Covid-19: Frequently asked questions

What barrier against corona virus’ spread is included in Serres suction bags?

During liquid collection and before the suction bag gets full, air contained in the bag and flowing towards the vacuum source is filtered through the hydrophobic filter.

Serres suction bag with backflow valve

The bacteria filtration efficiency (BFE) of the hydrophobic filter is on average 99,97%.

(Staphylococcus aureus, ASTM F2101, Nelson Laboratories, LLC)

>99,9% of particles size 0,4μm or greater are filtered from the air (independently tested by VTT Finland, data available on request)

It means that the hydrophobic filter included in each suction bag does not filtrate particles as small as viruses with enough efficiency. In order to stop coronavirus (whose diameter seems to be around 0,12 μm according to Wikipedia) to move towards the vacuum source, the use of an additional viral filter on the vacuum tube is highly recommended (see next question).

When the suction bag becomes full, the hydrophobic filter gets wet and it will block liquids from entering the vacuum source and totally shut off any airflow and potential spread of viruses.

What is the additional viral filter?

Serres offers a viral filter (ref 57702) to be connected between the Serres suction canister and the vacuum source to protect the vacuum source from being contaminated by viruses.

Our advice to healthcare professionals facing shortage of viral filters is to reserve their use in connection with portable or stand-alone electrical suction pumps; as in the case of central vacuum or compressed air systems, potentially contaminated air is removed from the point of care.


The package contains 10 pcs of individually packed products.

The bacterial efficiency of the viral filter is min. 99,999% (Staphylococcus aureus, ASTM F2101-7, Lab 846021-S01)

The viral efficiency is min. 99,999% (Bacteriophage, ASTM F2101-7, Lab 846021-S01)


The viral filter is manufactured by GVS whose has given following further information:

We have not specifically validated our filters for removal of the COVID-2019, MERS-CoV and SARS-CoV. However GVS’ HMEF and HEPA filters are tested at Nelson Laboratories passing BFE (Bacterial Filtration Efficiency) and VFE (Viral Filtration Efficiency) test using Staphylococcus Aureus (*ATCC #6538) and bacteriophage PHI X174 (*Dimension about 0.025) resulting an effective barrier against bacteria and viruses (documents available on request).

Numerous of these reports have shown that GVS HMEF and HEPA filters serve as a complete barrier to contaminated body fluids and have been validated for removal of a range of clinically relevant bacteria and viruses, including, but not limited to Influenza A virus (H1N1: 0.08-0.12), HIV (0.08), Hepatitis C virus (0.8), Adenovirus (0.07), Cytomegalovirus (0.1), Orthmyxovirus (0.12) and Mycobacterium tuberculosis (1.0). COVID-2019, MERS-CoV and SARS-CoV are Coronavirus species and its size ranges from 0.06 to 0.2. Therefore, we believe that our filters may prevent those viruses.

What other protection is available in the Serres suction bag system?

The vacuum source protector (ref 6001114) prevents liquids entering the vacuum source in case of a faulty leakage from the suction bag due to an installation error.

Connect the vacuum source protector between the suction canister and the vacuum source. The vacuum source protector is replaced in every 30 days. The package contains 15 pcs of products.

Serres Vacuum Source Protector

What is the disposal and cleaning procedure for the Serres suction bag system during the COVID-19 pandemic?

When a suction bag needs to be replaced, we recommend the following procedure to ensure that air contained in the bag does not come out.

  • Close the patient port with the plug
  • Stop vacuum
  • Remove the bag from the canister
  • Turn the bag upside down to wet the hydrophobic filter and totally shut off airflow


Please watch this video showing the safe disposal procedure.


In addition, we recommend you disinfect suction canisters and vacuum tubes between patients.