Cleanroom Classifications


In addition to the following Cleanroom Cleanliness Classifications, cleanroom facilities are certified in three (3) Modes of Operation and as defined per ISO 14644-1

1. As-Built - Installation is complete with all services connected and functioning but with no production equipment, material or personnel present. The certification in this mode is only done after it is build, remodeled or upgraded.

2. At Rest - Installation is complete, equipment and operating in a mode of operation agreed upon by the customer and the suppler, but with no personnel present. Certification is frequently done in this mode of operation

3. Operational - Installation is complete, equipment is operational, personnel is present. Certification is frequently done in the mode of operation.

Know what your cleanroom is doing: Do a 24 hour airborne particle count profile (set particle counter up on 15 minute interval) in the operational mode of operation annually to provide a real time benchmark of what your cleanroom is really doing. This will prove invaluable when troubleshooting a airborne contamination investigation. This can also be done in an At-Rest mode of operation for comparison purposes.


On-going monitoring and logging of the airborne particle counts and pressure differentials is a major key to keeping your cleanroom operating at optimal efficiency. 

Regardless of when you do the particle counting profile, make sure you document the elevation of the particle counter probe on your report!

For more information to better aid your cleanroom questions,  start out by downloading our articles on the the first page of our website or give us a call at  585-621-6946.

Per ISO 14644-1

Design Class High Limits


At 0.5 Microns       At 5.0 Microns
Fed Std 209e ISO   ISO Class   Fed Std 209e ISO
1 35   3   0 0
10 352   4   0 0
100 3,520   5   0 29
1,000 35,200   6   7 293
10,000 352,000   7   70 2,930
100,000 3,520,000   8   700 29,300
N/A 352,000,000   9   N/A 293,000

R. Kraft, Inc
478 Manse Lane 
Rochester, NY 14625
United States of America

Tel: (585) 621-6946
Email: for more information

Let our 45 + yrs of cleanroom experience

assist you in achieving and operating a cost effective cleanroom facility.

( 3rd Party Certification, Troubleshooting, Performance Appraisals, Training Seminars, Design Assistance from a Service Provides viewpoint, Construction/Project Management)

R. Kraft Inc. is a

3rd Party

ISO/IEC 17025:2017 Accredited Laboratory,

Testing and Certifying Cleanrooms and Laminar Flow Devices


236210 - 238220 - 325412 - 326111 - 326112 - 541380 - 541611 - 541614 - 541620 - 541910 - 541990 -561210 - 611430 

             Cage: 3EVT1



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