Compliance with compressed air quality requirements in the food industry

Food manufacturers are required to follow HACCP principles to comply with legal requirements. Therefore, it is necessary to assess the risk level throughout the entire production and packaging cycle.

Often compressed air is not considered a potential contamination source, as it is regarded as an auxiliary medium. However, to fully comply with legal requirements, compressed air systems should also be included as critical control points in the HACCP checklist. Compressed air must meet the quality recommendations of ISO 8573-1 (see tables below).

ISO 8573-1 Quality Recommendations

Table 1. Compressed air purity classes according to ISO 8573-1.

Table 2. Compressed air quality recommendations.

Classification of Compressed Air in the Food Industry

Compressed air used in the food industry is divided into the following categories:

• Directly contacting food products (contacting);
• Air not contacting food products (non-contacting).
• If HACCP analysis identifies a potential risk that non-contacting compressed air may indirectly interact with food products or production areas, such air is classified as non-contacting, high risk.

More detailed category definitions are described below:

• Contacting: compressed air that comes into direct contact with ingredients and/or finished products, packaging materials, storage containers, or production/packaging equipment.
• Non-contacting: compressed air that does not interact with ingredients, finished products, packaging materials, storage containers, or production/packaging equipment.
• Non-contacting, high risk:compressed air, which is presumably not supposed to come into contact with ingredients, finished products, packaging materials, storage containers, or production/packaging equipment, but there is a possibility of contact (example: compressed air released into the surrounding atmosphere through a pneumatic cylinder may well come into contact with the product).

Depending on these categories, the level of air contamination must comply with ISO 8573-1 requirements, therefore it is necessary to control the following parameters:

• Amount of contaminants (particles): the requirements for the number of particles in compressed air are the same for all categories. The same level of filtration is required for each class.
• Residual moisture: the requirements for the amount of water vapor in the air are the same for the "contacting" and "non-contacting, high risk" categories. In this case, it is necessary to install an adsorption dryer that provides a dew point under pressure of -40°C or lower. This requirement is necessary to prevent the growth of microorganisms, since compressed air with a dew point of -26°C or lower inhibits bacterial reproduction. The compressed air purity requirements for the "non-contacting" category with a dew point of +3°C do not provide protection against microorganism growth (this dew point value is achieved using refrigerated dryers).
• Residual oil: the requirements for the total content of residual oil (in liquid, gaseous state, and as oil mist) are the same for all categories. The same level of compressed air purification is required for each class.

Izmerkon company offers various solutions from the CS Instruments brand for controlling the most important measurement parameters such as dew point, as well as particle and residual oil content in compressed air. With CS Instruments measuring devices, both continuous monitoring and mobile measurements are possible.