You have invested in a Powered Air Purifying Respirator (PAPR) system. The blower runs. The battery charges. The hood fits comfortably.

But none of that matters if you choose the wrong filter.

At Junsee Group, we see this mistake often. A factory buys an excellent PAPR system but uses particulate-only filters for a job that requires gas protection. Or they use combination filters for a dust-only application — paying for capability they do not need.

Choosing the correct PAPR filter is not complicated. You simply need to answer two questions:

1. What is the hazard? (Particulates? Gases? Both?)

2. What protection level do I need? (TH1, TH2, or TH3?)

This guide walks you through every filter type, color code, and application — so you can match the right filter to your specific workplace contaminants.

Part 1: Identify Your Hazard — Particulates, Gases, or Both?

Before you select any filter, you must know what is in the air your workers breathe.

Hazard Type 1: Particulates (Dust, Fumes, Mists, Fibers)

Particulates are solid or liquid particles suspended in the air. They include:

Key question: Is the contaminant a solid particle or liquid droplet that you can see (at high concentration) or feel on surfaces? If yes, you need a particulate filter .

Hazard Type 2: Gases and Vapors

Gases and vapors are molecular contaminants — too small to be captured by a particulate filter alone. They include:

Key question: Does the air smell like chemicals? Are workers reporting eye irritation, dizziness, or headache? If yes, you likely need a gas cartridge — not just a particulate filter.

Hazard Type 3: Combined Hazards (Particulates + Gases)

Many workplaces have both particulates and gases. Examples include:

Solution: Use a combination filter — typically a HEPA particulate filter layered with an activated carbon gas cartridge .

Part 2: Particulate Filters — Understanding Efficiency Ratings

Once you confirm you need particulate protection, you must choose the correct efficiency level.

PAPR Particulate Filter Standards

Key fact: For PAPR systems, NIOSH requires HEPA filters for particulate protection . These filters remove 99.97% of particles down to 0.3 microns — and are even more efficient for larger and smaller particles.

PAPR Performance Classes (EN 12941)

The European standard EN 12941 defines three protection classes for PAPR systems with hoods or helmets :

Example: The Sealey PAPR system meets TH2 class according to EN 12941 — suitable for most general industrial dust applications .

Pre-Filters: Extend the Life of Your Main Filter

Many PAPR systems use a two-stage filtration approach:

Junsee Group tip: Using a pre-filter extends the life of your expensive HEPA filter by 3-5x. Never run a PAPR without a pre-filter in dusty environments .

Part 3: Gas Cartridges — Color Codes and Chemical Compatibility

If your workplace contains gases or vapors, you need a gas cartridge — not just a particulate filter.

EN Color Code System for Gas Cartridges

Real-World Cartridge Examples

Important: Not All PAPR Systems Include Gas Protection

Some PAPR systems — particularly those designed for general dust or healthcare applications — ship with particulate-only filters.

✅ Example: The Sealey PAPR system includes a foam pre-filter and HEPA filter designed for dust and particles only — not vapors and gases .

✅ Example: The 3M Versaflo TR-600-HK Healthcare PAPR Kit includes a TR-6710N HE Particulate Filter. Gas and vapor protection can be provided with cartridges not part of this kit .

Junsee Group recommendation: If your workplace contains any gases or vapors, verify that your PAPR system accepts gas cartridges. Not all systems do.

Part 4: Combination Filters — When You Need Both

For workplaces with both particulates and gases, you need a combination filter. These are typically labeled with both a particulate rating and a gas color code.

Which Combination Filter Should You Choose?

Part 5: Protection Level — TH1, TH2, or TH3?

Beyond filter type, PAPR systems themselves are classified by protection level under EN 12941 .

How to Choose the Right Class

Example: The 3M Versaflo S-433L-5 hood system provides an APF of 1000 (TH3 equivalent) — reducing contaminant concentration inside the hood to 1/1000th of outside air .

Part 6: Special Applications — Cleanroom and Healthcare Filters

Some industries require specialized PAPR filters designed for cleanroom or healthcare environments.

Cleanroom PAPR Filters

In pharmaceutical manufacturing and sterile processing, PAPR filters must :

• Not shed fibers (low-linting construction)

• Withstand harsh decontamination (IP67-rated blowers for submersion cleaning)

• Trap sub-micron particles (HEPA or ULPA efficiency)

Example: The 3M Versaflo TR-600 for cleanrooms uses:

• TR-6710N HE Filter (high efficiency particulate)

• IP67-rated blower for full submersion decontamination

• Non-porous TR-627 belt that will not harbor microbes 

Healthcare PAPR Filters

For healthcare workers performing aerosol-generating medical procedures (AGMPs) , PAPR filters must :

• Meet NIOSH HEPA standards

• Optionally include gas cartridges for chemical disinfection vapors (USP 800 compliance)

• Be compatible with disposable hoods for single-use protocols

Example: The 3M Versaflo TR-600-HK Healthcare PAPR Kit includes a TR-6710N HE Particulate Filter — and can accept gas cartridges for USP 800 compliance when handling hazardous drugs .

Part 7: Filter Replacement — When to Change Your PAPR Filter

Choosing the right filter is only half the battle. You must also know when to replace it.

Particulate Filters (HEPA, P-series)

Junsee Group tip: In heavy dust environments, pre-filters may need daily replacement. Main HEPA filters typically last 3-6 months.

Gas Cartridges (Activated Carbon)

Gas cartridges are more difficult to know when to replace because:

• You cannot see saturation

• Carbon has a finite capacity for adsorbing gas molecules

• Once saturated, gases pass through unchanged

⚠️ Critical warning: Unlike particulate filters (which get harder to breathe through), gas cartridges provide no physical warning of saturation. You may be breathing contaminated air without knowing it. Always follow manufacturer replacement schedules .

Combination Filters

Follow the most conservative rule for whichever component fails first. If the gas cartridge is saturated but the particulate filter is clean — replace the entire combination filter.

Summary: PAPR Filter Selection Quick Reference

The Junsee Group Recommendation

At Junsee Group, we help customers select the right PAPR filter for every application. Our process:

1. Identify the hazard — Particulates, gases, or both?

2. Measure concentration — Is TH1, TH2, or TH3 required?

3. Select filter type — HEPA, gas cartridge, or combination

4. Verify compatibility — Ensure filter fits your PAPR model

5. Set replacement schedule — Based on usage, environment, and manufacturer guidance

The bottom line: The best PAPR in the world provides zero protection with the wrong filter. Take the time to match your filter to your hazard — your workers' lungs depend on it.

Need help selecting the right PAPR filter for your workplace?
Contact Junsee Group today. We will help you identify your hazards, calculate required protection levels, and choose the correct filter — the first time.