?
A. My recommended safety precautions fall into two main areas:
1. Keep paint and solvents off your skin.
I would remind artists that repeatedly allowing oil paints to splatter on their hands and arms is a bad practice. That’s especially true when an artist removes paint from the skin with a solvent. Skin, the largest organ of the human body,
is a sponge for taking in substances. Unbroken skin may be good at repelling germs, but an artist negates that protection when he or she tries to remove paint from skin using a solvent-soaked paper towel. Skin absorbs solvents, and when you mix paints with a solvent, the paint can enter the body as well. When using oil paints, slathering paint on oneself and cleaning it off with solvent poses the greatest risk.
Common sense and careful studio practices are crucial to keeping the paint on the painting and off the body. My advice to painters who display a tendency to get paint all over themselves is to wear disposable gloves and to protect other areas of the body with clothing or an apron. When oil paint does get on the skin, remove the paint with plain soap and water. Painters who hate gloves should at least use a barrier cream, sold in art stores, that provides some degree of protection against paint components entering through the skin.
2. Paint in a well-ventilated area.
Use extra caution with paints classified as alkyd quick-drying colors. Unlike traditional oils, these contain a small amount of odorless solvent; you should not use these in a closed studio space unless you outfit that space with continuous airflow and exchange. When you use alkyd colors outdoors or in a well-ventilated studio, handle them in the same way as traditional oil paints.
Many artists, of course, don’t have studios, and some admit to painting in their kitchens. This is one place where food and painting materials have too great a chance to interact. In addition, the potential for fire rises when solvents come into close contact with cooking appliances. If possible, set up a painting area in another part of the home where you can establish ventilation that constantly changes the air in the space. As I’ve explained, when it comes to poor ventilation, the problem generally isn’t so much with the paint as with the solvents the artist uses for cleanup and paint dilution.
Most artists use oil paints for many years without ill effects. Follow the few safety precautions I’ve mentioned above, and all should be well.
Waste Management for Oils
Q. How can I safely dispose of oil painting materials?
A. you can easily and safely control the disposal of unused paint and solvent in a home environment. Use a closed metal solvent can, just as plein air artists do outdoors.
How to Use a Solvent Can
Open the can only when necessary and close it immediately after use. Wipe excess paint onto disposable paper towels before using solvent to clean brushes. This makes your solvent less prone to becoming overly dirty with paint. The solvent not only lasts longer, but you decrease your exposure to the solvent because you can clean your brushes quickly. Place the used paper towels in the closed metal can.
What to Do When the Solvent Can is Full
When the pigment waste in your plein air solvent can accumulates to the point of coming close to the bottom of the inner basket, it’s time to clean the solvent can and dispose of the pigment in the container. Let the can sit for several days until the pigment waste has settled to the bottom and some clear solvent remains on the surface. Slowly decant the clear solvent into another container for temporary storage. (You may want to purchase a second solvent can to use in tandem with the first one.)
Remove the inner basket from the solvent can containing the pigment waste. Pour the pigment sludge onto a flat piece of aluminum foil folded around the edges to create a shallow pan. Make sure you support the foil with a palette or sturdy piece of cardboard. Let the sludge dry outdoors in a safe place that won’t be disturbed. Fold the aluminum foil around the dry sludge, and take it to your local waste processing facility for disposal. Many counties have paint and hazardous waste reclamation programs for properly disposing of these types of materials.
Another option is to let the paint waste dry and then mix it with an alkyd medium to make a paint-like material that you can use to tone canvases or panels for future paintings.
With an adequate, well-ventilated space and a waste disposal method that limits solvents escaping into the studio, a family can live safely with an oil painting artist.