Less Toxic Oil Painting Methods
For years I avoided working with oil paints because I thought they were toxic.
As it happens, a little more research turns up that they are no more toxic than other types of paint, and are actually less toxic than acrylic paints. Read on!
Less toxic alternatives to traditional solvents.
Many Artists are searching for ways to enjoy painting using methods that are lighter on the environment and less toxic to their bodies.
We can reduce toxicity by using fewer toxins overall when painting and cleaning up. Aside from the toxicity of the pigments themselves, we can consider the binder, thinners, mediums and cleanup methods.
Paint = pigment + binder
Pigments: Pigments come in powder form and must be mixed with something that makes them useable as paint.
Powdered pigment is mixed with a binder that allows it to be squeezed out of a tube onto your palette as paint.
Artist paints are made with a range of pigments that give them colour. The pigments used in artist grade paint are the same across all types of paint, whether water or oil based. (Different grades of paint (student v artist) are usually defined by the amount pigment used to make them, and the quality of the binder).
Pigments are common to all paints- no artist grade paints use different pigments for watercolour, acrylic or oil- they are all the same (check the labels!).
Some pigments are very toxic (like Cadmium- heavy metals) and some are much less toxic (earth pigments like ochre).
Binders: Watercolour and gouache use gum arabic, acrylic gouache and acrylic paint use acrylic polymer (which starts out white and dries clear- hence the colour shift when acrylic dries). Oil uses various types of edible, non toxic oils. Gum arabic is edible and non toxic. Acrylic polymer is neither edible nor non toxic.
VOCs, or Volatile Organic Compounds are the issue with paints and solvents. VOCs evaporate and enter the air as some paints dry. VOCs cause short term respiratory irritation and with long term exposure they can cause health problems that are more serious.
Acrylic paints release VOCs when they are drying, and oil paints do not.
Oil, watercolour and gouache (NOT acrylic gouache) do not release any toxins or VOCs as they dry.
Oil paints themselves are not inherently more toxic than other kinds of paints. The binder is a pure oil like walnut, linseed or safflower- all common edible oils. Linseed oil tends to have more of an odour than safflower or walnut oil.
Water soluble oils are made with a binder of oil that has been treated to make it soluble in water. It is neither more nor less toxic than traditional oil paints. The only thing that makes water soluble oils less toxic to use is the cleanup method, and you can thin them with water (although they tell you not to). Different brands have different textures when squeezed out, and some smell terrible (as do old linseed based paints where the linseed oil has gone rancid). I find the mediums for use with them can smell just as awful.
Material Safety Data Sheets (MSDS) are documents available for every product manufactured for use in homes, businesses and factories in North America. They detail the level of health hazard, how to handle the material safely, and toxicity levels in both the short term and long term. A quick google search will turn up the MSDS sheet for whatever chemical you are researching. The toxicity of most art materials can be assessed with a search for the MSDS sheet. We will focus on painting media.
TL;DR (a summary for those in a hurry!)
All paints use the same pigments, which range from inert (earth pigments) and non toxic to very toxic (cadmium based colours). The difference is in the binder, thinning methods, mediums and cleanup methods. Acrylic binder releases VOCs as it dries. Oil paints use nontoxic binders.
Solvent based mediums, cleaners and thinners are all easily replaced with non toxic products.
Paint Thinners and Solvents
Gamsol by Gamblin is a solvent based thinner with very low toxicity. That isn’t to say it is nontoxic, but it is a low VOC form of solvent. It falls under the OMS or odourless mineral spirits designation.
It has been processed to remove most of the aromatic solvents that would otherwise make it toxic. You can use it safely in small amounts in an ordinary closed studio. If used only for thinning small amounts of paint in the initial stages of sketching onto your painting surface, it is quite safe. In large amounts spread over a canvas, it is likely to be a bit more toxic, although its toxicity rating is very low (1).
Turpentine is highly toxic and should never be used in closed areas. Turpentine is what was used historically. It gave oils their toxic reputation.
White spirits/odorless mineral spirits/OMS from the hardware store are similar to Gamsol, but Gamsol has been further refined to remove more VOCs.
Low Toxicity Oil Painting
Low toxicity methods aim to protect us from toxic pigments and limit our exposure to solvents.
Read the labels of your paints. Each will list the pigments used, and you can choose less toxic forms of various colours. For example, you can choose “Cadmium free” hues.
Wear gloves (especially during cleanup) to keep pigments off your skin, and wash immediately if you get it on your bare skin. Keep your studio clean so you don’t get paint on your clothes, and store used paper towels and rags in closed containers (a garbage bin with a lid).
Use solvent free mediums, if you use mediums.
Use willow charcoal, pencil or chalk for your initial sketch, or use acrylic paint for your sketch and underpainting. Note: acrylic paint can be more toxic than oil paint, it releases VOCs as it dries. Be especially careful when diluting with a lot of water. Open a window or use an air purifier.
Clean up with soap and water. Sunlight laundry bar is a very effective cleaner. This will prolong the life of your brushes too, as cleaning with solvent can dry out the bristles. Rosemary & Co brush company recommends soap and water cleanup.
Use a good quality air purifier in your studio with a filter rated to remove VOCs, and open windows as often as possible to bring in fresh air.
Solvent Free Mediums
Solvent free mediums are readily available (Gamblin, Sennelier) and have no odour. They should be used not as thinners in the initial stages of a painting, but as extenders/glazes at the end. The fat over lean rule for oil painting is that thinner (no added oils or mediums) layers should be used initially, as they dry more quickly and can be safely overlaid with non thinned paint from the tube in the middle stages. Mediums and oils used to thin the paint should be reserved for the top most layers to prevent cracking. One exception is the addition of a drop or two of oil to make the paint more buttery when it is squeezed out of the tube.
Air Filters
I have a powerful air filter in my studio next to my painting area. There are plenty of options at various price points. This is the one I have. Look for one that removes VOCs.
I have the "Overreactor" level for the studio. When I use acrylic paint in large amounts or with a lot of water, I get a high VOC alert from my air purifier. When I use oils, even with small amounts of Gamsol, I get no alerts. Hmmm.
Other options:
Open a window while you work, and while your acrylic paint or solvent-diluted paint dries.
Always use soap and water for cleanup.
Keep your studio clean, both while you work and in between.
Dispose of rags and paper towels in a covered container and remove regularly.
Brush Cleaning and Palette Cleanup
I use Sunlight Laundry Soap in bar form for cleanup. It does a very thorough job. I gently scrub my brushes over the surface of the bar, getting them nice and sudsy, then I set them aside while I do the same to my other brushes. Then I scrub each one in a circular motion on my gloved palm, rinse and repeat until all the pigment is gone. I then wipe dry with a paper towel, reshape, and leave them to dry. Some brushes need extra attention at the ferrule to get all the paint out.
I have tried Murphy’s Oil Soap, Dawn dish soap and The Master’s brush cleaner. None are as effective as Sunlight Laundry Soap. Some are closer than others, but Sunlight gets my brushes clean enough to go from oils to acrylic and back without issues.
I use a glass palette, painted mid grey on the back. This cleans up very easily with a palette knife to scoop up leftover paint (which I store in the fridge in a sealed container) and to finish up with a scraping blade to get the last of the paint off the glass. I then wipe with a dry paper towel or one with a small bit of Gamsol on it.
Toxicity While Drying/Curing Finished Paintings
All paint mediums “dry” or cure to their final state.
Only acrylic paints give off VOCs as they dry, but this is a pretty fast process so with an air purifier and/or an open window you can clear the air of VOCs.
Gum Arabic binders release no toxins, and oil paints release no toxins as they cure.
More About Gamsol
The MSDS Sheet for Gamsol:
https://gamblincolors.com/wp-content/uploads/2016/03/SDS-Gamsol.pdf
Gamsol is not considered a health hazard, as its rating is minimally toxic. It is, however, a petroleum distillate, so we really don't want to breathe it in. It has been refined to remove most of the VOCs (the harmful part), so in the small amounts used by oil painters it can be considered of very low toxicity.
Happy Painting!
Get out and experiment with those oil paints and breathe easy!
Barbara