Contamination Control

• HEPA filters are tested and rated by their performance at retaining particles at the most penetrating particle size (MPPS) i. e. 99.95% for H13 HEPAs and 99.995% for H14 acc. to EN 1822.

• This means that HEPA filters will remove any solid or liquid particle from the air with an efficiency of at least 99.95 %

• Viruses like SARS-CoV-2 also often attach themselves to larger particles well within the focus of HEPA filters.

• HEPA filtration should be a key part of your infec­­tion control strategy if it’s appropriate to your building.

• they can provide additional air cleaning capabilities for buildings without any high efficiency filtration system
• Make sure to use high quality products with good filters. Low quality air cleaners can do more harm than good by creating a turbulent air flow while contributing little cleaning power
• dilution with fresh air should still be prioritized
• place the device as close as possible to your location, so you breathe the actual filtered air. The larger the distance to the AP, the higher the chance to inhale swirling contaminants which could include viruses.
• Activated carbon stage can remove hazardous gases released by cleaning agents (avoiding side effects from additional cleaning activity).

Reduce the risk of infection with professional HEPA filters and air purification systems

• increasing dilution with fresh outside air is most important
• use the same filter classes as generally recommended (e.g. at least ISO ePM1 50% with an ISO ePM10 pre-filter stage)
• maintain normal filter change intervals
• disable air re-circulation entirely or reduce it to a minimum
• if necessary increase fresh air dilution by frequently opening windows
• higher energy consumption should not be the main concern during these times

for healthcare and maintenance workers i.e. glasses, gloves, respirators, masks and clothing

move droplet nuclei out of breathing zones

In healthcare facilities, suspected or confirmed coronavirus patients should be placed in airborne infection isolation rooms with a negative pressure and appropriate HEPA or above filtration on the recirculation or exhaust air flows.

of contaminated air i. e. exhaust too close to HVAC air intakes

Check that all filters are operating effectively. And, when it’s time to change filters, take care not to release any viruses that have collected on the filter media into the internal environment – remembering that SARS-CoV-2 can survive for up to several days on surfaces. Dispose of any contaminated waste according to the guidelines in your location.

Tips for filter change (PDF)