The SCAQMD's Rule 1113, already the nation's most stringent VOC regulation on architectural and industrial maintenance (AIM) coatings, presents even greater challenges following the revisions, with some of the new limits going into effect as soon as Jan. 1, 2005.

New VOC limits included in the latest round of reductions are 275 grams per liter (g/L) for varnishes and sanding sealers, 50 g/L for roof coatings, 100 g/L for stains, and 250 g/L for high-solids interior stains. In one concession to the industry, a previous 50 g/L limit for waterproofing sealers and waterproofing concrete and masonry sealers was revised upward to 100 g/L, with an effective date of July 1, 2006. The SCAQMD dropped a plan to enact various limits on different types of low-solids coatings, and retained the 120 g/L limit on "low-solids coatings."

Industry sources said the 275 g/L VOC limit on varnishes will effectively eliminate the use of solventborne varnishes. The NPCA also sought - unsuccessfully - revisions in the new VOC limits and effective dates for waterproofing sealers.

The revisions to Rule 1113 also include the elimination of the quart-container exemption from VOC limits for clear wood finishes, including varnishes, sanding sealers and lacquers, and for pigmented lacquers. Despite extensive lobbying by industry representatives for a delay in the effective date of the elimination of the exemption until 2008, the SCAQMD board approved an earlier effective date of July 1, 2006.

On a more positive note, at least in the view of some industry observers, was the SCAQMD board's indication that the district will investigate the possible development of a "reactivity-based" VOC rule for AIM coatings - a regulation that would take into account differences in the atmospheric reactivity of various solvents. Those differences are said to influence the ozone pollution-forming capability of various solvents and other volatile compounds.

Information on Rule 1113 is available from the district's website, located at www.aqmd.gov.