Over the past decade, cartridge-style dust collectors have overtaken baghouses as the preferred technology for industrial dust collection. Combining high-efficiency filtration with compact size and reduced pressure drop, a high-efficiency cartridge dust collector will usually be the system of choice.
Environmental and safety personnel today must deal with an increasingly complex alphabet soup of regulations as the EPA, OSHA and other organizations continue to tighten air quality and safety requirements. Meeting these requirements should be first and foremost in any dust collection game plan. The following FAQ addresses the most important safety considerations when making an informed dust collection decision.
OSHA has established permissible exposure limits (PEL) for hundreds of dusts ranging from nonspecific or “nuisance” dust to highly toxic substances. These limits are based on an 8-hour time-weighted average (TWA) exposure. Further information on PELs can be found at www.osha.gov/SLTC/pel/.
One area of concern involves stricter limits on exposure to hexavalent chromium, a known carcinogen. OSHA has set thresholds as low as 5 micrograms (0.005 milligram) per cubic meter TWA. This is 10 times stricter than the limits for some other toxic dusts. Dust collectors need to be equipped with very high efficiency filtration media to meet such requirements.
How do you know if your dust collector complies with emission thresholds? The equipment supplier should provide a written guarantee stating the maximum emissions rate for the equipment over an 8-hour TWA. Filter efficiency stated as a percentage is not an acceptable substitute, even if the supplier promises 99.9 percent efficiency.