NC Filtration Standard Capacity Particle Board HEPA 99.97% - 24" x 24" x 11.5"
DOE standard: Quality assurance inspection and testing of HEPA filters - UNT Digital Library
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PDF] Comparison Of HEPA/ULPA Filter Test Standards Between America And Europe | Semantic Scholar
air quality - EU EN standard 1822 vs US HEPA filters - Engineering Stack Exchange