Whether it's from opening a door, people moving around, or stirring up dust, this test ensures the air filtration system, especially the HEPA filters, are performing as expected.

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What is the Recovery Test?

The Recovery Test measures how fast the cleanroom removes airborne particles and restores clean conditions after a disturbance.

It proves that the cleanroom can quickly recover to maintain its required ISO Class or GMP Grade standards.

How the Test is Done:

1️⃣ Introduce Particles

- The air is intentionally disturbed by opening doors, moving personnel, or using an aerosol generator to add particles.

2️⃣ Measure Particle Levels

- A Particle Counter monitors the airborne particle levels to record the level of contamination.

3️⃣ Time the Recovery

- Using a stopwatch or timer, the time is recorded to see how long it takes for the room to return to acceptable particle levels.

Pass or Fail?

- Pass – If the particle count returns to cleanroom standards within the required time (typically ≤ 15–20 minutes).

- Fail – If recovery takes too long, it may signal problems with airflow rates, HEPA filter performance, or room design.

Equipment Used:

- Particle Counter – Accurately counts airborne particles.

- Stopwatch/Timer – Measures the recovery time.

- Aerosol Generator – (Optional) Introduces a known amount of particles to challenge the system.

Why Recovery Testing Matters:

- Verifies HEPA filter efficiency and air change rates

- Ensures quick removal of contamination after disturbances

- Maintains regulatory compliance (ISO 14644-1, GMP)

- Protects products, processes, and patient safety in critical industries

Need Cleanroom Validation Services?

At Aimtech Systems LLP, we offer complete Recovery Testing along with:

- Certified Particle Counting Equipment

- Detailed, audit-ready validation reports

- Professional, trained validation engineers