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The California Building Standards Commission recently approved CALGreen, the nation’s first mandatory statewide green building code (see “Green Goes Mainstream in California,” In the News, 10/08). Scheduled to take effect on January 1, 2011, the new baseline standard calls for a 20 percent reduction in water use, improvements in energy efficiency and interior air quality, and the diversion of at least 50 percent of construction waste from landfills.

In addition, the new code includes two optional levels — CALGreen Tiers I and II — that can be adopted by jurisdictions wishing to require higher levels of performance. In areas where only the baseline code applies, builders can voluntarily comply with one of these higher tiers and receive certification for doing so from the local building department. Local jurisdictions retain the authority to write their own regulations, provided that the mandatory provisions of the new code are met.

Although environmental groups and certification organizations like the Sierra Club, the U.S. Green Building Council (USGBC), and Build It Green are generally supportive of the baseline requirements, they’ve expressed skepticism about the optional tiers. “The tiers cause confusion in the marketplace and the potential for builders to label their buildings green without substantiating their claims,” says USGBC Northern California Chapter director Elizabeth Echols. She also says that “many local officials who would be responsible for verifying builder claims do not have the technical expertise that LEED and other third-party verifiers provide.”

Mainstream builders’ organizations, on the other hand — such as the California Building Industry Association — argue that the tiered system will allow builders to meet a certifiable green standard without having to pay for expensive third-party verification. They also claim that many of the mandatory provisions are already part of the statewide building code, so building inspectors should have no trouble performing the necessary field inspections and enforcing the code. — D.F.

How Green Are Low-VOC Paints?

Some people like the smell of fresh paint, while others get headaches from it. The reason? VOCs, or volatile organic compounds, the same group of carbon-based compounds responsible for that “new car” smell. Oil-based paints are loaded with VOCs because they rely on petrochemical-based solvents as carriers for pigments, fillers, and binders. Latex paints use water as a solvent, but rely on VOC-based additives to improve various performance properties. Of course, the VOCs don’t remain in the paint; they evaporate into the air — most fairly quickly as the paint dries, but others more slowly as the paint film cures, making it hard for both painters and occupants to avoid exposure.

Many of the VOCs that can be found in a can of paint are harmless; others, like formaldehyde (used as a biocide) and benzene (used to speed up drying), are known irritants and probable carcinogens. Short-term exposure to VOCs can trigger allergic or asthmatic reactions, while long-term exposure has been linked to respiratory problems, kidney and liver damage, and memory loss.

The main reason VOCs are regulated, though, is that once they escape into the atmosphere, some of them react to sunlight and naturally occurring nitrogen oxides to form ground-level ozone, or smog. Paints and stains account for 9 percent of all VOC emissions in the U.S., second only to cars, according to the EPA.

A patchwork of regulations. The EPA first established VOC limits for architectural paints and coatings in 1999. Ever since, paint manufacturers have had to whittle away at VOC levels for both oil-based and latex-based paints to meet federal limits, which currently stand at 250 grams per liter (g/l) for flat paints and 380 g/l for nonflat paints. Today, an average can of flat interior latex paint contains about 150 grams per liter of VOCs, compared with as much as 380 g/l for the glossiest oil-based enamels.

Some states and regional agencies have adopted even tougher standards. For example, the Northeast Ozone Transportation Commission set a VOC limit of 100 g/l for flat paint and 150 g/l for nonflat paint — standards that EPA spokesperson Cathy Milbourn says her agency plans to match. Southern California’s Orange County, the smoggiest region in the U.S., has the strictest regulation, with VOC limits of 50 g/l for all coatings. This is also the typical upper VOC limit for most green-building standards, while the accepted level for so-called “no-VOC” paint is currently 5 g/l or less. Today, an average can of flat interior latex paint contains about 150 grams per liter of VOCs, compared with 50 g/l or less for a flat, low-VOC paint.

Better testing. But as manufacturers reduce VOC levels in their paints to meet these standards, the EPA’s tests are becoming increasingly irrelevant. That’s because Method 24, their nationally referenced VOC testing procedure, is virtually worthless for testing latex paints with VOC levels below 100 g/l, says Dane Jones, a coatings researcher at California Polytechnic State University in San Luis Obispo. “Method 24 is fairly accurate for solvent-based paints,” says Jones, “but with waterborne paints, it’s an indirect calculation that actually measures everything but the VOCs.” Since the expected margin of error on a 50 g/l paint can be 100 g/l, a paint could actually end up showing negative VOC levels, says Jones.