APCD reduces wood coating emissions levels

The San Diego County Air Pollution Control District (APCD) approved changes to the APCD’s regulation on wood products coating operations which will lower the allowable emission contents.

The San Diego County Board of Supervisors acts as the APCD board, and the county supervisors voted 5-0 June 27 to approve the amendments for wood coatings and cleaning solvents. The amendments will not take effect for 12 months to allow affected businesses to deplete their inventories of non-compliant materials and transition to the new standards.

The rule regarding emissions from the coating of wood products and associated cleaning operations had previously last been revised in 2002. Current market availability of satisfactory coating and cleaning materials with lower volatile organic compound (VOC) content allowed for the amendments which regulate fillers, high-solid stains, multi-colored coatings, sealers, and low-solids coatings applied to new wood products.

The regulations do not affect refinish coatings such as those used to restore antiques or other existing wood products which had previously been coated and also do not affect residential non-commercial operations. The primary industries affected are cabinet, furniture, window, and door manufacturers.

The amendments also require surface preparation and equipment cleaning materials to comply with a VOC content limit of 25 grams per liter, and the small usage exemption limit for stationary sources was reduced from 500 gallons per 12 consecutive months to 20 gallons per 12 consecutive months. The amendments allow each operation to use up to 20 gallons per year of non-compliant coatings, which should address future situations where a coating with a higher emissions content might be preferred to achieve a desired finish.

The amendments also include updated definitions and record keeping requirements, and facilities using high-volume low-pressure spray must now have on-site pressure gauges available and in proper operation condition to measure the air cap pressure or handle air inlet pressure.

The new wood products VOC limits for clear topcoats were changed from 680 grams per liter (g/l) or 5.7 pounds per gallon (lb/gal) to 275 g/l or 2.3 lb/gal. The limit for fillers is reduced from 500 g/l or 4.2 lb/gal to 275 g/l or 2.3 lb/gal. The VOC emission limit for high-solids stains was decreased from 550 g/l or 4.6 lb/gal to 350 g/l or 2.9 lb/gal. Medium-density fiberboard coatings had been limited to 680 g/l or 5.7 lb/gal and are now restricted to 550 g/l or 4.6 lb/gal.

The reduction in multi-colored coatings is from 685 g/l or 5.7 lb/gal to 275 g/l or 2.3 lb/gal. Pigmented coatings had their emission limits reduced from 600 g/l or 5.0 lb/gal to 275 g/l or 2.3 lb/gal. The limit on sealers was reduced from 680 g/l or 5.7 lb/gal to 275 g/l or 2.3 lb/gal. The emissions standard for all other coatings had been 420 g/l or 3.5 lb/gal and is now 275 g/l or 2.3 lb/gal. Low-solids coatings, including toners and washcoats, had been limited to 480 g/l or 4.0 lb/gal and are now restricted to 120 g/l or 1.0 lb/gal.

The only changes to the standards for refinished wood products was a reduction in multi-colored coatings from 685 g/l to 680 g/l, although conversion varnish limits were added to that category and are restricted to 550 g/l or 4.6 lb/gal.

Surface preparation materials and application cleaning material had been limited to 200 grams or less of VOC per liter, but the new rules limit such materials to emissions of 25 g/l or less.

There are currently 125 permitted facilities in San Diego County which are subject to the amended APCD regulation. Those operations emit a combined VOC emissions total of approximately 157 tons per year. The changes are expected to reduce those emissions by approximately 19 tons a year, or 12 percent.

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