What is the national standard for compressed air used in food processing?

I. Current Status of the Standard System for Compressed Air Used in Food Processing

In food processing, compressed air is commonly used for material conveying, mixing, cooling, packaging, and powering pneumatic equipment. Because compressed air may come into direct contact with food or food-contact surfaces, its quality directly impacts food safety. At present, China does not have a single, dedicated mandatory national standard specifically for “food-grade compressed air”; instead, it relies on…Basic Standards for Food SafetyandCompressed Air Quality StandardsImplement integrated management through a combined approach.

II. Analysis of Core Reference Standards

When establishing testing standards for food-grade compressed air, enterprises primarily refer to the following two types of standard systems:

• Food Safety and Hygiene Standards:For example, the “National Food Safety Standard: General Hygiene Specification for Food Production” (GB 14881). This standard explicitly stipulates that when compressed air or other gases may come into contact with food or food-contact surfaces, they must undergo purification treatment to ensure compliance with applicable hygiene requirements and prevent contamination of the food.
• Compressed Air Quality Standards:As in “Compressed Air – Part 1: Contaminant Purification Classes” (GB/T 13277) or international standards ISO 8573 series. These standards impose stringent classification levels for contaminants such as solid particles, moisture, and oil content in compressed air; the food industry typically requires attainment of higher purification grades.

III. Key Testing Indicators

According to the aforementioned standard system, routine testing and periodic verification of compressed air used in food processing primarily focus on the following key indicators:

• Oil content:This includes the total oil content (oil vapor, liquid oil, and aerosols). Compressed air used in food processing typically must meet oil-free or ultra-low-oil‑content standards to prevent lipid contamination of food.
• Moisture (Pressure Dew Point):Excessive moisture can cause pipe corrosion and microbial growth. Measuring the pressure dew point allows you to assess the dryness of compressed air; food‑grade applications typically require a lower pressure dew point.
• Particulate matter:Detect the particle size and concentration of airborne particulate matter and impurities to ensure that the particulate matter level meets food-contact requirements.
• Microbiological indicators:These include total bacterial count, molds, yeasts, and specific pathogenic bacteria. This is the key parameter that distinguishes food-grade compressed air from ordinary industrial compressed air, and it is typically assessed by sampling and culturing using either the impact method or the filtration method.

IV. Recommendations for Corporate Compliance and Governance

To ensure that compressed air used in food production consistently meets safety requirements, enterprises should establish a comprehensive control and management system:

• Configure an efficient filtration system:Properly install water‑removal, oil‑removal, dust‑removal, and microbial‑filtration units downstream of the air compressor, and replace the filter elements on a regular schedule.
• Develop a testing plan:Based on the risk assessment of the manufacturing process, the testing frequency for each parameter shall be determined. Critical parameters such as microbial counts and oil content should have their testing frequency increased.
• Enhance Record-Keeping and Traceability:Maintain detailed records of the compressed air system’s operating parameters, maintenance activities, and inspection reports to ensure effective traceability in the event of audits or quality fluctuations.