PAPR Protection Levels: Why Not All P3 Filters Are Equal

Most people think P3 filters are created equal. They’re not.

If you’re buying powered respirators for a bearded workforce, or looking for a face-fit-free RPE option, don’t just compare models on price or filter type. A P3 filter rating alone does not tell you the full protection level.

The complete unit matters. The hood, mask, fan unit, airflow, seal, classification and Assigned Protection Factor all affect how much protection the wearer actually receives.

Here’s what this guide covers:

What Does PAPR Stand For?

PAPR stands for Powered Air Purifying Respirator. It is a type of respiratory protective equipment that uses a battery-powered fan to pull air through filters and deliver filtered air to the wearer.

PAPR systems are often used where workers need respiratory protection for longer periods, where breathing resistance needs to be reduced, or where loose-fitting hoods are preferred because tight-fitting masks are unsuitable.

Loose-fitting PAPR hoods do not normally require face fit testing, but the unit still needs to provide the correct protection level for the hazard.

Wait – Aren’t All P3 Filters the Same?

In theory, yes. P3 filters are rated to capture 99.95% of airborne particulates. But in real-world use, that protection rating is only valid when the filter is paired with a unit that delivers adequate airflow and leak control.

And that’s where most people get it wrong.

What Does a P3 Filter Protect Against?

A P3 filter is designed for high-efficiency protection against airborne particulates. Depending on the full RPE system and the specific filter approval, P3 filters may be used for hazards such as fine dusts, welding fume, silica dust, wood dust, metal particulates and other harmful airborne particles.

However, a P3 particulate filter does not automatically protect against gases and vapours unless it is part of a suitable combined filter, such as an A1P3 or A2P3 filter. Filter selection must always match the substance, task and exposure level.

This is why choosing RPE based on “P3” alone can be misleading. The filter rating, facepiece or hood, airflow performance and Assigned Protection Factor all need to match the risk assessment.

Assigned Protection Factor (APF): The Missing Piece

What actually protects the wearer isn’t just the filter – it’s the Assigned Protection Factor (APF) of the whole system.

PAPR (Powered Air Purifying Respirator) systems are rated using TH (Turbo Hood) or TM (Turbo Mask) classifications. These indicate both their build and their level of protection:

Rating	Type	Face Fit Needed?	APF	Equivalent
TH1	Loose-fitting hood	❌	10	≈ FFP2
TH2	Loose-fitting hood	❌	20	≈ FFP3 / Half-mask
TH3	Loose-fitting hood	❌	40	≈ Full-face P3
TM3	Tight-fitting mask	✅	40	Full-face (requires fit test)

So yes — different powered respirators may use P3 filters, but they do not all provide the same workplace protection. A TH1 system has a UK APF of 10, while a TH3 system has a UK APF of 40. That difference matters when you are selecting RPE for higher-risk dusts, fumes or airborne contaminants.

Don’t Get Caught Out by Low-Cost Kits

The cheap £260 units you find online might seem like a smart workaround for facial hair or COSHH compliance – but many of them are only rated to TH1.

If you’re not checking the APF, you’re buying blind. And if you’re using these units for high-risk environments (e.g. fine dusts, sprays, volatile particles), that’s not just a poor decision – it’s a regulatory risk.

Buying or Issuing PAPR Systems? Ask These First:

• Is a face fit test required for the model?
• What’s the unit’s TH or TM rating?
• Is the APF suitable for the task and environment?
• How often does the unit need servicing?
• Do you have a documented RPE inspection process in place?

Not sure what protection level your team needs? We can help you review your RPE strategy, inspect current kit, and advise on compliant options for bearded operatives and specialist environments.

PAPR and P3 Filter FAQs

Here are answers to common questions about PAPR meaning, P3 filter ratings, Assigned Protection Factors and powered respirator protection levels.

What does PAPR stand for?

PAPR stands for Powered Air Purifying Respirator. It uses a powered fan unit to draw air through filters and deliver filtered air to the wearer.

What is a P3 filter?

A P3 filter is a high-efficiency particulate filter used in respiratory protective equipment. Under EN 143, P3 filters are commonly associated with a minimum filtration efficiency of 99.95% against particulates.

What does a P3 filter protect against?

A P3 filter protects against airborne particulates such as fine dusts, fumes and other harmful particles. It does not protect against gases or vapours unless combined with a suitable gas filter, such as A1P3 or A2P3.

Does a P3 filter mean the respirator has the highest protection?

Not necessarily. P3 is the highest particulate filter class, but the wearer’s protection depends on the whole RPE system, including the mask or hood, airflow, leakage and Assigned Protection Factor.

What is the difference between TH1, TH2 and TH3?

TH1, TH2 and TH3 are classifications for loose-fitting powered respirator hoods. They can all use P3 filters, but they provide different Assigned Protection Factors. TH1 has a UK APF of 10, TH2 has a UK APF of 20, and TH3 has a UK APF of 40.

Do PAPR hoods need face fit testing?

Loose-fitting PAPR hoods do not normally require face fit testing. Tight-fitting powered masks still need a face fit test because they rely on a seal to the wearer’s face.