A Deep Dive Into Non-Toxic Paints and VOCs

Paints that contain volatile organic compounds (VOCs) are associated with a host of health risks. Even though zero-VOC paint is available these days, traditional paints still dominate the market. We explain everything you need to know about VOC-based paints, so you can make an informed decision ahead of your next painting job.

Until recently, choosing a low- or no-VOC paint over one full of chemicals meant trading lower pollution for lower durability.  Most paint brands on the shelf in your local box store still contain Volatile Organic Compounds (VOCs), albeit at much lower levels than in years past.

What Are Volatile Organic Compounds (VOCs)?

Non-toxic paints, also known as natural or eco-friendly paints, are made with ingredients that are safe for both humans and the environment. By “safe,” I mean that they do not contain VOCs, strong chemicals that have been found to cause headaches, dizziness, visual and respiratory impairment, and even (with prolonged exposure) cancer. So if we know VOCs are bad for our health, why do paints contain VOCs at all?

The Back Story: Today’s Paint is Much Less Volatile

Before the Clean Air Act passed in 1970, levels of VOCs in some waterborne paints were as high as 3.5 lbs per gallon—not including the water content of the coating. The best you could do was look for a paint with lower VOC levels than a competitor. Today, most reputable paint manufacturers offer low-VOC paints in the >50 g/L range. However, this level is pre-additives. VOC content can go up dramatically when color pigments are added.

This chart is a rough approximation of the change in VOC levels in paints in the U.S. over time. Levels did not necessarily follow such an orderly descent, but you get the gist.

Why Aren’t All Paints Zero-VOC?

So why do paints contain VOCs at all? The answer is hinted at with the word “volatile.” VOCs are carbon-based compounds that evaporate quickly and easily at room temperature. That’s why manufacturers choose them—because no one likes to wait for paint to dry. 

VOCs in the form of binders or solvents help keep the paint in liquid form until application. Then, as you open the can and spread the paint thin, some of these VOCs fly rapidly into the air, contributing to indoor air pollution, sometimes along with strong odors and potential health risks. Some of the VOCs release more slowly into the air over a longer period of time and can potentially be more toxic to inhabitants. 

Painters like to work fast, especially when doing multiple coats. This table shows a hypothetical comparison of drying times for paints with different VOC levels, assuming a consistent temperature of 70°F, a relative humidity of 50%, and a smooth, non-porous surface. High-VOC paints tend to dry faster due to the rapid evaporation of solvents, while low or zero-VOC paints may take longer to dry.

It’s not that non-toxic paints won’t dry quickly. It’s just that you have to control the indoor environment more closely. Typically, that means keeping the room well ventilated (to reduce humidity), and keeping the temperature at an optimal 70-90 degrees. Different surface types will require different conditions.

VOCs Are Durable

Under certain conditions, higher VOC compounds may be desirable for high-stress products in your home, especially floors. For professionals, performance probably outweighs other concerns.But they ought to pay more attention to the health impacts. They’re the ones suffering the most damage from using products without proper protection. Non-toxic paint is more expensive traditional paint

For consumers, of course, price, combined with ignorance about VOCs, are major factors in purchase decisions. Looking at a $25/gal low-VOC can on the shelf next to a $50-$85 can of non-toxic paint, they’re thinking of the checkout line.

Non-toxic pain is less available than traditional paint

If you’re searching the shelves of your local paint store, you’ll notice it’s not always easy to find zero-VOC or no-VOC paints. You may have to go to a specialty paint store or order online when you get into the truly chemical free brands.

According to Current Trends in Interior Architectural Coatings, the percentage of painting done by DIYers increased during the Covid-19 pandemic, reversing a trend of many years. The U.S. architectural coatings market grew by 3.8% in 2020, with the DIY segment growing by approximately 15%. If you take into account the facts above about VOCs during applications, this growing interest from homeowners may boost zero-VOC paint availability.

The challenge with the more commercial brands is that most do not share the complete list of ingredients in their no-VOC or zero-VOC products. Some of these products have a strong odor during and even after installation.

Understanding VOC Emissions 

In order to better understand the health risks of traditional paints that contain VOCs, we need to understand how paints emit VOCs.

Research has shown that when finishes are applied in the factory under controlled conditions, allowing them to cure under heat and UV light, they emit almost no VOCs. In the case study I linked above, the total VOCs detected after 28 days were only 15 micrograms per m3, which is considered virtually VOC-free.

Of course, there’s still the “big picture” concern of releasing VOCs into the atmosphere at all, but in terms of how the coatings will affect your personal space, the faster the VOCs escape, generally, the less health risks.

On the other end of the spectrum are paints that release VOCs slowly.  A research paper titled "Watching Paint Dry I: VOC Emissions from Architectural Coatings and Their Impact on SOA Formation" found that most VOC release happens within 12 hours of application. 

They also found that flat and low lustre finish latex paints tended to cease off-gassing almost completely within a couple of days. High gloss finishes, however tended to continue off-gassing for 48 hours or more. 

A different study found that oil-based paints, which release 80-90 percent of their VOC load more rapidly than latex, can also continue to release VOCS for even longer. In general, darker colors of both latex and oil also tend to contain more VOCs, so these drying scenarios could become more intense.

You might be able to identify a VOC source with your nose (although some have no odor), but you can’t trust your nasal spidey-sense to measure how toxic they are. For example, as this table below shows, even powerful VOCs such as acetone may smell “fruity and sweet.” I remember my dad telling how much he loved the smell of gasoline. In other words, our bodies don’t necessarily know what’s bad for them.

So yeah, VOCs are a mixed bag. There’s no question they’re bad for your health. But their release from paints happens mostly during the application process, unless you choose gloss latex or oil-based products. 

If you still want that choice, wear a paint-grade respirator during the job. That’s typically a half-face respirator equipped with an organic vapor cartridge. Please buy it from a company other than 3M. That company continues to produce extremely toxic per- and polyfluoroalkyl substances (PFAS) and intends to do so until 2025, despite awareness of the extreme health risks these products pose.