MSA GMB/P100 Respirator Cartridge — Acid Gas/P100 (MSA Comfo)

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Read our MSA GMB/P100 review for the detailed review.

MSA GMB/P100 Respirator Cartridge Overview

The MSA GMB/P100 is a NIOSH-approved combination cartridge for MSA Comfo respirators that protects against acid gas AND airborne particulate in one unit. The built-in P100 filter captures at least 99.97% of particles, so the MSA GMB/P100 covers gas plus dust without a separate prefilter. Start with the cartridge selection guide, the organic vapor vs P100 guide and the color chart.

As a Comfo combination cartridge it fits the MSA Comfo Classic, Comfo II, Ultra-Twin and Ultra-Elite, and belongs to the MSA respirator filters and cartridges range. Choose the gas-only GMB if there is no dust; the MSA GMB/P100 when gas and particulate are both present.

Where the MSA GMB/P100 Fits in Cartridge Selection

The MSA GMB/P100 handles acid gas and airborne particulate. If you are weighing gas-only versus combination cartridges, our filter types explained and Comfo vs Advantage guides help you decide.

Who Should Buy the MSA GMB/P100?

Buy it if your work mixes acid gas with dust or mist on an MSA Comfo facepiece. Choose the gas-only GMB if there is no dust. For a broader gas mix, see the MSA Comfo GME/P100 multi-gas cartridge.

What Does the MSA GMB/P100 Protect Against?

What the MSA GMB/P100 Does NOT Protect Against

The MSA GMB/P100 does not stop organic vapor, ammonia or formaldehyde. For a different gas, match the MSA cartridge to the hazard; for a broad mix use the GME/P100 multi-gas version.

No air-purifying cartridge makes a dangerous atmosphere safe. Never use the MSA GMB/P100 in an oxygen-deficient or IDLH (immediately dangerous to life or health) atmosphere, in unknown concentrations, or against gases with no warning properties — those conditions require a supplied-air or SCBA system, not a cartridge respirator. A cartridge or filter carries no assigned protection factor of its own — the APF comes from the facepiece it is fitted to: 10 for a half mask, 50 for a full facepiece (OSHA 1910.134 Table 1), which is the number that decides the highest exposure the respirator may legally be worn in. That facepiece must be fit tested before first use and at least annually, and a fit test is specific to one make, model, and size — passing on one mask does not carry over to another. Perform a user seal check every time the respirator is donned, and note that facial hair crossing the sealing surface disqualifies a tight-fitting respirator no matter how well it fit at the last test.

Best Applications

Chlorine handling with dust

Treatment and plating with acid gas plus aerosol.

Etching

Acid baths that release gas and mist.

Pros & Cons

MSA GMB/P100 vs Other MSA Cartridges

MSA GMB/P100 vs the Alternatives

How it compares to the closest MSA options:

• GMB/P100 vs GMB: same acid gas; the GMB/P100 adds a P100 filter for dust.
• GMB/P100 vs GMC/P100: the GMC/P100 also covers organic vapor.
• GMB/P100 (Comfo) vs Advantage GMB/P100: same chemistry, different facepiece system.

MSA GMB/P100 Quick Answers

Does the MSA GMB/P100 need a separate filter?

No — the P100 filter is built in; there is no prefilter or retainer to add.

Does the MSA GMB/P100 fit my MSA respirator?

It fits the MSA Comfo family; check your facepiece in the MSA half-mask and full-face ranges.

Is the MSA GMB/P100 reusable?

The cartridge is used until its gas or filter service life is reached; the respirator is reusable across many changes.

MSA GMB/P100 Specifications

Compatible MSA Respirators

The MSA GMB/P100 uses the MSA Comfo threaded-bayonet connection, so it mounts on the Comfo Classic half-mask and Ultra-Elite full-face respirators (and the Comfo II and Ultra-Twin). It is not interchangeable with the MSA Advantage series, and does not fit 3M, Honeywell North or other brands.

Helpful Buying Guides

• MSA Comfo vs Advantage
• How to choose a respirator cartridge
• MSA vs 3M respirator cartridges
• MSA vs Honeywell North cartridges
• organic vapor vs P100
• respirator cartridge color chart
• respirator filter types explained

MSA GMB/P100 Frequently Asked Questions

What does the MSA GMB/P100 protect against?

The MSA GMB/P100 is a acid gas / P100 combination cartridge. It captures chlorine, hydrogen chloride and sulfur dioxide and filters at least 99.97% of airborne particulate. It does not protect against organic vapor, ammonia or formaldehyde.

Does the MSA GMB/P100 filter dust?

Yes. The MSA GMB/P100 has a built-in P100 filter that captures at least 99.97% of airborne particles, including oil-based mists, so no separate prefilter is needed.

Which respirators does the MSA GMB/P100 fit?

It uses the MSA Comfo threaded-bayonet connection (Comfo Classic, Comfo II, Ultra-Twin, Ultra-Elite). It does not fit the Advantage series.

What does P100 mean on the MSA GMB/P100?

P100 is the highest NIOSH particulate rating: oil-proof and at least 99.97% efficient. The MSA GMB/P100 carries a magenta P100 marking alongside its gas-class band.

Is the MSA GMB/P100 NIOSH-approved?

Yes, under 42 CFR Part 84 for its listed gases and P100 particulate. Verify against the NIOSH Certified Equipment List.

How is the MSA GMB/P100 sold?

This listing is the Each. Use ask a distributor for case pricing.

How often should I replace the MSA GMB/P100?

Replace the gas portion on your written change-out schedule, or when an end-of-service-life indicator shows it is spent. Under 29 CFR 1910.134(d)(3)(iii)(B) the change schedule must rest on objective data or an end-of-service-life indicator — odour, taste or irritation may not be the primary basis. If you can smell or taste anything through the cartridge, breakthrough has already happened: leave the area immediately and change it. Also replace it and replace when breathing through the P100 filter becomes noticeably harder.

Does the MSA GMB/P100 need a separate filter?

No. The P100 particulate filter is built in, so there is no prefilter or retainer to add.

What is the difference between the MSA GMB/P100 and the gas-only version?

Choose the gas-only GMB if there is no dust; the MSA GMB/P100 when gas and particulate are both present.

What color band is the MSA GMB/P100?

The markings are white (ag) + magenta (p100); confirm both your gas class and the P100 on the color chart.

Is this the genuine MSA GMB/P100 cartridge?

Yes. Buy authentic, NIOSH-approved MSA GMB/P100 cartridges through legitimate channels only.

How should I store the MSA GMB/P100?

Store it sealed in its original packaging, away from gases and dust, so neither the gas nor filter service life is used up before use.