Since the Clean Air Act became law in 1970, it has been used to regulate the content of volatile organic compounds (VOCs) in a variety of products and manufacturing processes, including architectural coatings. That section of the federal law initially focused on the release of VOCs into the outside air as ground-level ozone, a key contributor to smog. Today the popular focus for reducing VOCs in the built environment has turned inside, including the impact of house paints and other coatings on indoor air quality and the health and comfort of contractors, homeowners, and building occupants.
The Value of VOCs. VOCs in water- and oil-based paints are carbon-containing chemical compounds used as solvents to thin and bind the solid content and pigments, and as a coalescent to help the latex resins flow together toward the formation of the finished surface coat. The coating applies smoothly and evenly, hides brush strokes and the substrate being covered, and maintains a desirable durability, among other benefits.
The compounds readily and completely evaporate into the air as the coating is applied and cures, usually within a few days. Inside the home, in high concentrations and because they are often "trapped" within a structure, VOCs give off a distinct and lingering smell. Emissions also are slower to dissipate than in exterior applications, potentially affecting the eyes, nose, skin, and lungs of the painter and the occupants.
Improved Performance. Early attempts to reduce VOCs in paints focused primarily on the amount or ratio of solvent to solids and pigments in the mix. As a result, initial solutions dried faster (per the higher percentage of water and solids to solvent), covered less area, and were less durable to regular cleaning than their conventional counterparts.
Three decades later, low- and no-VOC formulas are nearly comparable in performance and price to their predecessors, thanks to advances in coating chemistry.
"In the past, contractors had to make a choice to pay more and sacrifice quality when using a low- or no-VOC coating," says Tom Dougherty, director of brand marketing for PPG, maker of Pittsburgh Paints (circle 111) and other brands. "Today, they don't have to make that choice, and paint professionals are hard pressed to notice much of a [performance] difference now."
That, and they've also adapted to low-VOC paints. "Contractors have learned to apply in smaller sections, to work faster, and not overwork the coating, and to apply it thicker," says Carl Minchew, director of color technology for Benjamin Moore (circle 112). "Most of them accept the trade-offs because of the lower odor."
Professional painters also learned to avoid darker colors among the early formulations. Deeper pigments, they say, were, and still may be, more difficult and costly to apply if the contractor or client demands a low- or no-VOC coating.
"Previous generations [of darker pigments with low VOCs] required four coats of a non-flat paint," says Henri Champagne, a painting contractor in Portland, Ore. "A third of my clients ask for lower VOCs, but they want a quality job first," requiring him to boost the cost of the job for the extra paint and labor, or seek new-generation coatings that solve the problem.
Cracking the code to create comparable performance to conventional coatings, though, doesn't come easily or cheaply. "There's been a fundamental change in the chemistry of paint," says Minchew. "It's been a huge, expensive undertaking that will be rolled out over several years," a process that has proliferated the mainstream paints during the past decade.
To amortize their investments in new formulations, manufacturers are applying the science to other types of coatings they offer. "It's allowed us to lower VOCs across several lines and business segments," says Dougherty.
Performance issues have proven to be a tougher nut among so-called natural coatings formulated with milk derivatives, clay, and other mineral-based ingredients. Veteran painting contractor Diane Call of Tucson, Ariz., has tried both milk-based and clay paints with varying success, but sees promising and ongoing improvements among a cottage industry of manufacturers.
"[Clay paints] tend to dry a shade lighter, so it's hard to judge the final color without a dry sample," she says, adding that daily surface cleaning, or "scrubability," also can be problematic.
Work to evolve the model continues, especially in pigment technology that enables deeper, richer colors without adding VOCs back to the coating. Among the big boys, Benjamin Moore, AFM, and PPG have set a higher bar with proprietary, non-VOC colorant systems for new brands of latex coatings, while Green Planet Paints, a clay-based coating maker in Patagonia, Ariz., is reformulating its product to address durability and enable a wider range of deeper colors.
Self-Regulation. Despite the efforts of the EPA (created to administer and enforce the Clean Air Act) and other related agencies, regulating VOCs in architectural coatings is a little like Major League Baseball doing tests for steroids but not human growth hormones. That's because VOCs are only one category among the toxic chemicals typically found in a can of paint, including those to improve flow, combat bacteria, and defoam the mix, among other benefits.
VOCs also can be added into the base formula after it leaves the factory–sometimes to above regulated levels–through standard color pigments and performance-enhancing supplements, all of which are mostly unchecked.
A paint's material safety data sheet (MSDS) is a good place to start. In addition to the formula's VOC content, use the MSDS to check the base paint's solids or pigment content (the higher the percentage, usually between 25% and 45%, the fewer VOCs), as well as a listing of other toxins (per EPA's definition) and possible health risks during application and storage.
Also, products registered with the EPA, OSHA, and the Transportation Department contain toxic chemicals that must be monitored by one or more of those agencies; products that are not registered are not required to be, given their lack of toxins.
As the architectural coatings industry continues to evolve in light of even tighter VOC-emissions standards (see "Regulatory Climate Change," page 51) and popular demand, builders also should maintain perspective on what is truly sustainable in terms of finishing the walls and ceilings of their new homes.
"Sustainability is also about durability and lasting performance," says Steve Revnew, director of marketing at Sherwin-Williams. "A coating that lasts five years instead of just one or two probably doesn't impact the environment all that much more."
Rich Binsacca is a contributing editor to ProSales. This article first appeared in the Spring 2008 issue of EcoHome, a sister publication.