Published in the ECHO Journal, March 2010
Volatile organic compounds, or VOCs as they are commonly called, are an increasing concern in the paints and coatings industry. The continuing regulatory push toward even lower VOC content has prompted significant change in paint formulations, with paints and coatings manufacturers using low-solvent or solvent-free raw materials to create products that comply with the new regulations aimed at protecting the environment. In addition to higher regulatory pressure, there has been a surge in the green building movement, resulting in greater acceptance and awareness of low-VOC paints among consumers, many of whom are turning to these “eco-friendly” or “green” paints for the environmental benefits, as well as for health concerns.
Currently, there is no mandatory industry standard for what constitutes low- and zero-VOC paint. Even the voluntary standards that do exist, such as Leadership in Energy and Environmental Design (LEED), do not provide a clear definition and distinction between these terms. “Zero-VOC” and “no-VOC” are really misnomers and only mean extremely low VOC content levels. In fact, even regulators recognize that zero-VOC paints have a trace or residual amount of VOCs. What makes it more contentious is that EPA Test Method 24, the widely accepted method for determining VOCs, is inaccurate at VOC content levels below 100 g/L. At one paint manufacturer, a paint is termed “zero-VOC” if it contains none of the solvents that are added to conventional latex paints.
Since their evolution in the early 1990s, zero-VOC paints have been surrounded by a lot of hype. What began as a niche product that fit an emerging market trend has become the industry standard, with most paint manufacturers coming out with their own versions of zero- and low-VOC paint. In light of these explanations, a few questions still remain:
- Does a paint need to be zero-VOC to be considered green?
- Are all zero-VOC paints green?
- What really constitutes “green” paint?
With paint as the most visible aspect of a building, it is hard to imagine a green building that doesn’t use green coatings. Covering a large amount of exterior and interior surfaces of buildings, they make a substantial contribution to air quality. For paint and coating systems to be integral to the idea of green building, the focus should not solely rest on VOCs. Given that the primary function of paints and coatings is to protect and preserve the surfaces to which they are applied and, thus, extend the life of such surfaces, it is imperative for any green paint specification to address VOCs in the context of performance. The amount of VOC in paint, however, is only a small part of the product’s overall eco-efficiency.
Inadequate consideration of product performance when formulating low- to zero-VOC paints is counter to the goal of creating a more sustainable environment. 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.
In general, zero-VOC paints on the market today do not perform as well as paints with higher VOC content. The main appeal of zero-VOC paint is the lack of odor when it is used indoors. This characteristic can be important when painting must take place in occupied buildings or around sensitive people. It may be less important, however, in situations where performance is of greater concern. While technology for zero-VOC paints has improved and performance is beginning to approach that of standard paints, there are still trade-offs involved because one property may be enhanced at the expense of another.
To achieve the low-odor advantage of zero-VOC paints, some limitations in performance must be accepted. 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, including better flow and leveling, touch-up, hardness, abrasion resistance and stain resistance. When durability is more important than low odor, there are ultra-low-VOC paints that have VOC contents at or below 50 g/L. These are recommended for situations where long-term durability is more important than low-odor during application, drying and curing.
As sustainability has become a greater driving force in the design and construction of residential and non-residential buildings, manufacturers of quality paints remain committed to its efforts to ensure that their products are formulated for optimum performance, especially in terms of coverage and durability. They recognize that performance is the key to eco-efficiency of paint products, because optimum durability maximizes environmental benefits, while minimizing total burdens.
Ed Edrosa is the Specialty Coatings Product Manager at Dunn-Edwards Corporation, an ECHO member company.