Volatile Organic Compounds (VOC) Explained
Solvents in paints, pastes and coatings are used to transfer them to the substrate they are being applied to. Once they do, the solvents are released into the atmosphere by evaporation. Solvents like varsol, mineral spirits, lacquer thinner, alcohol and methyl hydrate (to name a few) are actually 100% VOC’s because they are almost entirely released into the air as they dry.Until now, Canada has never had any rules governing VOC’s in paints or construction materials, only voluntary guidelines. That changes on September 9, 2010, when stringent limits for VOC laden materials will come into effect, with real penalties for transgressors.
Everything from adhesives, carpet glue, thermoplastic rubber coating and mastic, bituminous roof primer and coatings, to concrete curing compound and concrete surface retarders will be affected along with paint. But by far, the new VOC limits will affect architectural coatings the most. According to federal studies, paint and coatings account for 26% of all VOC emissions in Canada.
Most classes of paints will have their VOC’s cut by more than 50% from existing levels. Many producers are ahead of the curve with 0 VOC paints available since 2009 (several years behind the U.S). With the new regulations in place, most, if not all, manufacturers will put the maximum allowable VOC’s in each can of paint. That is why after Sept 9, 2010, you will see a warning on all solvent-based products advising not to add anything that might push the product past approved VOC levels-unless you want to break the law. Under the new rules, doing so is punishable by fines up to $10,000 per gallon.
The drive to eliminate VOC’s in construction materials and architectural coatings started twenty-five years ago in Southern California. A small group of concerned citizens complained about the toxicity of paints and other coatings. The complaints grew along with the environmental movement and now most consumers across North America expect safer paints.
Environment Canada has been suggesting VOC limits since 1990. By 2001, the federal government had quietly encouraged manufacturers to cut VOC’s in half. Then in 2006, the government decided to adopt the same VOC regulations that had already existed in most states in the U.S. Existing stockpiles of manufactured paint will have a two-year sell-through grace period, so September 2012 will be the deadline for the new limits. No old standard materials will be allowed to be imported or made in Canada as of this September 2010.
The Price Impact
Customers once dreaded the idea of paying more for low VOC paint, now they expect it. A year ago, zero and low VOC paints were prohibitively expensive, Today, zero and low VOC paints are priced competitively. In some cases, they are nearly the same price as high VOC paints. Until 2009, it was much more expensive to produce low and no VOC paints, so producers had to continue to make the common high VOC brands in Canada, for fear of losing market share. Green paint producers couldn’t compete but now a comprehensive standard is in place since 2010. Since everyone has to produce to the new standard, prices will still be competitive and not significantly higher than they are now.
The consumer doesn’t always know what a VOC is but they know it sounds bad and will be happy to use paint that is easier to live with during application. They care about their health but don’t always care if the paint is good for the environment. It just happens to be a happy by-product of using low VOC paint.
Resins, pigments, and proprietary additives create the film that becomes the dry paint. If latex paint only relied on evaporation, it would wipe off with a damp rag, no matter how long it was on the wall. Original latex paints had high VOC coalescence agents in order to make the paint more durable after drying. Glycol was also used as an antifreeze and agent for flow and leveling in latex paint. It has now been deliminated in the most high end, zero VOC paints. After this year, the only thing that can legally add VOC’s to paint is the colorants. Universal tinting systems are one of the biggest contributors of VOC’s since glycol is the suspension agent for the high ground color pigments. This enables the colorant to be added to latex or alkyd based paints. New tinting technology had to be created to eliminate VOC’s in the tinting process. Benjamin Moore, for example, introduced the Gennx tinting system in 2009, which uses an acrylic resin system instead of glycol to hold the colorant. Now only a tiny amount of VOC’s make it into the paint this way. An important selling point of the new paints for general contractors will be that the paint is LEED compliant and therefore can be used for generating rating points in your project. Green Seal certification standards say that if your paint contains less than 50 grams per liter, it is good for points toward your LEED standard.
How Painting Will Change
Zero or low VOC paint is going to force painters to change their application habits. In some ways it will be harder to apply and in other ways, easier.
Cutting And Rolling
With existing latex, one painter usually cuts in while another roll, so both applications dry and cure together. The zero VOC paints dry fast so, though painters can still cut and roll together, the roller can’t back-roll. If he does, the cut paint may be dry already and peel off with the roller. It is better to wait until the paint is dry to do a second coat. Fortunately, no VOC paints actually blend a bit better.
Whereas existing latex paints can handle a few freeze/that cycles, zero or low VOC latex paints can’t. If it freezes once, it is useless.
Painting Over Existing Finishes
Simply painting over high gloss oil paint won’t be possible anymore. Now you will have to sand the old paint thoroughly, wipe it down with thinner and prime over it with an oil primer or a latex to oil primer. Then you will have to use a 100% acrylic paint on top.
Alkyd and melamine paints will become a thing of the past. And no VOC compliant alkyd paint will be anywhere near as durable as existing alkyds. So say goodbye to your favorite alkyd paints. Producers will simply pull all their alkyds off the shelves.
The good news is that there is a water based alkyd on the drawing board but no release date is forthcoming from manufacturers.
Pool painters will not be able to use high VOC rubber film pool paint anymore after supplies run out. There will only be water based pool paint, or 100% solid epoxy finish, neither of which can be used to recoat existing painted pools. Pool painters will have to sandblast the old paint off then use epoxy or latex paints.
Faux Finish Follys
Imagine the fun faux finish painters are going to have once oil based glazes are no longer available. Oil glaze has a much longer open time than even the very best latex ones. New techniques are going to have to be developed to deal with the new reality.
Lacquer based paints have been the preferred way of finishing cabinets and furniture, but the VOC content in this, the highest VOC paint, will also be slashed, making drying times and applications much trickier until updated lacquer paints are made available.
Painting cement floors with alkyd paint with only 250 g of VOC’s per liter means that you have a choice. Use water based epoxy or 100% solid epoxy troweled on. Or you can use junk paint that won’t stay put because it won’t have the durability of older paints.