What is low-VOC paint?

Heather Benjamin
June 21, 2017
Paint & Coatings

Choosing paint for your home that is safe for your family and indoor air quality can seem like a mystifying quest. Is there a real difference between "low-VOC" and "zero-VOC"? What is "off-gassing"? If you choose the safest kind of paint, will it stand the test of time?

Here's a breakdown of the factors involved in buying green paint.

VOCs

Volatile organic compounds, or VOCs, are carbon-containing substances that easily become vapors or gases. They can be present in paints, coatings and cleaning products.

In coatings, the solvents containing VOCs assist with the quality of application and drying, so that a substance like paint does not streak on a surface. However, they can cause respiratory and other health problems for occupants, when used indoors. Their release into the indoor atmosphere is called off-gassing, and it occurs over time, not just during paint application or drying.

Paints labeled "low-VOC" should contain fewer than 50 grams per liter of volatile compounds, if they meet the Green Seal standards. Since there is no one regulatory standard, the low-VOC designation means different things depending on which body is certifying it, but 50 grams is the common bar for architectural flat paints. You can compare standards for other types of coatings in the influential South Coast Air Quality Management District Rule 1113. Most low-VOC paints are latex-based. Adding pigment to a paint base may also increase its VOC levels up to an additional 10 grams per liter.

Paints labeled "zero-VOC" may actually contain a small amount of VOCs—usually fewer than 5 grams per liter. There are also completely natural paints, such as milk paint or chalk paint, that carry no VOCs.

Durability

Sometimes, you have to make a trade-off: lower VOCs for more frequent paint applications. The substances that can make your paint more toxic are also sometimes the ones that cause it to dry faster and to stick better, for longer. For example, if you apply milk paint to your nursery wall, it may take several days to dry, and may need to be recoated sooner.

However, paint formulations are always changing and improving. Chances are, the paint you buy today has already solved some of the formulation hurdles of two years ago. Companies are increasingly focused on creating more low- or zero-VOC interior paints.

Resources

As paint formulators balance the needs of human health with those of durability, they come up with better products, so it's worth staying on top of the latest by looking for online resources of top products and checking with approved lists from GreenSeal and GreenGuard.

Learn more about selecting green paint

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