In food production, compressed air directly contacts food or production equipment, and its quality directly affects food safety. The following are the core standards and application specifications for compressed air for food:
1. international common standards
1. ISO 8573-1:2010 Quality Levels
- solid particulate matter:
- direct contact with dry food (such as milk powder and grain):≤ 1 grade (≤ 0.1μm particles ≤ 2000/m & sup3;)
- direct contact with non-dry food (such as beverages and meat):≤ 2 (≤ 0.1μm particles ≤ 10000/m & sup3;)
- indirect contact (such as packaging workshop environment):≤ 3
- moisture content:
- direct contact with dry food: ≤ 2 (pressure dew point ≤-40 ℃)
- direct contact with non-dry food: ≤ 3 (pressure dew point ≤-20 ℃)
- indirect contact: ≤ 4 (pressure dew point ≤ +2 ℃)
- oil content:
- direct contact with food: ≤ 1 grade (oil residue ≤ 0.01 mg/m & sup3;)
- indirect contact: ≤ 2 level (oil residue ≤ 0.1 mg/m & sup3;)
2. ISO 22000 Food Safety Management System
- compressed air systems are required to incorporate HACCP (Hazard Analysis and Critical Control Points) plans to identify and control risks such as microbiological and chemical residues.
2. key parameter requirements
| Indicators | direct contact with food | indirect contact with food |
|---|
| temperature | ≤ 40 ℃ (avoid oil volatilization caused by high temperature) | ≤ 40 ℃ |
| humidity | ≤ 0.01 mg/m & sup3;(dry food is more strict) | ≤0.1mg/m³ |
| oil | ≤ 0.01 mg/m & sup3;(oil-free compressor + catalytic oxidation purification) | ≤ 0.1 mg/m & sup3;(high efficiency filter) |
| microorganisms | ≤ 100CFU/m & sup3;(UV or ozone sterilization required) | ≤ 1000CFU/m & sup3;(regular disinfection) |
| pressure dew point | ≤-40 ℃ (adsorption dryer) | ≤ +2 ℃ (freeze dryer) |
specification for design and use of 3. system
- equipment selection:
- oil-free compressor: Avoid lubricating oil pollution (such as food-grade water-lubricated screw machines).
- Post-processing equipment:
- adsorption dryer (pressure dew point ≤-40 ℃)
- 0.01μm precision filter (filtration efficiency ≥ 99.99)
- catalytic Oxidation Purifier (decomposes oil vapors into CO₂ and H₂ O)
- pipeline Design:
- made of 316L stainless steel or food grade plastic piping.
- Avoid dead corners and water points, with a slope ≥ 1:100.
- Separate food contact piping from non-contact piping to avoid cross-contamination.
- Operation Specification:
- regular inspection: weekly detection of oil, moisture, particulate matter; monthly microbial detection.
- Maintenance records: Keep for more than 2 years, including filter element replacement and desiccant regeneration records.
- Emergency plan: Standby dryers, purification equipment, start response within 2 hours of contamination.
4. special scene requirements
- fermentation and stirring:
- compressed air must be aseptic (e. g. HEPA filtration + UV sterilization).
- Oxygen content control (to avoid oxygen enrichment leading to microbial reproduction).
- Packaging and Filling:
- use a separate compressed air circuit (not mixed with production ambient air).
- Pressure dew point ≤-40 ℃ (to prevent condensation water from contaminating the package).
- Cold chain storage:
- dry air is used to defrost cold chain equipment (to avoid water mist contact with food).
5. compliance certification
- domestic in line with the National Food Safety Standard General Hygienic Code for Food Production (GB 14881).
- International: BRC (British Retail Consortium) food grade compressed air certification.
By strictly enforcing these standards, food companies can ensure the safety and compliance of their compressed air systems and the quality of their end products. It is recommended that a third-party agency be commissioned quarterly for full-project testing and annual ISO system review.
