EP: Official Guidance on the Relationship Between the European Pharmacopoeia and ISO 8573-1 for Process Compressed Air

Core requirements for process compressed air in the European Pharmacopoeia

The European Pharmacopoeia explicitly lists process compressed air as a medium that may come into direct contact with medicinal products or pharmaceutical raw materials in its relevant general chapters. Its primary focus is on controlling particulate matter, moisture, oil content, and microbial load in the air to ensure that these do not adversely affect product quality, safety, or efficacy. The standard requires that compressed air undergo appropriate purification and that its quality be regularly verified at critical points of use. For sterile preparations or production lines handling highly active substances, the Pharmacopoeia typically mandates more stringent filtration and drying processes, while also emphasizing the traceability of the air‑supply system and the implementation of periodic revalidation procedures.

ISO Classification Logic of Standard 8573-1

ISO 8573-1 is an internationally recognized standard for classifying compressed air purity, which defines grades based on three categories of contaminants: solid particles (classified by particle size and concentration), water vapor (expressed as pressure dew point), and oil content (including liquid oil mist, gaseous oil vapor, and total oil levels). The standard employs a numerical grading system, where lower numbers indicate higher purity. For example, Class 1 It is the highest purity grade and is commonly used in precision manufacturing and high-risk industries. Class 2 To Class 8 The limit values are then gradually relaxed, making them suitable for typical industrial applications. The testing methodology encompasses sampling protocols, instrument calibration, and data‑recording procedures, ensuring that the results are both comparable and reproducible.

The intersection and correspondence between the two in the pharmaceutical industry

The European Pharmacopoeia does not make direct reference. ISO The specific grade designation of 8573-1, yet it is highly consistent in technical substance. Pharmaceutical companies typically translate the pharmacopoeial qualitative requirements into… ISO Quantifiable indicators for 8573-1. In general, process air in standard non-sterile operations shall meet Class 2 or Class 3 The limits for moisture and oil content, combined with a high-efficiency particulate filter; meanwhile, compressed air used in product-exposed areas often needs to meet Class 1 or Class 2 Particle control levels, supplemented by sterilizing-grade filtration. In practical applications, enterprises should select an appropriate compressed air quality grade based on the specific process risk level and demonstrate compliance through third-party test reports or internal validation data.

Key Steps in Compliance Implementation

• Needs Assessment: Define the minimum quality threshold for each gas‑use point based on product dosage form, frequency of contact, and cleaning difficulty.
• System Design: Properly configure pre-filters, refrigerant or desiccant dryers, and terminal sterilizing filters to prevent pipeline dead zones and condensate accumulation.
• Verification Strategy: Conduct continuous sampling tests during the installation qualification and operational qualification phases, covering peak operating conditions and extreme environmental scenarios.
• Continuous monitoringDeploy online differential pressure gauges, dew point meters, and oil mist sensors; set alarm thresholds; and establish an anomaly response procedure.

Common Misconceptions and Maintenance Recommendations

Some enterprises exhibit an over-reliance on a single piece of equipment or neglect regular replacement of consumables in their air‑supply management. In reality, the service life of pre‑treatment units and terminal filters is significantly influenced by inlet air humidity, temperature fluctuations, and usage frequency. It is recommended to establish a preventive maintenance schedule and dynamically adjust replacement intervals based on manufacturer specifications and historical data. Additionally, avoid connecting instrument air and process air to the same piping network to prevent cross‑contamination. Prior to each shutdown and restart, perform a purging procedure and re‑verify critical parameters to ensure the system returns to its initial clean‑state. Standardizing operating records and conducting trend analysis can substantially enhance air‑supply stability and improve audit compliance rates.