Driven by air quality regulations, architectural coatings, paints, and stains have been trending greener for almost 20 years. Developers seeking a price premium for projects certified through the U.S. Green Building Council’s LEED (Leadership in Energy and Environmental Design) point system have demanded low Volatile Organic Compounds (VOC) paints for a decade. Consumers concerned about indoor air quality are increasingly interested in zero-VOC paint.

Metro’s Recycled Paint Program has seen a noticeable drop in VOCs in paint in recent years. Metro collects leftover latex paint from consumers and blends it into MetroPaint. Testing across all colors of MetroPaint show the VOCs are dropping as the marketplace sells paint and stains with lower VOCs.

“Each year the feedstock of leftover paint we collect contains more low-and-no VOC paints, consequently the recycled product we make has lower VOC content. In fact over the past two years we have seen a 23% drop in the average VOC content of MetroPaint samples,” explains Jim Quinn, manager of the Metro Household Hazardous Waste Program.

What is a VOC?
The EPA definition of VOC is “…any organic compound that participates in a photochemical reaction, except those that have negligible photochemical reactivity.” VOCs are unstable compounds containing carbon and hydrogen that react in sunlight with nitrogen oxides in the air to create ground-level ozone or smog. These substances off-gas into the air.

Organic (volatile organic compounds) confuses some people, who think of organic food products.  However, organic to a chemist just means a compound containing carbon — and that includes everything that is or was living. With this definition, even petroleum and its products are organic.

Automobiles are the largest source of VOC emissions. Paints, stains, and architectural coatings are the second largest source. Paint can continue off-gassing long after it dries and the new paint smell is gone. One extensive 1999 study (Sparks et al.) estimated that less than half of the VOCs in applied paint are off-gassed in the first year. Some were found to be off-gassing five years after application. Studied compounds included common paint ingredients ethylene glycol, propylene glycol, Texanol, and butoxyenthanol.

Any organic compound that off-gases can be classified as a VOC, unless it is listed by the Environmental Protection Agency (EPA) as an “exempt compound.” Ammonia, acetone, PCBTF, methyl acetate, methylene chloride and volatile methyl siloxanes are solvents commonly used in paint that are exempt. In Europe, they are considered VOCs, but not by the EPA, whose definition is based solely on ability to produce smog.

Ethylene glycol and propylene glycol are not listed as exempt, so are listed as VOCs. Looking at these two chemicals, we see the flaw in using the EPA definition of VOC to gauge the health risk from using a particular paint. Ethylene glycol is basically antifreeze. It is used by some paint manufacturers to provide freeze-thaw resistance to paint and for the paint to dry slowly (keeping a wet-edge.) It is a VOC and is toxic to fish, animals, and people. Propylene glycol is also classified as a VOC. It yields freeze-thaw resistance and helps paint to keep a wet edge. Propylene glycol is used in food products and from a health perspective is relatively benign.

Testing Method
Often, zero does not mean zero. Consumer Reports magazine reported in its March 2009 issue that each paint they tested that claimed to have zero VOCs had some, though none was above government limits, which are set at 250 grams per liter (g/l) for flat paints and 380 g/l for others. The laboratory used EPA (testing) Method 24 and the differences between the manufacturers claims for the paint and laboratory findings could point to an inherent flaw in Method 24. Method 24 is a rudimentary test that was never established to measure VOC levels below 100 g/l. Although it is unreliable in measuring low levels of VOC it remains the only method that is recognized by the EPA.

The EPA will forward an amendment sometime after December 2009 that will call for a more accurate test method. The EPA is working to lower VOC limits to 150 g/l for nonflat paint and 100 g/l for flat.

Depending on the tinting system, tint can add significant VOC to the base. At this time the EPA is not contemplating a change from measuring the VOC of the base, to the level found in actual tinted paint that the consumer applies.

Toxic?
The EPA identifies indoor air to be three times more polluted than outdoor air. The EPA considers this one of the top five hazards to human health. And, while Consumer Reports magazine has advocated for the EPA to set a specific VOC standard for indoor air contamination based on public health and environmental risks, the EPA has no legal authority to regulate VOCs in the indoor environment. The EPA is currently establishing increased public education efforts so that consumers can gain an understanding of VOCs in the indoor environment. Currently, consumers have been using VOC numbers intended for the outside environment to get an indoor health perspective on paint.

Many consumers believe that if paint has zero VOCs or low-odor it is non-toxic, but most paints still have toxic ingredients such as biocides and fungicides. Zero VOC paints often contain ammonia, phthalates, heavy metals, toluene, and glycol esters.  These affect the heart, kidney and nervous system.

Harmful chemicals in paint can irritate the eyes, nose, throat, skin, and lungs. Many EPA-identified VOCs are carcinogenic and associated with lung diseases such as asthma, bronchitis, and emphysema. Higher concentrations experienced by professional painters and artists are known to lead to permanent respiratory, nervous system, liver, or kidney damage.

Green or Sustainable
Customers often confuse low odor paint for low VOC paint. Low odor paint often has chemicals added to mask the toxic fumes associated with fresh painting.

Consumer confusion is prevalent because there is no set rule or guideline to define “green” paint. Add the word “sustainable” to the equation, and customers are baffled by the number of products claiming to be better for the environment.

If we start from the premise that a coating protects a surface from decay, almost any coating can be called green. Many consumers consider a product as being green because it is produced locally, with renewable energy, using less water and natural resources. Others consider a product green because it has zero VOCs or low odor. A sustainable product would go beyond these definitions and be a product whose production, distribution, and use do not permanently deplete the materials used. A sustainable product would not create pollution or degrade habitat or land. A sustainable product would be packaged in a recyclable or re-useable container. Leftover product could be recycled, or re-used. A sustainable product would also deliver maximum performance so the product would not need early replacing.

Product development is starting to catch up with green performance. To produce a zero-VOC product, producers need to remove the coalescence solvents and glycol from the product. The elimination of these ingredients adversely affected the application and performance of early formulations. For example, when latex paint dries too quickly, film formation and thus durability is affected. The latex paint needs to flow evenly and smoothly and the binder needs time to fully coalesce. There was, and continues to be for many manufacturers, an issue with tinting zero-VOC bases. Universal tint systems contain solvents, and other tinting systems offer limited color choices.

Healthy Painting Tips

• All paint ingredients are toxic to someone.

• Dilute the fumes. Provide maximum (cross) fresh air circulation for several days and beyond if possible. Ceilings will take longer to ventilate because there is no air above the drying paint to dissipate the fumes. If the room below a loft is painted, be sure to ventilate the loft as well, because fumes will rise.

• Paint a bare room. Carpet, stuffed furniture, and drapes all absorb — then give off — pollutants.

• Read the product label and go online to check product literature and material safety data sheets. Avoid ingredients with EPA, OHSA, or DOT registration numbers because it shows the product has toxic ingredients that are being monitored. Substances listed as Hazardous Air Pollutants (HAP) should also be avoided.

Buy high-hide paint that will require fewer coats and put fewer chemicals into the air. Learn the solids content of the paint. Paint can have a solids concentration from 25% to 45% by volume. The more solids, the less volatile compounds to evaporate from the paint.

Paulette Rossi is an outreach specialist for MetroPaint, the first recycled paint program to earn the Green Seal certification.  For more information on MetroPaint, visit www.oregonmetro.gov/paint or call 503-234-3000.