Are Oil Paints Toxic? Yep.

I once watched a video of an art professor put oil paint on her salad and then eat said salad in order to prove that oil paints are non-toxic...

Except, she was wrong and oil paints are totally toxic. Have they become less toxic as paint technology advances? Yes, they have, but that doesn't mean we should be eating them. Here I will be going over first, why not to eat your oil paints outside of them being toxic or not, and then the three main reasons why oil paints are toxic and how to protect yourself from their toxicity. Spoiler alert, its really easy to protect yourself.

Do not Eat! That goes for you too Van Gogh

First off, the oil (be it linseed, walnut, safflower, etc) in oil paints is not food grade and has been chemically processed. Second, the paint was mixed in a non food safe environment. Third, the paint has been sitting in a metal tube that has been heated and cooled and shipped and stored for who knows how long. So no, its not safe to eat paints.

BUT! Oil paints are not a problem as long as you know the dangers, because knowing is half the battle. Let's talk about it...

What Makes an Oil Paint Toxic: The Three Main Reasons

First a quick warning from Winsor and Newton:

• Winsor & Newton Artists' Materials do not present any major hazard when used with care and common sense. It should, however, be emphasized that as with other chemical products, high standards of general hygiene should be adhered to, both during and after use of these products and warnings given on individual products should be followed. Prolonged contact with the skin and ingestion (or swallowing) of the product should be avoided. This includes avoiding practices such as applying colour with the fingers or pointing brushes in the mouth. 

1. Oil paints dry by Oxidation and not by Dehydration

The reason oil paints take so long to dry is because they dry by a process called oxidation, whereas watercolor and acrylics dry by dehydration.

As watercolors dries, heat enters the paint film and releases oxygen and hydrogen. This physical reaction leaves the dry paint behind. In oil paint, oxygen has to enter into the paint film and this creates a much more complex chemical reaction. Heat is released along with free radicals and some carcinogens (cancer causing chemicals) such as VOC benzene. If you would like to know more about this very interesting process, watch the video below:

Oil paints do not release such large amounts of VOC benzene that there is a huge cause for alarm, however, it is important to be aware of the process and that ventilation is important.

How to Protect Yourself:

Avoid sleeping in your painting space, do not allow oil paints to remain on your skin for long periods of time, and do not eat, drink, or smoke in your painting area. Use house plants that specifically remove VOC benzenes such as peace lilies. You can read more about other plant options here.

2. Toxic Oil Paint Pigments, specifically Cadmium and Cobalt

I once read someone trying to prove that oil paints are not toxic because the pigments are naturally occurring earth minerals, and are therefore safe. Well, uranium and plutonium are also naturally occurring...so there is that? Another point that is important to know is that a lot of modern paint pigments are made via chemical processes and are not naturally occurring.

The pigments below are considered carcinogenic (cancer causing):

• Highly Toxic Pigments/ Known or Probable Carcinogens:

  • Burnt and raw umber; cadmium red, orange, and yellow; chrome green, orange,

    and yellow; cobalt violet and yellow; lead or flake white; naples yellow.

• Moderately/ Slightly Toxic Pigments: 

  • Alizarin Crimson; cerulean blue; cobalt blue and green; chromium oxide green; prussian blue; zinc white.

These pigments cause the most harm in their powdered form, where they can be inhaled. However, the oil in the paint allows for the pigments to also be absorbed through the skin. Personally I have always wondered if the reason several of the great impressionists suffered from intense arthritis is due to poor paint hygiene practices. Like in this image of Renoir.

Cadmium and cobalt are the primary pigments you need to look out for; however, your skin only absorbs a small amount of cadmium and cobalt at any given time. Be aware that cadmium is an accumulative metal and will slowly build up in your system. When absorbed it takes the place of zinc in hemoglobin and can cause some eventual damage.

How to Protect Yourself: 

You can swap out your oil paint brand for cobalt and cadmium toxic free brands, such as Gamblin and Winsor and Newton.

You can eliminate cadmium altogether by replacing it with hansa yellows, reds, and oranges. And several brands now make their flake whites and naples yellows without lead. However, always check your paint brand's lead information.

For all other paints, be aware and make sure that you always wash your hands, do not put your paint brushes in your mouth, and if you want to be extra careful you can always wear disposable gloves while painting. Which a lot of artists do, by the way.

If you are really into deadly paints, you can read more about toxic paints in the book Radium Girls. So good.

3. Watch out! Oil paints can spontaneously combust! 

Technically this is true. Oil and solvents left on a paper towel or rag will still continue to oxidize, which creates heat, which can cause said paper towel or rag to combust! I have never seen this happen, I have never heard of it actually happening, but technically it could happen.

How to Protect Yourself: 

Put your rags in a metal canister that is filled with water. Which I have also never seen anyone do. However, you should probably not smoke (unless you are Pollack or someone of that sort) or light things on fire in your painting area just in case.

So what do you think? Have I made enough of an argument to convince you that oil paints are toxic? If not, let me know in the comments and I will see what I can do.

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I hope you have a great day and Happy Painting!

This is a rewrite of my original blog post, Are Oil Paints Toxic? Yep.

For more about painting check out my main Tips and Techniques page.