Acrylic vs. Oil: VOC

In this series of articles, I’d like to look at these two mediums from a professional and responsible artist’s point of view, thinking about the artwork itself and the impacts that working with these mediums includes. There is no straightforward answer to what’s better and I don’t think such a question can be valid; this article is aimed to make an informed choice for this or that art project. I’ll try to be as straight to the point as possible.

What is VOC? 

Volatile organic compounds (VOC) means any compound of carbon (excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates and ammonium carbonate) that participates in air. Some VOCs have a distinct smell, while others may remain unnoticeable. Exposure to VOCs in indoor air may affect your health, depending on which VOCs are present, the level of VOCs present, and how long you are exposed. 

Some examples of VOC include formaldehyde, benzene, ethylene glycol, d-Limonene, toluene, acetone, ethanol, 2-propanol (isopropyl alcohol), methylene chloride, tetrachloroethylene and many others.

The World Health Organization (WHO) recommends a guideline value of 0.3 mg/m³ for total VOCs in indoor air.

Both oil and acrylic paints (we’re talking about artist paints, not industrial) emit VOC, but in different quantities and in different ways. You can find the information about VOC in the Material Safety Data Sheets (MSDSs) that most manufacturers provide. 

MSDS for the same product vary depending on country regulations and usually split based on pigment groups:

• containing cadmium and cobalt
• containing zinc oxide
• and all the rest
• These extracts refer to “all the rest” based on regulations in the same country and state (county).

Before we refer to the facts, let me ask you a question, Which paint would you choose, the first or the second?

“SECTION 7: Handling and storage  

7.1. Precautions for safe handling Precautions for safe handling: Ensure good ventilation of the workstation. Wear personal protective equipment. 

Hygiene measures: Do not eat, drink or smoke when using this product. Always wash your hands after handling the product.  

7.2. Conditions for safe storage, including any incompatibilities Storage conditions: Store in a well-ventilated place. Keep cool.”

“SECTION 7: HANDLING AND STORAGE 

Precautions for Safe Handling: Read and observe all precautions on the product label. Wash hands after use. Immerse contaminated rags in water. 

Cautions for Safe Storage: Store away from high temperatures, sparks, or open flame”

I’m not sure what would you prefer, but I’m voting for the second. The first one describes acrylic paints, and the second one refers to oil paints (I’m not disclosing brands here). 

Even very high VOC in paints doesn’t qualify to be labelled “toxic” as VOC compounds do not stay in your body for long being broken down and released with urine. However, prolonged exposure to VOC vapors can cause a variety of health effects, such as:

• eye, nose, and throat irritation;
• headaches, migraines and loss of coordination;
• nausea and damage to the liver, kidneys, or central nervous system.

VOC in Oil Paints

In general, the VOC of artist oil paints (not industrial ones that you buy in construction stores) is less than 2 g/l. Meaning, for example, if you’re painting in lean technique and use 10 ml of paint, which is about a tablespoon size, your paint will emit about 20 mg of VOC and to maintain healthy standards 66.7 m3 of room space is needed. If your ceiling height is 2.5 m, a painting room should be 26.6 m2 or larger to maintain healthy balance.

If you’re painting in impasto technique, you’ll need a room about 10x larger. 

However, oil paint releases VOC slowly, while paints dry, meaning that the concentration of VOC will be lower than those estimates.

To keep oil painting safe, just don’t use or add turpentine oil or solvents. They have almost 100% VOC, reaching up to 1200g/l. Use linseed or other drying oil, solvent-free mediums, cleaners and varnishes. Keep your painting on the safe side.

Cheap oil paints may have solvent inside and emit more VOC.

VOC in Acrylic Paints

Generally, the VOC of artist’s acrylic paints is about 50g/l. For a lean technique, let’s use the same 10ml of paint. They will contain 500 mg of VOC and with the WHO’s norm of VOC level 0.3 mg/m3 we’ll need 1666.7 m3 of space, which is about 667 m2. If you paint in the impasto technique, multiply this number by 10.

The good news is that all VOC is emitted during drying time, which is quite fast and after the painting is cured, the VOC level is 0. In other words, in 1-2 days air quality with proper ventilation and filtration goes back to normal.

To compare, acrylic paints that contain mica powder (in other words, all metallic paints) have a VOC of about 300 g/l, and acrylic varnishes have 100 g/l. I saw artist’s acrylic products with VOC 500 and higher. Some acrylic gels and pastes may have very low VOC as no pigment or excessive water was added.

Acrylic dispersion/emulsion itself has a very low VOC. Making acrylic paints by yourself and using them right away is another solution to avoid intoxication. What is inside acrylic paints and why, you can read in the previous article.