Changes in ISO 14644-1: Classification of Air cleanliness


After a long time of 5 years, ISO 14644-1 has been changed, new changes are useful to improve the clean room standard in pharmaceuticals manufacturing sterile as well as the oral dosages form.

ISO Technical Committee 209 has been working on the revision of the basic airborne cleanliness classification standard for the last 4 years. Its drafts are already published in 2011, 2012, 2014 and 2015 but none was finalized. Revision of guidance was started since 2007.

Finally ISO 14644-1, 2015 version is released and following are major changes:

1. Title “Classification of air cleanliness” of the ISO 14644-1 is replaced from “Classification of air       cleanliness by particle concentration”.

2. A new table has been developed for the determination of the number of sample locations, replacing “N-L = √A” from the 1999 version of the standard. For all room sizes above 6m square, the new table results in an increase in required sample locations. New table give below.

Now Calculation formula of the particle concentration (Cn) in respective classification number is not used, value is taken from table.


3. Now UCL calculation is not required. There is no need to perform an observation of all measuring points in the room may longer.

4. Each single measuring point is considered individually and has to meet the limit value.

5. Particle of  5 micron in ISO Class 5 have been removed from the limit value. Table is given below


6.Tubing length of particular counter should be less than 1 meter.

There is no changes in classification number, air sample volumes and measuring time as well as the cancellation criterion. 

According to new guideline, all SOPs and qualification protocols in pharmaceuticals manufacturing related to the HVAC and clean room management should be changed.   

Read More : Revision to Cleanroom Standard: ISO 14644 Parts 1 and 2