Microbiology laboratory 5 Microbiological tests on air purifiers and filters

Testing the efficacy of air treatment systems against microorganisms

Validating the efficacy of your air purification systems and providing scientific proof of your solution to clients and end-users.


Why treat the microbiological quality of air?

Causing over 40,000 premature deaths per year in France  according to French public health resources, the quality of air is a public health issue. Environments inside can be more polluted compared to those outside due in part to an accumulation of chemical or microbiological air-borne pollutants, a phenomenon potentially linked to a lack of air-renewal within a system or airing of enclosed spaces.  

In certain enclosed environments, it is not always possible or desirable to open the window due to outside pollution, controlled atmospheric conditions inside -clean rooms, etc. On the other hand it is also possible that the inside environment is too polluted to envisage airing, necessitating a “cleaning” of the enclosed air.  

Causes for reduced microbiological quality of the air indoors include:

  • Presence of mold on the walls or surfaces, following water damage and/or penetration or at a thermal bridge
  • Dirty air-treatment system, or one ill-adapted to the usage within a particular building.
  • Occupancy load exceeding building design, lack of air renewal in a meeting room…..

Should individuals present in a room experience signs of discomfort, an air quality control assessment could prove useful.  Use of equipment to improve the microbiological quality of air could provide a punctual or long-lasting solution.

The various air-treatment methods

Each system aims to block or destroy the microorganisms in the air in order to reduce the level of biological pollutants and thereby improve the indoor air quality within the building. 

Each method has its advantages and disadvantages: in order to determine the process best adapted to your activity and premises, a preliminary study is necessary.


The filtration medium acts as a barrier blocking unwanted particles by porosity or electrostaticity.


A physiochemical reaction, amplified by the presence of titanium oxides (TiO2), that uses light and in particular UV to destroy the pollutants including bacteria, viruses and mold within the medium.


This technology emits negative ions into the air leading to air-borne particles becoming charged via electrostatic attraction. The charged particles then sediment out of the air resulting in its purification of microorganisms.


Ozone at high concentrations acts as a biocide destroying or inactivating microorganisms.

Essential oil diffuser

Certain essential oils have a biocidal action on bacteria, viruses or mold.

Innovative solutions

For industries having developed a new technology to improve indoor air quality, we can test and validate the efficacy of their solution on microorganisms.

Filtration unit installation

Air treatment units can be installed according to their specificity in different locations:

  • Office
  • Shopping center
  • Cinema
  • Theater
  • Museum
  • Food industry
  • Factory
  • Residential building
  • Airport
  • Train station
  • Operating room
  • Cleanroom
  • Hospital
  • Other public location

Each work environment and public area has its own specific requirements and a preliminary study is necessary based on which we advise the air-treatment systems best adapted to your needs.

Salle de réunion

Air polluting microorganisms that can be treated by such air purification systems

Depending on the equipment characteristics, a large panel of microorganisms and allergens can be blocked or destroyed:

  • Bacteria
  • Mold
  • Virus
  • Cat allergens
  • Pollen

Air quality improvement

Ventilation systems

Ventilation systems allow a renewal of air and thereby improve the quality of air indoors by bringing in new air from outside. To complete this approach, it is possible to add air treatment systems:

Mobile units

Mobile units are generally the same size as an air conditioner on wheels but can be more compact (on a desk) or voluminous to meet the needs of large industrial spaces. These units function completely independently: sucked up air is treated and reinjected into the same room.

Integrated units

These are added to the air handling units of office blocks, public buildings and industries in order to treat new and/or recycled air. Different methods of air treatment exist.

Testing facilities for evaluating equipment performance 

Numerous air decontamination equipment are introduced to the market each year.

In order to prove the efficacy of a product against microorganisms and compare it against other competing products, a scientific evaluation is one gage of quality.

At Conidia Coniphy, we have developed testing facilities allowing the qualification of all types of equipment.

Validation of airstream filtration

This innovative tool developed in-house in collaboration with partners in the car industry measures the quality of cabin air filters (pollen filters) and demonstrates their efficacy in filtering out microorganisms. Further development of this equipment has enabled the testing of numerous filters in other lines of business.

Validation of filter fabrics and masks

The Covid-19 pandemic emphasized the need to validate surgical masks and all filter fabrics in France according to current regulatory standards, NF EN 14683. In addition to the standardized method, we can adapt the protocol to meet with your specific needs when testing the efficacy of your media at filtering out microorganisms (bacteria and mold).

Evaluation of air purifiers in test chambers

Our 1m3 and 20m3 test chambers allow the demonstration of a reduction (percentage or logarithmic) in the concentration of microorganisms in the air. The choice or microorganisms is varied according to the requirement of the field of study. This enables the evaluation of equipment in controlled conditions.

In-field testing

Laboratory testing allows the assessment of air-treatment equipment in controlled conditions and thus provides data on efficacy in standard conditions. Using such standard protocols facilitates the comparison of different equipment.

The in-field use of the air-treatment systems can lead to different results. Evaluation of the performance of the equipment in situ allows the evaluation of its efficacy for a particular activity within a particular environment. This control step permits the validation of equipment choice to meet specific client needs.

Our solutions associated with microbiological tests on air purifiers and filters

Microbiological analysis of air


Testing the resistance of materials to microorganisms

Let's work together !

If you have any needs or questions about environmental microbiology, contact us and we'll provide you with the answers you need.