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DOP Testing

Ensure your HEPA filtration system is performing safely, efficiently, and in full compliance with industry standards.

Our certified engineers provide accurate and reliable DOP testing for cleanrooms, laboratories, HVAC/LEV systems, and high-risk industrial environments.

Dispersed Oil Particulate Testing

What Is DOP Testing?

A HEPA (High-Efficiency Particulate Air) filter removes extremely small particles from the air, such as dust, allergens, bacteria, and other contaminants, to keep your environment clean and safe.

DOP (Dispersed Oil Particulate) testing checks how effectively a HEPA filter captures these tiny airborne particles. A compliant filter should remove 99.95% to 99.99% of particles, and DOP testing shows whether it meets that standard.

During the test, a controlled aerosol (oil mist) is introduced into the system, and we measure how much particulate passes through the filter:

  • If almost nothing gets through, your filter is performing correctly.
  • If any leakage is detected, the filter fails the test, but we can pinpoint exactly where the issue is.
dop testing
dop testing hepa filter

Ensuring HEPA Filter Integrity

Why Is DOP Testing Important?

DOP testing is essential to make sure your HEPA filtration system is working properly. It gives you confidence that your environment is safe, your operations meet compliance standards, and your filters are performing at their best.

DOP Testing:

  • Proves HEPA filter efficiency
  • Ensures compliance with industry and insurance requirements
  • Protects staff and processes from airborne contaminants
  • Identifies leaks or weak points within the filtration system
  • Prevents downtime by catching issues early
  • Maintains air quality in sensitive environments

Regular DOP testing is essential for any system where filtration performance cannot be left to chance.

Industry-Specific DOP Testing

Industries We Support

We provide DOP testing across a range of sectors, including:

Cleanrooms

 

Laboratories

Pharmacy

Food

Hospitals

 

Manufacturing

HVAC

LEV

What’s Involved in a DOP Test?

U

System Inspection

We assess your unit, filters, and safety conditions. We identify any performance issues and recommend the right actions to keep your system running efficiently.

Aerosol Generation

A harmless mist of Shell Ondina oil is introduced to simulate the behaviour of airborne particulates.

Filter Challenge Test

Photometers measure particle penetration. This verifies how effectively your filters capture airborne contaminants.

Integrity Check

We detect and pinpoint leaks or damaged seals. Any compromised areas are identified so they can be corrected immediately.

Certification & Report

You receive full documentation and results. Most tests are completed with minimal downtime to your operations.

DOP Testing FAQs

Frequently Asked Questions

What does DOP testing stand for?

Dispersed Oil Particulate testing, which is a method for checking HEPA filter integrity.

Which oil is used in a DOP test?

Although it is still called “DOP testing,” the original chemical (dioctyl phthalate) is no longer used due to safety concerns. Today, safer alternatives are used instead, such as Shell Ondina oil in the UK, to test the integrity of HEPA filters.

How often should DOP testing be done?

Typically, HEPA filters should be tested every 12 months, or more frequently in high-risk industries.

Do I need DOP testing if I already replace filters regularly?

Yes, as replacement alone doesn’t confirm correct installation or integrity.

dop testing

Expert HEPA Integrity Testing

Why Choose Us for DOP Testing?

  • Certified HEPA and DOP testing engineers
  • Experienced across industrial, pharmaceutical, and high-risk sites
  • Accurate, reliable testing with calibrated equipment
  • Clear, easy-to-understand reporting
  • Minimal disruption to your operations
  • Full compliance with industry standards
  • Fast, dependable testing
  • Complete peace of mind

Ensure safety, compliance and high performance from your HEPA filtration system. Speak to our team or schedule your DOP testing today.

Built on Compliance and Safety Excellence

OUR SERVICES

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Your single-source provider

Why choose Impact

We are a single-source provider for all workplace dust, fume, vapour and oil mist extraction requirements.

From LEV testing and system design to installation and ongoing maintenance, our services are delivered by BOHS-qualified technicians and overseen by CoC-qualified management — ensuring fully compliant, reliable and effective extraction solutions throughout the life of your system.

Experienced

30 years of nationwide coverage

Qualified

P601, P602, P603, P604 qualified LEV technicians

Outstanding Service

We have a high percentage of returning customers

Expertise

Experts in LEV project management

Warranty

12 month warranty on all installations