Hepa Filter Integrity

Filtech Testing Division

HEPA Filter
Integrity

Leak testing is a critical quality control process for HEPA and ULPA filters, ensuring their integrity and effectiveness in controlled environments. Filtech uses advanced equipment and methods to conduct precise leak testing, so every bit of air meets the high standards expected from these filters.

NSF/ANSI 49-2020 HEPA & ULPA 0.3 Micron Challenge

HEPA filter leak testing with a photometer probe

HEPA and ULPA Filter Leak Testing

Why Filtech

Pinhole Leak DetectionAdvanced equipment pinpoints even the tiniest pinhole-sized leaks with precision.

Tec Services PH5 PhotometerPaired with an aerosol generator emitting 0.3-micron smoke particles.

Repairs & PatchingDOW RTV sealant used to patch detected holes and restore filter compliance.

NSF/ANSI 49-2020All leak testing procedures follow current NSF standards.

Particle Size Matters: 0.3 Microns

0.3 µm

Test Particle Size

99.97%

HEPA Efficiency Rating

0.01%

Max Penetration, Scanned

Understanding the significance of 0.3 microns in leak testing is crucial. This particle size is considered the most penetrable and challenging for HEPA filters to capture, so it serves as a critical test particle size to determine a filter's efficiency rating. Filtech uses a Tec Services PH5 Aerosol Photometer paired with an aerosol generator that emits 0.3-micron smoke particles to assess HEPA filter performance.

Most challenging: 0.3-micron particles are among the most difficult for HEPA filters to capture, making them an excellent indicator of filter efficiency.
Worst-case scenario: testing at this particle size ensures that even the smallest potential leaks are detected, guaranteeing the highest level of safety.

Detection, Repairs & Patching

Our advanced equipment and expertise allow us to pinpoint even the tiniest pinhole-sized leaks in HEPA and ULPA filters with precision. This meticulous approach ensures that no leaks go unnoticed, maintaining the integrity of your controlled environment.

In the event of a detected leak, Filtech's technicians are well-equipped to provide expert HEPA and ULPA filter repairs. We use DOW RTV sealant to patch any holes, ensuring that the filter meets the necessary standards and remains in optimal working condition.

Test Procedures Per NSF Standards

The leak testing procedures employed by Filtech adhere to NSF/ANSI 49-2020 standards.

Methods for Testing HEPA/ULPA Filters

Filters That Can Be Scanned

Assessed by introducing an aerosol into the cabinet and scanning the downstream side of the filter with a photometer probe.

Filters That Cannot Be Scanned

Where exhaust filters cannot be scanned, a hole is drilled in the duct downstream and the photometer probe is inserted for testing.

For both methods, reported values include upstream aerosol challenge concentration, maximum leak penetration, the method used for reporting concentration, the testing method used (scanned or probe tested), and the test name.

Acceptance Criteria

0.01% max

For filters that can be scanned, sustained aerosol penetration must not exceed 0.01% of the upstream concentration at any point.

0.005% max

For filters that cannot be scanned, sustained aerosol penetration must not exceed 0.005% of the upstream concentration.

Establishing & Maintaining Filter Efficiency

HEPA filters are known for their exceptional efficiency in capturing and retaining particles as small as 0.3 microns, with a 99.97% efficiency rating. However, even the tiniest hole or defect in a HEPA filter's structure can compromise its performance. By conducting rigorous leak tests, we verify the integrity of the filter, ensuring it is free from leaks or defects.

Regulatory bodies, such as the National Sanitation Foundation, have established strict standards for HEPA filters, including specific criteria for filter integrity and leak rates. HEPA filters must meet these criteria to be considered efficient. Leak testing helps demonstrate compliance with these standards, reinforcing the filter's efficiency rating.

What Leak Testing Delivers

Performance assurance: the 99.97% efficiency rating is based on the filter's ability to capture and retain particles with a very high level of efficiency. Leak testing identifies and addresses any issues that could compromise this performance.
Preventing contamination: in cleanrooms, laboratories, and healthcare facilities, leak testing helps prevent potential contamination by ensuring the filter effectively captures and retains particles, pathogens, and contaminants.
Long-term efficiency: filters experience wear and tear over time or physical damage during installation and maintenance. Regular leak testing as part of routine maintenance identifies issues early, extending filter lifespan and maintaining the efficiency rating.

Schedule Leak Testing

At Filtech, we are committed to the integrity and efficiency of your HEPA and ULPA filters. Send us your filter types and quantities, equipment or room locations, and preferred timing for leak testing or repair service.