Guardtech Nordic AB Cleanroom Blog: Pressure Cascade – a critical parameter that can’t be overlooked

June 23, 2025

This month the Guardtech Nordic AB team take a closer look at the deliberate control of air pressure between different areas of a cleanroom facility

When it comes to controlled environments, you’ll often hear us talk about stuff like air filtration, ISO classification and gowning protocols — but one of the most critical controls is often overlooked: Pressure Cascade – the deliberate control of air pressure between rooms.

Okay then – what’s that?

Well, it’s the principle of maintaining higher air pressure in cleaner rooms, so air naturally flows outward, not inward – protecting critical zones from contamination.

And why exactly does it matter?

Contamination Control – stops airborne particles from less clean areas entering sensitive spaces.

Compliance – meets strict standards from ISO, FDA, EMA and other regulatory bodies.

Process Zoning – creates clear boundaries between different cleanliness levels and processes.

Safety in Containment Areas – in reverse cascade set-ups, negative pressure helps contain toxic or active substances.

Typical Cleanroom Pressure Cascade:

  • Grade B (ISO 7): +15 Pa
  • Grade C (ISO 8): +10 Pa
  • Grade D: +5 Pa
  • Unclassified: 0 Pa

Air flows from the cleanest to the least clean – it’s a simple concept with a powerful impact!

Key to Success:

  • Ensure you have reliable HVAC and BMS controls
  • Airlocks and proper door interlocks need to be utilised
  • Continuous pressure monitoring & alarms must be in situ
  • Thorough and regular validation & maintenance programmes


A well-designed pressure cascade protects your product, your process and your people. It’s not just airflow – it’s control, compliance and peace of mind.

Email Guardtech Nordic AB Director Lars Strandljung on l.strandljung@guardtech.com to begin your journey to cleanroom success!