Is HEPA filters of 99.99%@0.3um Sufficient for Biohazard materials?

HEPA filters used for laminar or biohazard are IEST RP Type C which is >99.99%@0.3um in accordance to IEST RP standards and also used in conjuction with US military specs. For usage of HEPA filters,. Biosafety and animal labs, hospital ventilation design and NSF49 are used in reference or conjuction to it.

 

Rational:

HEPA filters used in laminar air flow or biosafety, chemical safety are >99.99%@0.3um, for nuclear is Type B >99.97%@0.3um. Using higher filtration efficiencies or even ULPA filtration will not see any benefit but possibly decrease air change or volume increasing unncessary filter loading and drastic decrease in filter lifespan.

Why do filtration specialists or we say it is more than sufficient?

Filtration Efficiency also increases when particle size decrease as the electrostatic filtration will greatly increase. The most penetrating particle size (MPPS) is actually around 0.1-0.2um.

Viruses is much smaller than 0.3um, about 0.001 to 0.5um and viruses and Pathologens require nutrients and colonies to form and multiply. 

Spores are very resisilent but they are much bigger and easily filtered, the growth is transported from oustide.

Thus there will be near zero count of viruses of pathologens that will possibly fly through and no nutrients, so it is zero chance it will grow.

 

*Facilities with HEPA systems and biological safety cabinets should leave systems on for 24hours to ensure air integrity of cleanrooms or laboratories.