The Composites Fabricators Association would like to respond to the May 22 Plastics News editorial, "Fabricators must lead emissions reduction." The increase in styrene releases reported by industry, from 47,558,952 pounds in 1997 to 56,385,456 pounds in 1998, can be largely attributed to adoption of a new, more accurate method to estimate emissions for composites manufacturing operations. In February 1999, CFA met with EPA's Office of Pollution Prevention and Toxics, which manages the Toxics Release Inventory program, to explain that the new estimation techniques would likely result in an increase in reported emissions.
For many years, composite manufacturers used EPA's AP-42 emission factors to estimate emissions from open molding of composites. Most composite manufacturers and local regulators rely on emission factors to calculate emissions from these operations, since actual "stack tests" are difficult and expensive to perform.
Research conducted during the past few years, however, showed that the EPA AP-42 factors substantially underestimated emissions in many cases.
Using the newly available research data, CFA developed a new set of emission factors for open molding, called the Unified Emission Factors (UEF). Comparisons to carefully performed stack tests show that the UEF are very accurate for estimating emissions from open-molding operations.
Since the new factors are now available, EPA has withdrawn the old AP-42 factors for open molding, and is considering formal adoption of the UEF as the new official emission factors.
Meantime, EPA has suggested that composite manufacturers and local regulators employ the UEF to estimate emissions from open-molding operations. EPA has not withdrawn the AP-42 factors for nonopen-molding processes such as pultrusion and closed molding.
The current version of the UEF was released in April 1999 and may be obtained from this Web site: www.cfa-hq.org/reg-airemis sions.htm. This page also contains general information and guidance on emissions from composite manufacturing operations, EPA's AP-42 factors for nonopen-molding operations and pollution prevention technologies.
While reports of emissions have increased due to the switch to the more accurate emission factors, CFA believes that actual emissions have decreased, even though the industry is growing. This is because an increasing number of composites manufacturers now employ nonatomized resin application equipment, low-styrene resins, controlled spray, and other newly available pollution prevention technologies.