Do 3nine’s HEPA Filters Capture SARS-CoV-2 Particles?

During the pandemic, customers have contacted us wanting to know how effective our end filters are at capturing virus particles and whether there could be a risk that they pass through filters and thereby spread in facilities. We therefore contacted Patrik Oelander at Freudenberg Filtration Technologies SE & Co. KG, our supplier of our HEPA H13 filters, which are used in the final stage of the oil mist separation process. Freudenberg is a global technology leader in air and liquid filtration which 3nine has been working with for a long time, and who supplies our final-stage filters used on our oil mist eliminator. As 3nine’s technology achieves a high separation of small particles, the end filter has a long lifecycle, which enables us to use a high quality H13 class HEPA as a final-stage filtration. The filter we use is the standard in cleanroom environments and hospitals.

During the pandemic concerns of virus spreading in workshops has been a debated subject. One specific concern that has been raised was of how well Freudenberg’s filters are able to capture virus particles.

The HEPA H13 filters 3nine applies catch and store each and every particle – of which a virus is one – with an efficiency of at least 99.95%, with no matter of its size. This is, by definition, what is guaranteed by the quality standards related to the label of EN 1822 / ISO 29463 conformity

-Patrik Oelander, Freudenberg Filtration Technologies SE & Co. KG

With an estimated size of 0.1 µm, SARS-CoV-2 particles will be captured by the filter, which means that the exhaust air returned to the facility should be free from viruses or virus-carrying particles.

A lot of factors contribute to the spread of virus particles, however you can rest assured that they will indeed be captured by the HEPA filter. What we recommend, however – especially during the pandemic – is to air the facilities more often than usual. When replacing an air filter, it’s best to check with your employer what guidelines are used at the workplace and to carry out the filter change accordingly. You should also make sure to use protective clothing during the filter change. In order to minimise the risk of pathogen exposure, old and replaced filters should be packed airtight and disposed of properly.

-Patrik Oelander, Freudenberg Filtration Technologies SE & Co. KG

Even if the probability that air contaminated with virus particles reaches our oil mist separators is low, it is reassuring to know that the virus will be captured by the filters from Freudenbergs which we use. However, as a safety measure during the pandemic, it could be wise to replace the HEPA filter a bit more often than usual. Do you have questions or wish to order new HEPA-Filters, please fill our contact form.


Freudenberg FiltrationFreudenberg is known worldwide for its innovative technology and high quality. All of their HEPA filters have are certified accourding to SF13 and undergo an integrity test according to EN 1822:2009 prior to delivery.