What you need to know about the eco-efficiency of paint
As the green building trend continues to grow, architects, designers and builders are striving to create environmentally responsible structures that provide healthy places to live and work. This trend has generated greater demand for green building materials and products with higher eco-efficiency. Green paints are often rated on the basis of their volatile organic compound (VOC) solvent contents, generally 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, we can see that paint is inherently eco-efficient. Paint not only improves the visual quality of our built environment but, more important, it protects and preserves the substrates to which it is applied. Consequently, less energy and material resources are needed to maintain, repair or replace structures and their components.
Exterior paint resists the damaging effects of wind, rain and sunlight, preventing the deterioration of wood, metal and masonry so that buildings last longer and require less maintenance. Painting the exterior with light colors can even keep a building cooler, reducing the amount of energy consumed by 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 drawback to using VOC content as an indicator of environmental acceptability is that it relates only to the amount, not the kind, of VOC in a product. Different VOCs have widely diverse properties, as well as various 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 and toxic air contaminant. Exposure to EG vapors may cause irritation to eyes, skin, nose, throat and lungs, and EG may provoke allergic reactions. 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 is done in occupied buildings or around people with odor sensitivities. It may be less important, however, when performance is a greater concern. The VOC solvents used in latex paints work together with resins (the “glue" that holds the paint together and sticks it onto the wall) to achieve better performance in various ways, such as better flow and leveling, touch-up, hardness, abrasion resistance and stain resistance.
Formulating any paint is a balancing act — and 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 paint, some limitations in performance might be necessary. While zero-VOC paint may be equal to conventional paints in some performance measures, it may be less in others.
For example, Dunn-Edwards zero-VOC Ecoshield Interior Flat Paint has excellent scrub-resistance, but provides less stain resistance and soil release than our standard premium interior flat, Suprema® Flat. Accordingly, we recommend Ecoshield primarily for interior surfaces that are not located in high-traffic areas subject to excessive wear and tear. When used in appropriate areas, however, the durability of Ecoshield approaches that of conventional latex paint. Newer technology has allowed us to produce ENSO®, a zero-VOC interior paint with performance comparable to premium latex paints, although at somewhat higher cost.
The best paint for any specific application is the one that best meets the performance requirements of the job, 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 used in manufacturing and distribution. At Dunn-Edwards, we're proud that, for decades, we have implemented best practices that reduce waste, avoid pollution and boost energy efficiency.
With a view toward continuous improvement, we invest heavily in research and development efforts to achieve even greater eco-efficiency in our products and we are constantly seeking new ways to be greener throughout our operations. Green is the color we choose to paint our world. Let us help you find your shade of green, too.