Which option correctly maps a filter type to its ISO Class?

Which option correctly maps a filter type to its ISO Class?

• A. HEPA filter ISO Class 3
• B. ULPA filter ISO Class 3
• C. HEPA filter ISO Class 5
• D. ULPA filter ISO Class 5

Answer: (B)

Understanding how filter efficiency ties to cleanroom classifications helps here. ISO classifications measure how clean the air is, with lower numbers indicating stricter standards. ULPA filters provide higher particle-removal efficiency than HEPA filters, capturing a greater fraction of very small particles. ISO Class 3 is much cleaner than ISO Class 5, so meeting ISO Class 3 requires the higher-performance filtration. HEPA, while excellent and commonly used for ISO Class 5 environments, does not meet the tighter limits of ISO Class 3. Therefore, the correct mapping is a ULPA filter to ISO Class 3.

Understanding how filter efficiency ties to cleanroom classifications helps here. ISO classifications measure how clean the air is, with lower numbers indicating stricter standards. ULPA filters provide higher particle-removal efficiency than HEPA filters, capturing a greater fraction of very small particles. ISO Class 3 is much cleaner than ISO Class 5, so meeting ISO Class 3 requires the higher-performance filtration. HEPA, while excellent and commonly used for ISO Class 5 environments, does not meet the tighter limits of ISO Class 3. Therefore, the correct mapping is a ULPA filter to ISO Class 3.