High-Efficiency Particulate Air (HEPA) Filter 2 : A filter capable of trapping and retaining at least 99.97 percent of 0.3 micrometer monodispersed particles
Department of Energy AREA SDMP, DOE Handbook, Glossary of Environment Safety and Health Terms, DOE-HDBK-1188-2006, D.C. 20585, USA 2006. http://www.hse.niordc.ir/uploads/86_24_dictionary_ 2006.pdf, (Envir Hlth and Sfty - Amer) {44}