Why compressed air quality needs more attention

If it is not sprayed directly into the product for aeration, used to apply glaze, for example, or applied to spray off food products, it at least serves to transport products, blow open packages or clean surfaces. This is another way compressed air eventually comes into contact with food products. And that's not nearly as innocent as it seems. Even when you follow hygiene standards.

Text Elise Noyez |  Image BEKO TECHNOLOGIES

The basic principle of compressed air is simple: air is extracted from the environment and compressed using a compressor. However, this also means that all contaminants and bacteria present in the air drawn in - and there can be quite a few - are concentrated in the compressed air. What is relatively harmless under normal conditions can be compressed to sometimes problematic concentrations. If this then ends up on or in the foodstuffs, there is a risk of contamination.

Three risk factors

Compressed air treatment aims to reduce the risk of contamination. To this end, it generally targets the three main risk factors for bacterial growth and development: moisture, dust and oil. In other words, the use of dryers, filters and activated carbon filtration forms the basis of compressed air treatment. Crucially, however, there are considerable gradations in these. While conventional refrigeration dryers limit the moisture content of compressed air to 6 g/m³, membrane dryers and adsorption dryers, with residual moisture values of 0.4 g/m³ and 0.1 g/m³, respectively, achieve significantly better performances. Not insignificantly, incidentally, the above compressed air treatment never completely removes bacteria from the compressed air. Only a catalyst is capable of doing so.

Between regulation and reputation

To shape compressed air treatment, food companies rely primarily on the various hygiene norms and standards. After all, BRC8, FSSC220000 and IFS, among others, contain provisions on this subject. That should suffice, right? Unfortunately. In reality, most standards are vague and inadequate. They do mention the need for compressed air treatment and quality control, but concrete regulations on the method of filtration, drying and control, or the quality parameters to be achieved are lacking. As a result, in practice, systems where compressed air quality is substandard (or at least unknown) are approved on an almost daily basis. This can eventually sour food companies. After all, contamination will not be noticed in the production line, but when problems occur in the field, infections can be traced back to the compressed air. In the process, they will face not only the costs associated with locating and fixing the source, but also a huge reputational cost. A good reason to invest in optimal and traceable compressed air quality.

Traceable, across the board

Compressed air treatment specialist BEKO TECHNOLOGIES consistently bases its activities on parameters and classifications according to ISO 8573-1:2010. On the basis of the size and quantity of particles, moisture content and oil content in the compressed air, various quality classes are defined therein. For compressed air that comes into direct contact with food products, BEKO TECHNOLOGIES recommends the highest quality class regarding particles and oil content, and the second highest class regarding moisture content. To this end, it can assemble complete treatment systems itself, upgrade an existing installation or provide advice. However, all this is only possible if the compressed air quality is also effectively known. In addition to air quality audits, regular or preferably continuous measurement of dust, dew point and oil vapor is therefore recommended. In this way, effective compressed air quality can be ascertained at any time and the production process becomes traceable. The prerequisite for a safe product.