The standard for compressed air quality, particularly regarding oil content, is primarily defined by ISO 8573-1. While no air is technically 100% free of oil molecules, the classification considered the standard for the highest level of air purity concerning oil, often referred to in industry as "oil-free," is ISO 8573-1 Class 0.
Understanding ISO 8573-1 Class 0
ISO 8573-1 is an international standard that specifies air quality classes for compressed air with respect to particles, water, and oil. Different classes are defined for each contaminant, allowing industries to select the appropriate air quality based on their specific application requirements.
Within this standard, Class 0 represents the most stringent air quality classification. It was specifically introduced to address critical applications where even minimal contamination could have severe consequences.
- Key Requirement for Class 0: To meet ISO 8573-1 Class 0, compressed air must contain less than 0.01 milligram per cubic meter (mg/m3) of total oil. This limit covers oil aerosol, liquid oil, and oil vapor.
Why is Class 0 Important?
Industries like pharmaceuticals, food and beverage, electronics, and medical applications require extremely high air purity. In these sectors, the presence of oil in compressed air can lead to:
- Product contamination or spoilage.
- Equipment damage or malfunction.
- Health risks in medical or dental applications.
- Compromised process integrity.
Choosing compressed air generation equipment certified to produce air meeting ISO 8573-1 Class 0 ensures the highest level of protection against oil contamination.
Achieving Class 0 Air
Producing air that meets the strict requirements of Class 0 typically involves using specialized compressor technologies, such as:
- Oil-free compressors: These compressors are designed so that no oil is present in the compression chamber, preventing oil from coming into contact with the compressed air.
- Advanced filtration systems: While oil-free compressors are key, additional high-performance filters are often used to remove any potential residual oil vapor or other contaminants to ensure Class 0 compliance.
ISO 8573-1 Oil Classes Comparison
While the reference highlights Class 0, it's useful to understand how it compares to other oil classes defined by ISO 8573-1:
| ISO 8573-1 Oil Class | Maximum Total Oil Content (mg/m³) | Common Applications |
|---|---|---|
| Class 0 | < 0.01 | Food & Beverage, Pharmaceutical, Medical, Electronics |
| Class 1 | < 0.01 | Similar critical applications, often specified slightly differently than Class 0 depending on interpretation. |
| Class 2 | < 0.1 | General industrial applications requiring clean air |
| Class 3 | < 1 | Less critical industrial applications |
| Class 4 | < 5 | Standard industrial applications, power tools, conveyors |
Note: Class 0 is the most rigorous and was created specifically to address the absolute highest purity needs, going beyond Class 1 in terms of testing and guarantees.
