Technical hygiene
You can order the sampling materials for ventilation and air-conditioning systems from us and have the analysis carried out in an accredited laboratory in accordance with VDI 6022. You will receive a test report containing the results in accordance with VDI 6022.022.
Order sampling materials
Once you have successfully completed a training course in accordance with VDI 6022 Type A/B, you will be able to take samples as part of hygiene inspections. You can obtain the samples required for these services from us and have them analysed in accordance with the relevant standards in our accredited laboratory. We will then provide you with a test report containing the test results and an assessment in accordance with VDI 6022.
Request our free one-off trial kit now – ideal for new customers to familiarise themselves with the process and how to use it.
The test kit contains a surface sample, a sampling log and instructions on how to take samples. It is intended exclusively for new customers and is designed to give you a no-obligation introduction to our sampling service.
Simply tick the relevant box on the order form.
As part of a hygiene inspection, a surface survey must be carried out at representative sampling points to reflect the current state of hygiene of the plant components. Surface samples can be used to document the effectiveness of maintenance and cleaning as part of a hygiene inspection.
In accordance with current guidelines, Rodac agar plates with an area of 25 cm² are prescribed for qualified surface sampling. The test results are categorised and assigned to corresponding recommendations for action. When sampling uneven or sensitive surfaces (e.g. heat exchangers), swab or smear samples must be used. Swab samples are evaluated on a qualitative basis only.
The new edition of VDI Guideline 6022 Part 1 on the hygiene of ventilation systems and air-conditioning units has been in force since the beginning of 2018. In the video, we demonstrate how to take surface samples using RODAC plates in accordance with the new VDI 6022 Part 1 for laboratory analysis by TÜV NORD.
In accordance with VDI Guideline 6022, an air sampling procedure must be carried out as part of a hygiene inspection to determine the microbiological contamination of the supply air in comparison with the intake air (reference air). The requirement of the guideline is met if the microbial count in the supply air is no higher than that in the reference air. To minimise the influence of ambient air on the supply air measurement, it is recommended that the measuring instrument be positioned in the immediate vicinity of the supply air outlet. Careful selection of the reference air is crucial for the accuracy of the results. At each sampling point, one culture medium for the detection of bacteria and one culture medium for the detection of fungi are used.
Please note that we need to allow approximately two weeks’ lead time for the issue of the air sampler by TÜV NORD. You have the option of ordering the air sampler for delivery (express delivery charges apply) or collecting it in person.
As part of hygiene inspections in accordance with VDI 6022, airborne micro-organism measurements must be carried out using the MAS 100 air sampler. The operation of our MAS 100 hire units and the handling of the culture media are demonstrated in the following video.
In order to be authorised to work on ventilation and air-conditioning systems and to take samples during maintenance or cleaning work, you require hygiene training in accordance with VDI 6022 Type B.
To be able to take samples as part of regular hygiene inspections, you require hygiene training in accordance with VDI 6022 Type A. Both training courses are offered by the TÜV NORD Academy.
Water samples in accordance with VDI 6022 in the vicinity of air-handling units may be taken by personnel who have completed the VDI 6022 Type B training course. Hygiene inspections of decentralised humidification units (VDI 6022 Sheet 6) may also be carried out by personnel who have completed the hygiene training course in accordance with VDI 6022 Category WKT (maintenance and inspection of air humidifiers).
Once the laboratory has prepared the sample, it has a limited shelf life. It should therefore be returned to the laboratory within two weeks. The maximum shelf life of an unopened pack under optimal conditions is stated by the manufacturer on the culture media.
How to store the sample material correctly until sampling: