Compressed air might look clean, but it can carry hidden contaminants like oil aerosols or vapor, moisture and particles. These contaminants can cause problems for your equipment, processes and products. ISO 8573-1 is the global standard for compressed air purity, providing a clear framework for managing air quality.
This guide explains what ISO 8573-1 is, why it matters for your operations and the steps you can take to help you achieve compliance without unnecessary complexity.
Why Compressed Air Quality Matters
When air quality falls short, your equipment and processes suffer. Contaminated compressed air can wear down pneumatic tools and components, create product quality issues and lead to failed inspections and unexpected downtime.
Meeting ISO 8573-1 compressed air purity standards can help safeguard both products and production. The required purity level is determined by the production process and the type of machinery in use. It helps with maintenance costs and unplanned repairs. It also supports consistent product quality and can assist facilities with their audit and regulatory compliance programs.
What Does ISO 8573-1 Cover?
ISO 8573-1 defines compressed air quality in three categories:
- Particles such as rust, dust and pipe debris
- Water in the form of humidity, liquid or vapor
- Oil as aerosols and vapor
Each type is given a rating. The lower the class number, the cleaner the air.
How to Comply with ISO 8573-1: Key Steps
Verify What Your System Delivers
Before making changes to your system, it’s a good idea to have an expert assess your current setup. A qualified specialist can evaluate what equipment is installed and determine which ISO 8573-1 purity class your system is currently achieving. This can be documented as part of your system records. If there’s a gap between the required air quality and the actual conditions, our experts can provide guidance and support to help you close that gap effectively.
Choose the Right Dryers and Filters
Moisture control is essential for meeting ISO classes:
- Refrigerant dryers typically reach Class 4 moisture levels
- Desiccant dryers achieve very low dew points, suitable for Class 1 or 2
- Membrane dryers work well for point-of-use drying, typically used for Class 2
To complement dryers, filters tackle other contaminants:
- Particulate filters help remove solid particles like dust and rust
- Coalescing filters help remove oil and water aerosols
- Activated carbon filters (optional) help remove oil vapors and odors for high-purity applications
Place Equipment Strategically
Dryers should be installed early in the system to reduce moisture before air reaches filters and downstream equipment. Filters placed at key points downstream help protect critical equipment and processes from contamination.
Keep Up with Maintenance and Monitoring
- Track pressure drops across dryers and filters
- Replace filter elements and service dryers according to manufacturer guidelines
- Keep detailed records to support audits and identify performance trends
The Bottom Line for ISO 8573-1 Compliance
ISO 8573-1 is not just a technical requirement. It is a practical way to maintain clean, reliable compressed air that supports equipment performance and process quality. With the right mix of dryers, filters and maintenance, you can help meet your air quality targets to keep your operations running smoothly.
Whatever industry you’re in, ISO 8573-1 compliance helps provide clean air and system reliability.
Looking to improve and document your compressed air quality?
Donaldson’s service team can assess your system and measure air purity in line with ISO 8573. We offer a full range of filtration and drying solutions to help you comply with the required classes for particles, water and oil. Reach out to our experts to design the best system for your needs.
