What is HEPA?
High-efficiency particulate absorption or HEPA is a type of air filter. Filters meeting the HEPA standard have many applications, including use in medical facilities, automobiles, aircraft, and homes. The filter must satisfy certain standards of efficiency such as those set by the United States Department of Energy (DOE). To qualify as HEPA by US government standards, an air filter must remove (from the air that passes through) 99.97% of particles that have a size of 0.3 µm or larger. A filter that is qualified as HEPA is also subject to interior classifications.
Grinding concrete equipment can produce large amounts of airborne crystalline silica. Inhalation of crystalline silica can lead to chronic or accelerated silicosis. Chronic silicosis, the most common form of the disease, usually occurs after 10 or more years of overexposure. As silicosis progresses, symptoms appear such as severe cough and shortness of breath following physical exertion. Without adequate dust controls, construction workers may develop accelerated silicosis, which results from very high silica exposures and develops over a period of only 5-10 years.
Always use HEPA rated Dust Extractors, filters, fans, and other equipment to maintain negative pressure in the construction area and clean air in occupied areas. You may also want to consider using wall-mounted magnehelic gauges to monitor air-pressure differentials.
The keys to preventing silicosis are to minimize the amount of silica-containing dust in the air and to avoid breathing silica-containing dust. There is no cure for the disease once it develops, but it is 100 percent preventable if employers and workers work together to minimize exposures.