Understanding DOP Testing for Asbestos Vacuums: A Complete UK Guide

What is DOP Testing and Why Does It Matter?

If you work with asbestos in the UK, you'll know that using a properly certified Type-H vacuum isn't optional—it's a legal requirement. But what exactly is DOP testing, why does it need repeating every six months, and what happens during the test? This complete guide answers all your questions.

What is DOP Testing?

DOP stands for Dispersed Oil Particulate, a testing method used to verify that HEPA and ULPA filters in asbestos vacuums are working correctly. The test introduces microscopic oil particles into the vacuum and measures how many escape through the filter.

For a vacuum to pass:

• HEPA H13 filters must capture 99.97% of particles at 0.3 microns
• ULPA H14 filters must capture 99.999% of particles at 0.12 microns

Any filter that fails to meet these standards cannot be used for asbestos work.

Why is DOP Testing Required?

The Control of Asbestos Regulations 2012 and BS 8520-3:2009 require that all Type-H asbestos vacuums are DOP tested:

• Before first use (initial certification)
• Every 6 months during operation
• After any filter replacement

The reason is simple: asbestos fibres are invisible to the naked eye and extremely dangerous. A damaged or clogged filter could release fibres back into the air, exposing workers and contaminating clean areas. Regular testing ensures the filter is still providing adequate protection.

What Happens During a DOP Test?

The DOP testing process involves several critical steps:

1. Visual Inspection

The vacuum is inspected for physical damage, worn seals, or any defects that could compromise containment.

2. Filter Integrity Test

Microscopic oil particles (DOP aerosol) are introduced into the vacuum's intake. A photometer then measures particle concentration upstream (before the filter) and downstream (after the filter). Any leak or filter damage will show an increase in downstream particles.

3. Airflow Verification

The vacuum must maintain minimum airflow of 20 metres per second to ensure effective capture of asbestos fibres. This is why most Type-H vacuums include a built-in airflow indicator light.

4. Electrical Safety Testing

The vacuum is tested to BS EN 60335-2-69 standards to ensure it's electrically safe to operate.

5. Certification

If the vacuum passes all tests, a DOP test certificate is issued showing the test date, pass/fail result, next test due date (6 months), serial number of vacuum, and details of the testing company.

How Much Does DOP Re-Testing Cost?

Initial DOP certification is typically included when you purchase a new Type-H asbestos vacuum from a reputable supplier like Atrix Vacuums UK.

For re-testing every 6 months, expect to pay approximately £120 + VAT. This includes the DOP test, electrical safety test, filter replacement (if required), new certification, and return shipping.

Many suppliers offer automatic reminder services so you don't miss your re-test dates.

Can I Use My Vacuum Without Valid DOP Certification?

No. Using an asbestos vacuum without valid DOP certification is a breach of the Control of Asbestos Regulations 2012. You could face:

• Prohibition notices from HSE
• Prosecution for safety violations
• Insurance claims being voided if an incident occurs
• Reputational damage to your business

If your DOP certificate has expired, the vacuum must be taken out of service immediately until re-tested.

What About Non-Licensed Asbestos Work?

Even for non-notifiable asbestos work (below HSE notification thresholds), you're still required to use properly certified Type-H vacuums. The regulations don't distinguish between licensed and non-licensed work when it comes to equipment standards.

This includes:

• Asbestos surveying (HSG264)
• Domestic asbestos removal
• Maintenance work on asbestos-containing materials
• Emergency response (Fire Services)

Common DOP Testing Questions

Q: Why can't I test the vacuum myself?

DOP testing requires specialized equipment (photometers, DOP aerosol generators) and trained technicians. The test must be performed by an accredited testing company in a controlled environment.

Q: Can I replace the filter myself between tests?

No. ULPA filters in asbestos vacuums must only be replaced by trained professionals in appropriate facilities. Attempting to change an asbestos vacuum filter yourself could expose you to contaminated material.

Q: What if I only use my vacuum occasionally?

The 6-month rule still applies regardless of usage frequency. A filter can degrade over time even if not in use, due to moisture absorption, material breakdown, and seal deterioration.

Q: Do battery-powered asbestos vacuums need DOP testing?

Yes. Battery-powered vacuums like the Battery Omega Plus still require 6-month DOP certification. The power source doesn't affect filtration requirements.

Ensuring Compliance

When purchasing a Type-H asbestos vacuum, ensure:

• Initial DOP certification is included
• Vacuum is registered for re-test reminders
• You have access to an accredited testing company
• You keep records of all DOP certificates

At Atrix Vacuums UK, every Type-H asbestos vacuum we supply includes a 6-month DOP test certificate dated and registered, electrical safety test certificate, automatic re-test reminder service registration, and contact details for accredited re-testing companies.

This ensures you're compliant from day one and have a clear path for ongoing certification.

Need a DOP-certified asbestos vacuum? Browse our Type-H Asbestos Vacuum range or call our technical team on 0800 756 1331 for expert advice.

All Atrix Type-H asbestos vacuums are supplied with 6-month DOP certification as standard.