Airborne Surface Disinfection Testing

An automated airborne surface disinfection system (commonly known as fogging machine) diffuses a product in the gaseous state, by steam or compressed air from a device used with no humans present.

Used to disinfect, sanitise, or prevent the growth of mould, bacteria, and viruses, airborne automated disinfection system can sanitise large internal spaces, common touch surfaces and those areas that are difficult to access, effectively. This disinfection method is particularly applicable to environments that need to be kept sterile or where infective diseases can easily and quickly spread, such as hospitals, veterinary clinics, schools, public transport, and other public facilities.

The use of airborne surface disinfection methods requires efficacy validation in conformity to EN 17272. According to this standard, the airborne surface disinfection system is placed within an enclosed test chamber at a specified distance and location, and the active ingredient (e.g., ozone, hydrogen peroxide etc.) is injected the form of a gas, vapour and or aerosol. The process will be started remotely (with no people present) and it will disinfect the surfaces, and not the air, in the room. Results are expressed in logarithm scale to assess compliance to the standard. The method consists of two main parts that must be performed for each product and system.

Eurofins BioPharma Product Testing Italy offers a full panel of EN 17272 testing. We have already provided reliable testing according to the previously applicable standard (NF T 72-281), which enabled us to gain experience in the validation of such efficacies for many procedures. Our state-of-the-art laboratory is equipped for both whole rooms and small enclosure testing.

We are your one-stop-shop solution to cover efficacy claims on:

• Bactericidal
• Levurocidal
• Fungicidal
• Mycobactericidal
• Sporicidal
• Phagocidal
• Virucidal activity

In addition, special requests such as efficacy against C. difficile, MRSA, limited virucidal efficacy or efficacy against coronaviruses can also be covered from our testing capabilities.

Stainless steel carriers are inoculated with a suspension of microorganism and interfering substance (replicating clean or dirty conditions) in triplicate per each organism and left to dry. Two control carriers are prepared similarly and will be left outside the test chamber with similar environmental conditions.

Once dry, they will be moved inside the chamber and clamped vertically at 1-1.5m height facing away from the release source.

The airborne surface disinfection system is then placed within the test chamber at specified distances from the challenge (e.g., for a 65m³ chamber carriers are place 3.6m away from the system) and the disinfection cycle is started.

The chamber must be equilibrated for temperature (as standard 20 ± 1 °C) and relative humidity (50-70%) before starting the cycle.

The total airborne disinfection contact time (ADC) is recorded, starting from the first release of the product to the point where the carriers are retrieved or to the point where the deactivation (aeration) starts, if necessary.

The carriers are then processed in a recovery liquid and plated out onto appropriate agar plates. The results are counted, and the achieved efficacy expressed in LOG reduction.

The test follows the same methodology of the efficacy test with the aim of assessing the efficacy of the system throughout the chamber. For this reason, a total of 8 carriers are placed in the four corners of the room and specified heights and distances from wall/floor/ceiling. It is performed with only one organism, S. aureus, and must be passed to claim compliance with the EN 17272 standard.

Depending on the area and organism, different LOG reductions are required as detailed in the table below.