HEPA filter integrity testing with the PAO and DOP methods

A cleanroom can pass every other check and still be compromised by a single leak point in a HEPA filter. Vanavil Calibrations tests HEPA filter media, frames and seals using industry-standard aerosol challenge methods, with a documented result for every filter.

HEPA filter integrity testing is the on-site verification that a High-Efficiency Particulate Air (HEPA) filter — along with its frame and seal — has no leak point compromising its ability to capture airborne particulates. Vanavil Calibrations carries out HEPA filter integrity testing using the PAO (Poly-Alpha-Olefin) and DOP (Dioctyl Phthalate) aerosol challenge methods, as part of our validation services across Tamil Nadu.

Confirming a HEPA filter is still doing its job

HEPA filters degrade quietly. Physical damage during handling or maintenance, seal wear around the frame, and media fatigue over years of service can all open a leak path — none of it visible during a routine walk-through, and none of it reliably caught by a room-level particle count alone.

HEPA filter integrity testing answers a narrower, more specific question than a whole-room test: not whether the space in general is in spec, but whether this particular filter, its frame and its seal has a defined point where unfiltered air can pass through.

Technician inspecting a HEPA filter installation for integrity testing

A compromised filter undermines everything downstream of it

Contamination Breakthrough

A single leak point in the filter media, frame or seal lets unfiltered air bypass into a controlled space, undermining everything else the room is designed to control.

Compliance Failure

HEPA integrity is a specific, auditable checkpoint in pharmaceutical, healthcare and laboratory quality systems — a room can look compliant elsewhere and still fail on this point.

Product & Patient Risk

In sterile manufacturing and clinical spaces, a compromised filter puts product sterility and patient safety at direct risk — not just a paperwork gap.

How we check HEPA filter integrity

PAO and DOP testing are the industry-standard aerosol challenge methods used to verify HEPA filter integrity. A calibrated aerosol is introduced upstream of the filter, and a scan is taken downstream — across the filter face, frame and seal — to detect any point where the aerosol is passing through instead of being captured.

  • Aerosol challenge testing using the PAO or DOP method
  • Scan of the entire filter media face for leak points
  • Scan of the filter frame and gasket/seal for bypass leakage
  • Check of filter mounting and housing integrity
  • Airflow uniformity across the filter face
  • Documented result for every filter tested

Where HEPA filter integrity testing gets used

  • Pharmaceutical cleanrooms
  • Hospital operation theatres & isolation areas
  • Laminar flow cabinets
  • Biosafety cabinets

Healthcare

Operation theatres & critical care

Pharmaceutical

Manufacturing & sterile areas

Laboratories

Research & QC environments

Industrial

Precision manufacturing

01

Filter Assessment

We review the filter's installation, access and prior test history to plan the check.

02

Aerosol Challenge Testing

PAO or DOP aerosol challenge testing is carried out against ISO IEC 17025:2017 procedures.

03

Documented Report

You receive a report identifying the filter tested and its result, ready for your quality records.

04

Remediation Advice

Where a leak point is found, we advise on next steps for repair or replacement.

NABL-Accredited

Calibration and validation carried out under NABL accreditation and ISO/IEC 17025:2017.

On-Site & Laboratory Capability

We test HEPA filters on-site in their installed location, backed by laboratory capability for wider validation needs.

One Accountable Team

Filter testing, room validation and documentation come from a single accredited provider, not multiple vendors.

PAO (Poly-Alpha-Olefin) and DOP (Dioctyl Phthalate) testing are aerosol challenge methods used to check HEPA filter integrity. A calibrated aerosol is introduced upstream of the filter, and a scan is taken downstream — across the filter media, frame and seal — to detect any point where the aerosol is bypassing the filter instead of being captured.
This depends on the filter's application, the room's classification and your regulatory framework. We recommend a suitable interval as part of every engagement rather than applying a fixed schedule to every facility.
We document the leak point's location and extent, and advise on next steps — which may include filter repair, reseating or replacement — so the filter can be re-tested and confirmed before the space is returned to service.

Need your HEPA filters checked?

Tell us about your filters and their installed location — we'll scope the aerosol challenge test and schedule.