Air Changes Per Hour (ACPH) measures how many times a room’s total air volume is filtered and replaced every 60 minutes.
It is critical in cleanrooms because it actively dilutes airborne contaminants, prevents particles from settling, shortens recovery times, and ensures strict adherence to ISO and GMP classification standards. Air Changes per Hourย are important factors in determining the design and evaluating the performance of a cleanroom.ย
๐๐ก๐๐ญ ๐๐ซ๐ ๐๐ข๐ซ ๐๐ก๐๐ง๐ ๐๐ฌ ๐๐๐ซ ๐๐จ๐ฎ๐ซ?
As defined by ISO 146144-4 standards,ย air changes per hourย refers to the number of times per hour the air in a cleanroom is replaced with clean, filtered, and treated air. Itโs calculated by dividing the volume of air sent into the cleanroom as a unit of time by the total volume of the cleanroom.ย So, if a room has an ACPH of 40, that means the air in that room is completely swapped out 40 times every hour.
๐
๐จ๐ซ๐ฆ๐ฎ๐ฅ๐
ACPH = (60 ร CFM) / Volume of Room
ACPH = Air changes per hour
CFM= Cubic feet per minute
๐๐ก๐ฒ ๐ข๐ฌ ๐๐๐๐ ๐๐จ ๐๐ฆ๐ฉ๐จ๐ซ๐ญ๐๐ง๐ญ?
In pharmaceutical manufacturing, contamination can come from people, equipment, materials, and even the surrounding air.
Without adequate air changes, contaminants can accumulate inside the cleanroom, increasing the risk of:
- Product contamination
- Microbial growth
- Batch rejection
- Regulatory observations
- Product recalls
- Risks to patient safety
Maintaining the correct ACPH helps minimize these risks and supports consistent product quality.
๐๐๐ง๐๐๐ข๐ญ๐ฌ ๐จ๐ ๐๐๐ข๐ง๐ญ๐๐ข๐ง๐ข๐ง๐ ๐ญ๐ก๐ ๐๐จ๐ซ๐ซ๐๐๐ญ ๐๐๐๐
An effective ACPH system helps pharmaceutical companies:
- Protect sterile products
- Improve product quality
- Reduce contamination risks
- Support GMP compliance
- Enhance cleanroom performance
- Prepare for successful regulatory inspections
- Safeguard patient safety
๐๐ก๐ฒ ๐๐๐๐ ๐ข๐ฌ ๐๐ซ๐ฎ๐๐ข๐๐ฅ ๐ข๐ง ๐๐ฅ๐๐๐ง๐ซ๐จ๐จ๐ฆ๐ฌ:
- Contaminant Removal & Dilution
- Cleanroom Classification Compliance
- Workspace Recovery Time
- Consistent Environmental Control
- Worker Safety & Pressure Maintenance
- ย
In pharmaceutical manufacturing, every breath of clean air is another layer of protection for the medicineโand for the patient who depends on it.