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In today’s world where automation is highly advanced in the food industry, compressed air is widely used. For certain special processes in the food industry, compressed air may also come into direct contact with the products. In certain special chemical industrial areas, the air may already be polluted. If these pollutants come into contact with food without being separated first, they can undergo various physical and chemical reactions such as adsorption and absorption with the food, ultimately causing harm to consumers’ health and resulting in unnecessary losses for businesses. I. Correct understanding of compressed air: Based on the way products come into contact with compressed air, it can be classified into three types of contact: \"direct contact,\" \"indirect contact,\" and \"no contact.\" 1. Direct contact: This refers to the use of compressed air as part of the production and processing processes, including the packaging and transportation of safe food; the compressed air that comes into direct contact with the finished food or its ingredients is considered part of the production process. For example: when using air cooling and transferring the finished product from one process to another, compressed air should have the same quality priority as any other ingredient. 2. Indirect contact: refers to compressed air released into the general environment of food, including its packaging, processing equipment, and production facilities, as well as the storage areas for food and its ingredients. For example: using compressed air to blow-mold PET bottles or preparing and opening bags before pouring in food, similar to valves being activated by compressed air near the finished food or its ingredients. 3. Contactless: Food manufacturing companies often \"over-protect\" their air compression systems; therefore, it is equally important to focus on contactless, low-risk systems. Most factories have a significant proportion (over 50%) of compressed air used for “plant air” applications, which never come into contact with food or food packaging machinery. II. Regulations and standards are essential to ensure optimal food safety and reduce risks for consumers; it is important to comply with these requirements. International standards are very helpful in this regard. For example, ISO 8573-1:2010 specifies the key quality requirements for compressed air, and sets the maximum allowable levels of contaminants as well as the maximum particle sizes in each grade. To ensure that the quality of gas treatment in automated solutions meets standards and features high energy efficiency, parameter requirements for the quality levels of substances such as solid particles, moisture content, and total oil content are specified. https://pic3.zhimg.com/80/v2-bb81bdfbf6660cee04a9e0ce816490de_720w.jpg (1) Compressed air that comes into direct contact with dried foods such as grains and milk powder is used for conveying and mixing; it is also commonly utilized in food production. It will come into direct contact with food. Since these are dried foods, there are stricter requirements regarding air humidity. The compressed air quality classifications applicable to this situation according to the ISO 8573-1:2010 standard are as follows: – Solid particles: Grade 1 – Water: Grade 2 – Oil: Grade 1. Compressed air that comes into direct contact with non-dried foods such as beverages, meat, and vegetables is used for conveying and mixing; it is also commonly utilized in food production. It will come into direct contact with food. The compressed air quality classifications applicable to this situation according to the ISO 8573-1:2010 standard are as follows: – Solid particles: Grade 1 – Water: Grade 4 – Oil: Grade 1. The BRC/BCAS specifications for food-grade compressed air set the minimum purity and quality standards for compressed air used in the food and beverage industry. III. Selection of compressed air systems The food industry faces the challenge of choosing safe and effective compressed air systems. To make a sound decision, it is first necessary to determine how the company uses compressed air in its production processes. Regular risk assessment is also an effective means of monitoring whether compressed air poses a risk to food safety. Manufacturing enterprises need to pay close attention to the potential risks associated with compressed air pollution in food production. After conducting a preliminary risk assessment and classification of the use of compressed air, it is necessary to ensure, in accordance with industry standards, that the correct air quality is provided for each category and application, while also meeting the applicable air quality standards. Manufacturers can choose a variety of air compression and purification devices to minimize the risk of food contamination. Many companies are unaware of the contaminants and sources of contamination present in compressed air, thus ignoring it during hazard analysis. Hazards of compressed air: Biological hazards: 1 cubic meter of outdoor air can contain as many as 100,000,000 microorganisms. These microorganisms are drawn into the compressor and enter the compressed air system. If left uncontrolled, they will grow rapidly within this system. A pressure dew point above -26°C can inhibit the reproduction or growth of microorganisms, while refrigeration drying equipment with a pressure dew point of 3°C does not prevent microbial growth. To suppress such growth, control equipment with a pressure dew point of -40°C should be used. Chemical hazards: Since a large amount of lubricating oil is used in the production of compressed air, if not properly controlled, this oil can end up in contact with food and food additives along with the compressed air, and may even come into direct contact with the products themselves. Physical hazards: There are large amounts of dust particles in the air. Due to the properties of compressed air, its compression process causes these dust particles to gather, thereby contaminating foods or food additives through the compressed air. According to investigations, it is generally believed that there are two main sources of contamination in the new compressed air system: the air drawn into the system and the compressor itself. Traditional compressors often use oil for lubrication and cooling, and this oil may be carried downstream; if not treated, it will reach critical control points within the system. To avoid contamination by compressor oil, and to eliminate the main sources of pollution, most food and beverage companies employ air compression systems with \"oil-free\" compressor technology. In terms of risk analysis, food producers should consider the impacts of various potential risks, such as any failures in the internal sealing mechanisms or leaks of lubricants and oils. To obtain oil-free compressed air, it is possible to use oil-free compressors for this purpose (here, oil contamination in the environment is not taken into account; however, in cases where the surrounding environment is harsh and highly polluted, it is still necessary to remove oil from the compressed air after it has been generated). Oil-free compressed air can also be obtained by using appropriate oil removal devices at the later stages of the processing process.