Unlocking Precision: The Science Behind Clean Room Technology

Clean rooms are crucial in industries like pharmaceuticals, electronics, and aerospace, where even tiny particles can impact product quality. They provide controlled environments for tasks like microchip manufacturing and medical device assembly.

Key features include HEPA air filtration systems and materials that minimize particle generation. Strict protocols, such as wearing specialized garments and thorough cleaning, maintain cleanliness.

Clean rooms are classified from ISO Class A (cleanest) to ISO Class D (least clean), with guidelines on particle counts and airflow rates. They not only prevent product contamination but also ensure worker safety and environmental protection.

In summary, clean rooms are vital for maintaining precision, quality, and safety in various industries. Through meticulous design and rigorous protocols, they enable the production of high-quality products and support research and development efforts.

 

The specified size range for particle counts in clean rooms varies depending on the class. Here's a breakdown:

Class A Clean Room: The specified size range typically includes particles ranging from 0.1 micrometers to 0.5 micrometers in size. This class demands the strictest cleanliness standards, as even minute particles can impact sensitive processes, such as semiconductor manufacturing or pharmaceutical production.

Class B Clean Room: This class maintains a slightly higher level of cleanliness compared to Class A. The specified size range often encompasses particles ranging from 0.5 micrometers to 1 micrometer in size. Class B clean rooms are commonly found in industries like biotechnology, where precision and control over airborne contaminants are crucial.

 

Class C Clean Room: Class C clean rooms allow for a higher level of particle contamination compared to Class B. The specified size range typically includes particles ranging from 1 micrometer to 5 micrometers in size. These clean rooms are suitable for industries where a moderate level of cleanliness is sufficient, such as certain pharmaceutical packaging facilities.

 

Class D Clean Room: This class has the highest allowable particle count among the classifications, but still maintains a controlled environment suitable for many manufacturing processes. The specified size range often includes particles ranging from 5 micrometers to 10 micrometers in size. Class D clean rooms are essential for industries where a basic level of cleanliness is required, such as some assembly or testing operations.

 

Understanding the specified size range is crucial for designing, operating, and maintaining clean rooms to ensure they meet the cleanliness standards required for their intended applications.

The particle count for each class of clean room is as follows:

SI No	Clean Room Class	Partial Size	Particle Qty / ft3	Particle Qty per M3	Remark
1	Class A	0.1 µ ~ 0.5 µ	1	35,315
2	Class B	0.5 µ ~ 1 µ	10000	353,150
3	Class C	1 µ ~ 5 µ	100000	3,531,500
4	Class D	5 µ ~ 10 µ	1000000	35,315,000

 GMP Annex European Community Cleanroom Standards:

Grade	At Rest >0.5 um/M3	At Rest >5um/M3	Operational >0.5um/M3	Operational >0.5um/M3	Equivalent ISO at rest/ operational	Equivalent Fed209E at rest / operational
A	3,520	20	3,520	20	ISO-5/5	100/100
B	3,520	29	352,000	2,900	ISO-5/7	100/10k
C	352,000	2,900	3,520,000	29,000	ISO-7/8	10k/100k
D	3,520,000	29,000	not defined	not defined	ISO-8/na	100k/na

 

ISO 14644-1 Cleanroom Standards | Cleanroom Classifications:

Class	Maximum  Particles/m³						FED STD 209E equivalent
	>0.1 um	>0.2 um	>0.3 um	>0.5 um	>1 um	>5 um
ISO 1	10	2
ISO 2	100	24	10	4
ISO 3	1,000	237	102	35	8		Class 1
ISO 4	10,000	2,370	1,020	352	83		Class 10
ISO 5	100,000	23,700	10,200	3,520	832	29	Class 100
ISO 6	1,000,000	237,000	102,000	35,200	8,320	293	Class 1,000
ISO 7	not defined	not defined	not defined	352,000	83,200	2,930	Class 10,000
ISO 8	not defined	not defined	not defined	3,520,000	832,000	29,300	Class 100,000
ISO 9	not defined	not defined	not defined	35,200,000	8,320,000	293,000	Room Air

 

References:

1.         Kowalski, W. Cleanroom Technology: Fundamentals of Design, Testing and Operation. John Wiley & Sons, 2010.

2.         Whyte, W. Cleanroom Design. Butterworth-Heinemann, 2000.

3.         ISO 14644-1:2015, Cleanrooms and associated controlled environments – Part 1: Classification of air cleanliness.

4.         Ljungqvist, B., Reinmüller, B., & Vogt, C. (Eds.). The EC GMP Guide Annex 1: Manufacture of Sterile Medicinal Products. CRC Press, 2017.

5.         Yamamoto, H. (Ed.). Cleanroom Technology: Second Edition. CRC Press, 2017.

Author

Md Rayhan Chowdhury

CTO

LABMIT