Overview
Compressed air is one of the most critical utilities in pharmaceutical manufacturing, used for instrumentation, process equipment operation, material conveying, and direct product contact applications. Quality monitoring ensures compliance with cGMP requirements and prevents product contamination.
Applications in Pharmaceutical Manufacturing
- Instrumentation Air – Pneumatic actuators, control valves, instruments
- Process Air – Tablet coating, fluid bed drying, material conveying
- Breathing Air – Supplied-air respirators and emergency breathing systems
- Plant Air – General maintenance, cleaning, equipment operation
- Sterile Air – Direct product contact applications requiring sterility
Quality Specifications
USP Medical Air Specifications
- Identification: Methods A and B
- Oxygen Content – 19.5%-23.5% O₂ by volume
- Limit of Carbon Dioxide – Not more than 500ppm
- Limit of Carbon Monoxide – Not more than 5ppm
- Sulfur Dioxide – Not more than 10ppm
- Limit of Nitric Oxide and Nitrogen Dioxide – Not more than 2.5ppm
- Water and Oil Content – None discernable
Other considerations
- Particulate Matter – Class 1 per ISO 8573-1
- Bioburden
ISO 8573-1:2010 Air Quality Classes
Solid Particles:
- Class 1: ≤0.1 mg/m³, ≤20,000 particles/m³ (0.1-0.5 μm), ≤400 particles/m³ (0.5-1.0 μm), ≤10 particles/m³ (1.0-5.0 μm)
- Class 2: ≤1 mg/m³, ≤400,000 particles/m³ (0.1-0.5 μm), ≤6,000 particles/m³ (0.5-1.0 μm), ≤100 particles/m³ (1.0-5.0 μm)
- Class 3: ≤5 mg/m³, ≤90,000 particles/m³ (0.5-1.0 μm), ≤1,000 particles/m³ (1.0-5.0 μm)
Water Content:
- Class 1: ≤-70°C pressure dew point
- Class 2: ≤-40°C pressure dew point
- Class 3: ≤-20°C pressure dew point
- Class 4: ≤+3°C pressure dew point
Oil Content:
- Class 1: ≤0.01 mg/m³ total oil (aerosol + vapor)
- Class 2: ≤0.1 mg/m³ total oil
- Class 3: ≤1 mg/m³ total oil
Pharmaceutical Grade Compressed Air
- Typical Specification: ISO 8573-1 Class 2.2.1 or better
- Microbial Quality: <10 CFU/m³ for process air, sterile for direct contact
- Chemical Purity: No detectable hydrocarbons, CO, CO₂ <500 ppm
- Pressure: 6-8 bar gauge, stable ±0.1 bar
- Flow Rate: Adequate for peak demand with 25% safety margin
Microbial Specifications
- Process Air: <10 CFU/m³ total viable count
- Breathing Air: <10 CFU/m³, absence of pathogens
- Sterile Air: Sterility test, no growth in 14-day incubation
- Clean Room Supply: Grade A: <1 CFU/m³, Grade B: <10 CFU/m³
Sample Handling
- Sample Points – Representative sampling locations in distribution system. Sample cylinders can be sampled by our trained technicians or shipped by the customer.
- Supply Cylinders – may be shipped directly for testing of a batch or sampled on site.
- Pressure Regulators – Two-stage pressure reduction for stable pressure.


