Pharmaceutical powders range from benign excipients to highly potent APIs. Airborne particulate threatens worker health, product quality, and cross-contamination. Robust controls are essential across weighing, granulation, compression, and packing.

Segregation and pressure cascades

Design rooms so air flows from clean to dirty. Use negative pressure in dispensing and granulation areas, with positive pressure protecting finished product spaces. Check pressure differentials daily and maintain clear make-up air routes.

High-efficiency air filtration

Employ high-grade HEPA filtration for recirculation and exhaust. Where potency or critical cleanliness demands, use H14, and in niche cases ULPA filtration. Focus on correct housings and seals to prevent bypass. Base unit sizing on airflow under load and consider filter loading over the batch.

Capture at source

Use local exhaust ventilation such as downflow weighing booths, slot capture at transfer points, and enclosed charging where possible. Optimise techniques before PPE: slower pour rates, lined containers, and closed transfer reduce dust release.

Housekeeping without re‑aerosolisation

Ban sweeping and air lances. Use H-class industrial vacuums with suitable HEPA filtration for floors, equipment frames, and ledges. Change pre-filters on a set schedule and document cleaning as part of batch records to support GMP and COSHH.

Monitoring and change control

Trend PM1/PM2.5 data in high-risk rooms during operations and cleaning. Investigate any spikes aligned with door openings, bag changes, or equipment stops. After modifications, recheck capture performance and pressure cascades.

Practical takeaways

• Maintain pressure cascades with daily checks and clear airflow paths.
• Use H14 filtration where potency or cleanliness requires it; prevent bypass.
• Prioritise enclosed transfers and LEV at tipping and weighing.
• Vacuum-only cleaning with H-class units; schedule filter changes.
• Trend particulate data and verify controls after any change.

By combining segregation, high-efficiency filtration, source capture, and disciplined cleaning, pharmaceutical sites can protect people and product while keeping batch flow efficient.