Room for a View

BY ROBERT WENDOLL

Beyond VOCs: What You Need to Know about the Eco-efficiency of Paint

As the green building trend grows, design professionals are striving to create environmentally responsible structures that are healthy places to live and work. This has generated greater demand for green building materials and products with higher eco-efficiency.

Paint specification is an important project component. The U.S. Green Building Council's LEED Green Building Rating System awards one point for the use of low-emitting interior paints to improve indoor air quality. The LEED system indicates allowable VOC (volatile organic compound) solvent contents for different categories of interior paint and coatings. VOC content is measured as grams of VOC per liter of coating.

The amount of VOC in paint, however, is only a small part of the product's overall eco-efficiency. When we look at the bigger picture — understanding eco-efficiency as the ability to satisfy human needs in ways that minimize adverse impacts on energy and material resources, environmental quality, and human health and safety — we can see that paint is inherently eco-efficient.

Paint not only improves the visual quality of our built environment but, more important, it also protects and preserves the architectural substrates to which it is applied. Consequently, less resources are needed to maintain, repair or replace structures and their components.

Exterior paint resists damaging effects of wind, rain and sunlight, preventing deterioration of wood, metal and masonry, so buildings last longer and require less maintenance. Painting the exterior with light colors can keep a building cooler, reducing consumption of energy for air conditioning. Interior paint resists soiling, staining, wear and surface abrasion, which helps keep homes and workplaces clean and sanitary, without excessive use of detergents and water.

The key to eco-efficiency of paint involves both what is in the paint, to achieve optimum performance, and what is not in the paint, to avoid adverse impacts on the environment and human health and safety. One of the drawbacks to using VOC content as an indicator of environmental acceptability is that it relates only to the amount, and not the kind, of VOC in a product. Different VOCs have widely different properties, and different environmental and health effects.

For example, most paint manufacturers use ethylene glycol (EG) as a solvent in waterborne "latex" paints, even though EG is listed as a hazardous air pollutant. More than 25 years ago, Dunn-Edwards removed EG from all its products and substituted a non-toxic alternative, propylene glycol.

Given the concerns about certain VOCs, why aren't all paints zero-VOC? Different paints are made for different purposes. The main appeal of zero-VOC paint is the lack of odor when used indoors. This characteristic can be important when painting must take place in occupied buildings or around sensitive persons. It may be less important, however, in situations where performance is a greater concern. The VOC solvents used in latex paints are functional ingredients that work with resins (the "glue" that holds the paint together and sticks it onto the wall) to achieve better performance in various ways — for example, better flow and leveling, touch-up, hardness, abrasion resistance and stain resistance.

Formulating any paint is a balancing act. Trade-offs are generally involved, as one property may be enhanced at the expense of another property. To achieve the low-odor advantage of zero-VOC paints, some limitations in performance must be accepted. While zero-VOC paints may be equal to conventional paints in some performance measures, they are less effective in others. For example, our Ecoshield Interior Flat Paint has excellent scrub resistance, but it has less stain resistance and soil release than our standard premium interior flat, Decovel. Accordingly, we recommend Ecoshield primarily for interior surfaces that are not located in high-traffic areas. When used in appropriate areas, however, the durability of Ecoshield approaches that of conventional paints.

The best paint for any specific application is one that meets performance requirements of the situation with the least potential for adverse impacts. That is eco-efficiency in a nutshell. But eco-efficiency also extends beyond the product, to the processes that are used to manufacture and distribute the product. Dunn-Edwards has implemented best practices that reduce waste and boost energy efficiency.

This includes everything from recycling production tank washwater as feedstock for the next batch of paint, to installing advanced dust collectors that capture pigment dust and return it to the production process immediately. Our system of off-hours distribution from warehouse to stores reduces traffic congestion and air pollution, while our store delivery service direct to customers eliminates as many as 10,000 consumer trips daily in our marketing region.

With a view to continuous improvement, we invest heavily in research and development to achieve greater eco-efficiency in our products, and we are constantly seeking ways to be greener in our operations. Green is the color we choose to paint our world.

Robert Wendoll is environmental affairs director for Dunn-Edwards Corporation.