Healthier Paints Mean Healthier Interiors
Low and no VOC paints contribute to better indoor air quality.
The indoor air quality (IAQ) in commercial and institutional facilities can have a significant impact on the health, comfort, and productivity of employees. Even the best maintained facilities can have issues with poor IAQ.
The problem is that there are numerous sources of indoor air pollution. Some of these may be introduced into the building from the outside by the ventilation system, or by open windows. Others are generated by operations conducted within the building itself. Still others are introduced by the building materials used in the construction of the facility. One pollutant that is gaining more attention by building managers and owners is the presence of volatile organic compounds (VOCs).
The EPA defines VOCs as being organic chemical compounds that can evaporate under normal indoor conditions, known as off-gassing. While they often have an odor that is easily detected, not all VOCs can be detected by smell. And while the rate of off-gassing is highest when the item is new, for some items it can continue for the life of the item. The concern for building owners and managers is that VOCs can have both short- and long-term health effects on building occupants. Short-term effects include headaches, burning eyes and throats, coughing, and breathing difficulties. Long-term exposure effects include possible damage to the liver, kidneys, and the central nervous system.
One of the biggest sources of VOCs in buildings is the paint applied to interior surfaces. All paints are a combination of three classes of components: pigments that give the paint its color, binders that hold the applied paint together, and carriers that help to evenly distribute the paint. Combined, they can include a host of hazardous chemicals that lead to VOC off-gassing, including formaldehyde, benzene, ethylene glycol, and fungicides.
Latex paints offer some advantages over oil paints. While oil paints use an organic solvent that is a major source of off-gassing, latex paints are water based and do not use as many organic solvents. However, that does not mean that they are VOC free. Latex paints contain a number of components that do off-gas VOCs, including quick drying, conserving, anti-bacterial, and anti-mildew agents. So while most latex paints are not VOC free, they off-gas far fewer VOCs than oil based paints. For example, a typical can of flat, interior latex paint contains about 150 grams of VOCs per liter. The same gallon of oil based paint has approximately 350 grams per liter.
The most noticeable off-gassing occurs when the paint has just been applied. The typical smell one notices when entering a freshly painted room is the result of VOC off-gassing. While the smell will fade with time, the off-gassing continues well after the paint has dried. Although lab tests have been conducted to try and determine when the off-gassing falls to a negligible level, they have been inclusive and, in general, not applicable to real world conditions. However, it is accepted that the levels of paint-based VOCs present in a space do fall to low levels in about three months, even though they have been detected for as long as three to five years after application.
Low and no VOC paints
Maintaining acceptable IAQ has been a concern for building owners, managers, and occupants for several decades. Changes have been made to HVAC system operations to improve ventilation. Cleaning and sanitizing products and practices have been modified to reduce exposure of building occupants to harmful chemicals. Even the selection of such components as building furniture and floor finishes has been impacted. But these are not the only contributors to poor IAQ. Attention has also turned to the paint used and its contribution to poor IAQ.
Paint manufacturers have addressed the concerns of building occupants and managers by introducing a number of products that are designated as being low VOC or no VOC. Almost all of these paints are water based. And while they are labeled low or no VOCs, they all still contain some VOCs — just at much lower concentrations than found in other paints.
A concern when selecting paint is what the U.S. Environmental Protection Agency (EPA) considers to be a VOC. The VOCs measured in paint and listed on the label do not actually include all of the VOCs present. The problem is that the EPA defined VOCs to include only those chemicals that contribute to the formation of smog. For example, neither ammonia or acetone are considered to be a VOC since they do not react with sunlight and other pollutants to form smog. But they and other VOCs may be present in paint and will contribute to poor IAQ. They simply are not counted in the paint’s VOC total.
Fortunately, there are several organizations that have established testing and certification programs that take the confusion out of what is and isn't a VOC, and how much can be included in a can and still consider it to be low or no VOC paint. Two of these organizations include Greenguard and Green Seal (see below). Both are nonprofit, industry independent organizations that offer certification programs for products that meet strict standards for low emissions, including paints. Products are tested for a wide range of chemical and VOC emissions before they can be certified. Look for these certifications on the paint label to confirm that the contents meet the VOC content standards.
To be considered low VOC, the paint must contain no more than 50 grams of VOCs per liter of paint. While that is much lower than other paints, it is not the total volume of VOCs. Rather, it is the measure of VOCs in the base paint. Adding pigments for color may increase the total amount of VOCs. A typical light color pigment will increase the concentration by as little as 10 grams per liter. Darker pigments can increase the concentration by as much as 150 grams per liter.
To be considered a no VOC paint, the standards require that it must contain less than 5 grams of volatile compounds per liter. But again, this is just for the base paint. Like their low VOC counterparts, adding pigment can significantly increase the total quantity of VOCs in the paint.
Facility managers should note that low and no VOC paints are more expensive than conventional paint. A typical gallon of low VOC paint costs between 25 and 50 percent more than paints with higher levels of VOCs. Similarly, a gallon of no VOC paint can be as much as twice the cost of a gallon of standard paint. As more products are introduced into the market, the price differential between standard and low VOC paint has been decreasing. Also, as interest increases in low and no VOC paint, competition between manufacturers will further decrease the price differential.
It also can be more expensive to apply low and no VOC paint. The paints often do provide the same coverage as paint with higher levels of VOCs. As a result, two coats of low or no VOC paint may be required when a single coat of a higher VOC paint would have been sufficient.
Care must be exercised when cleaning surfaces coated with low and zero VOC paints. Maintenance staff should avoid using any ammonia based cleaning products, as they can permanently damage the paint surface. Here again, look for Greenguard and Green Seal certified paint. In addition to having to meet standards concerning VOC content, certified paints must meet minimum standards for abrasion resistance and washability.
James Piper, Ph.D., PE, is a writer and consultant who has more than 35 years of experience in facilities management. He is a contributing writer for Building Operating Management.
Green Seal GS-11
GS-11 establishes performance criteria for paints, and helps protect air quality, health, and
the environment by prohibiting harmful chemicals, limiting VOC content for base paint and colorants, and requiring consumer education measures regarding proper use, recycling, and disposal.
GREENGUARD Gold Certification
The GREENGUARD Gold Certification Standard includes health-based criteria for products like paints and also requires lower total volatile organic compound (VOC) emissions levels to ensure that products are acceptable for use in environments such as schools and healthcare facilities.