MSA 464046 GMC Organic Vapor / Acid Gas Cartridge for Comfo Respirators — Box of 10

MSA GMC Cartridge Overview

The MSA GMC Organic Vapor / Acid Gas Cartridge (SKU 464046) is a NIOSH-approved, dual-class air-purifying cartridge that simultaneously controls organic vapor and acid gas exposures using a two-stage activated and impregnated carbon sorbent bed — sold as a box of 10 at $103.45 ($10.35 per unit). It mounts on MSA Comfo-platform respirators via the proprietary threaded bayonet fitting, replacing the need to stack separate single-class cartridges in mixed-exposure tasks.

Before selecting any cartridge, confirm that your specific hazard profile matches the GMC's approved protection scope. The respirator cartridge selection guide walks through the full NIOSH classification system, and the respirator filter types explained guide covers the differences between vapors, gases, and particulate filtration. For the complete MSA Comfo-series cartridge lineup, see the MSA Respirator Filters & Cartridges collection. If your work also involves silica dust, review the best respirator for silica dust before committing to this cartridge alone.

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Where the MSA GMC Fits in Respirator Selection

Cartridge selection starts with hazard identification, not brand preference. The GMC is appropriate when an industrial hygienist or SDS review confirms both organic vapor and acid gas hazards are present simultaneously — for example, a process using toluene (organic vapor) in a bath that also off-gasses hydrogen chloride (acid gas). Choosing a single-class cartridge such as the MSA GMA organic vapor cartridge or the MSA GMB acid gas cartridge in a co-exposure scenario leaves one hazard class uncontrolled.

If the hazard profile extends to ammonia, methylamine, or formaldehyde alongside OV/AG, the MSA GME multigas cartridge or MSA GMT multi-gas cartridge may be the correct step up. If particulates are also present, the GMC alone is insufficient — see the GMC-P100 combination cartridge. The respirator cartridge color-coding chart explains how NIOSH color bands distinguish each hazard class.

Who Should Buy the MSA GMC?

What Does the MSA GMC Protect Against?

The GMC combines activated carbon (organic vapor adsorption) with impregnated carbon (acid gas neutralization) in a single sorbent bed. The table below covers the primary hazard categories, protection status, and buyer guidance for each.

What the MSA GMC Does NOT Protect Against

• Particulates of any kind — no filter media is present; pair with the MSA Low-Profile P100 filter or step up to the GMC-P100
• Ammonia and methylamine — use the MSA GMD or GME
• Mercury vapor — requires a specialized activated carbon impregnated for mercury; see the Mersorb P100
• Carbon monoxide, methane, or other non-reactive gases without established sorbent affinity
• Formaldehyde — not within the GMC's approved scope; review the GME multigas cartridge for broader coverage
• Radioactive particulates or iodine vapor — use the MSA GMI Iodine P100 cartridge

Best Applications for the MSA GMC Cartridge

Solvent-Based Spray Painting and Coating

Workers applying solvent-based paints, lacquers, or industrial coatings in enclosed spaces often encounter organic vapor loads from thinners alongside trace acid gas off-gassing from certain catalyst systems. The GMC addresses both hazard classes in a single cartridge change. For environments where the coating also generates spray mist or overspray particulates, pair with the GMC-P100. See the best respirator for welding fumes guide for guidance on tasks combining heat and chemical vapors.

Chemical Manufacturing and Processing

Processes involving chlorinated solvents — such as chloroform, methylene chloride, or trichloroethylene — produce both organic vapor and acid gas breakdown products. Maintenance personnel working near acid-wash lines, chemical reactors, or chlorination systems benefit from the GMC's dual-class coverage. The full MSA cartridge lineup supports a range of chemical plant hazard profiles beyond OV/AG.

Battery Maintenance and Acid Handling

Forklift battery rooms and industrial battery maintenance generate sulfuric acid mist and hydrogen gas. Where electrolyte solvents or cleaning agents co-exist with acid gas exposure, the GMC provides coverage for both. For tasks where battery acid mist (particulate form) is the primary concern, confirm whether a P100 filter is also required.

Laboratory and Research Environments

Laboratory technicians working with organic solvents in the presence of acids — such as hydrochloric acid or acetic acid vapor — find the GMC a practical single-cartridge solution versus managing two separate cartridge types. For background on selecting among available cartridge classes, the organic vapor vs P100 guide explains when vapor-only protection is sufficient versus when particulate filtration must be added.

MSA GMC Pros and Cons

Compatible MSA Respirators

The GMC uses MSA's threaded bayonet (GM-series) fitting. Verify your respirator's cartridge connection system before ordering. Browse the full MSA full-face respirator collection and MSA half-mask respirator collection to confirm model compatibility.

MSA GMC vs Other MSA GM-Series Cartridges

All cartridges below use the same GM-series threaded bayonet mount and are sold in the MSA Respirator Filters & Cartridges collection. Select based on your confirmed hazard class, not cartridge color.

MSA GMC vs MSA GMC-P100 — Which Do You Need?

This is the most commercially significant comparison for GMC buyers: the GMC-P100 adds a P100 particulate filter layer to the identical OV/AG sorbent bed. The decision is entirely driven by whether particulates are present in your work environment.

MSA GMC vs MSA GMA — OV Only vs OV/AG Combo

Buyers who know their process generates acid gas breakdown products sometimes consider whether the simpler GMA organic vapor cartridge is adequate. It is not, if acid gases are confirmed. The table below clarifies the upgrade decision.

MSA GMC Quick Answers

What does the MSA GMC cartridge protect against?

The MSA GMC cartridge provides NIOSH-approved protection against organic vapors (solvents such as acetone, toluene, xylene, and MEK) and acid gases (including chlorine, hydrogen chloride, sulfur dioxide, and hydrogen fluoride) simultaneously. It does not filter particulates, ammonia, or mercury vapor.

What respirators does the MSA GMC cartridge fit?

The GMC uses MSA's GM-series threaded bayonet mount and fits the Comfo Classic (Hycar and Silicone), Comfo II, Advantage 200 LS half-masks, and the Ultra-Twin and Ultra-Elite full-face respirators. It does not fit 3M, Moldex, Honeywell North, or any non-MSA GM-series respirator.

Does the MSA GMC cartridge filter dust or mist?

No. The GMC contains only a sorbent bed for gas and vapor adsorption — there is no mechanical filter media. If particulates are present alongside organic vapor and acid gas, the correct choice is the MSA GMC-P100 combination cartridge, which adds a P100 filter stage to the same OV/AG sorbent.

How many cartridges come in one box and what is the per-unit cost?

Each box contains 10 cartridges (one pair = 2 cartridges for one respirator change-out). At $103.45 per box, the per-unit cost is $10.35. Most half-mask change-outs require 2 cartridges per use, so one box covers 5 complete half-mask loadings.

How do I know when to replace the MSA GMC cartridge?

The GMC does not include an end-of-service-life indicator (ESLI). Replacement should follow a documented change-schedule based on OSHA's change schedule requirements, including consideration of contaminant concentration, temperature, humidity, breathing rate, and cartridge age from opening. Consult your industrial hygienist to establish a site-specific schedule.

Is the MSA GMC the same as the MSA GMC-P100?

No. The GMC is a vapor/gas-only cartridge. The GMC-P100 adds a P100 particulate filter layer rated at 99.97% filtration efficiency for airborne particles. The sorbent beds provide the same OV/AG coverage, but only the P100 variant handles dust, mist, or aerosols.

What is the MSA GMC part number and GTIN?

The MSA GMC Organic Vapor / Acid Gas Cartridge carries part number (SKU) 464046 and GTIN 0641817007549. These identifiers appear on product labeling and can be used to cross-reference procurement records or Safety Data Sheet lookups.

MSA GMC Cartridge Specifications

Helpful Buying Guides

• How to Choose a Respirator Cartridge — Complete Selection Guide
• Respirator Filter Types Explained — Particulate, Gas, Vapor, and Combination
• Organic Vapor vs P100 — When Vapor-Only Protection Is (and Isn't) Enough
• NIOSH Respirator Cartridge Color Chart — How to Read Your Cartridge Label
• Best Respirator for Welding Fumes — Cartridge and Mask Selection Guide
• 3M Filter and Cartridge Guide — How 3M Cartridges Compare to MSA and Moldex
• Best Respirator for Silica Dust (2026) — P100 and Combination Options

MSA GMC Frequently Asked Questions

Can I use the MSA GMC cartridge on a 3M half-mask respirator?

No. The GMC uses MSA's GM-series threaded bayonet fitting, which is not interchangeable with 3M's bayonet system. If you own a 3M 6000 or 7500 series respirator and need OV/AG protection, the correct equivalent is the 3M 6003 or 60923 cartridge. Mixing cartridges and respirators from different connection systems creates an unsealed fit and negates NIOSH approval.

Does the GMC protect against chlorine gas?

Yes. Chlorine is classified as an acid gas under NIOSH 42 CFR Part 84, and the GMC is NIOSH-approved for acid gas protection — which includes chlorine, hydrogen chloride, sulfur dioxide, and hydrogen fluoride. If chlorine is the primary or sole hazard and organic vapor is not present, the MSA GMB acid gas cartridge is a leaner option at lower cost.

How long does the MSA GMC cartridge last before it needs to be replaced?

There is no fixed shelf-life or use-life stamped on the GMC; service life depends on contaminant concentration, temperature, relative humidity, breathing rate, and whether the cartridge was sealed after partial use. OSHA 29 CFR 1910.134 requires employers to implement a written change schedule. A qualified industrial hygienist should determine the change interval for your specific contaminant levels. Discard immediately if you detect odor or irritation breakthrough while wearing the cartridge.

Is the MSA GMC cartridge reusable?

Yes — the GMC is a reusable-respirator cartridge intended for use across multiple work sessions, subject to the employer's documented change schedule. Unlike disposable respirators, the cartridge is replaced as a consumable while the facepiece (Comfo Classic, Comfo II, etc.) is retained. Once a cartridge has reached its change interval, discard both cartridges from the pair simultaneously even if only one has been in service.

Can I add a P100 prefilter to the GMC for dusty environments?

The GMC itself does not accommodate a snap-on prefilter in the way some snap-fit MSA platforms do. For environments requiring both OV/AG and particulate protection on a Comfo-platform respirator, the engineered solution is the GMC-P100 combination cartridge, which integrates the P100 filter stage into the cartridge body. Do not attempt to layer aftermarket prefilters not designed for this cartridge; doing so voids the NIOSH approval.

Does the MSA GMC work with the MSA Ultra-Elite full-face respirator?

Yes. The Ultra-Elite accepts GM-series bayonet cartridges, including the GMC. When used with a full-face respirator, the assigned protection factor increases from APF 10 (half-mask) to APF 50, meaning the Ultra-Elite combination provides up to 50 times the ambient contaminant concentration as the maximum use concentration. Browse the MSA full-face respirator collection for compatible facepieces.

How does the MSA GMC compare to the 3M 6003 cartridge?

Both provide NIOSH-approved OV/AG protection in a dual-class cartridge format. The key difference is platform: the GMC fits only MSA GM-series respirators; the 3M 6003 fits 3M 6000/7500/6500 series respirators. Neither cartridge is cross-compatible. For a platform-agnostic comparison of MSA, 3M, and Moldex OV/AG cartridges, the cartridge selection guide covers all three brands side by side.

What does "acid gas" mean in the context of this cartridge?

Under NIOSH 42 CFR Part 84, "acid gas" refers to inorganic acids and acid-forming gases including chlorine (Cl2), hydrogen chloride (HCl), sulfur dioxide (SO2), and hydrogen fluoride (HF). These are chemically neutralized by the impregnated carbon in the GMC's sorbent bed. The acid gas designation does not cover acetic acid vapor or other organic acids, which fall under the organic vapor classification. The filter types guide explains the complete NIOSH classification system.

Will the GMC protect against paint thinner and chlorine in the same environment?

Yes — this is precisely the dual-class exposure scenario the GMC is designed for. Paint thinner vapors (organic vapor class) and chlorine off-gassing (acid gas class) are simultaneously controlled by the GMC's two-stage sorbent bed. If spray mist or aerosol from the paint is also present, upgrade to the GMC-P100 to add particulate protection.

What is the shelf life of an unopened box of MSA GMC cartridges?

MSA publishes a shelf life for their GM-series cartridges from the date of manufacture when stored in original sealed packaging at controlled temperature and humidity (typically 5 years; verify with current MSA documentation for your specific lot). Once opened or exposed to contaminated air, the manufacturer's stated storage life no longer applies and the employer's change schedule governs replacement. Check lot date codes on packaging and rotate stock on a first-in, first-out basis.

Do I need two GMC cartridges per respirator use?

Yes. All half-mask and full-face respirators in the MSA Comfo platform use one cartridge per side (two cartridges per facepiece). A box of 10 GMC cartridges provides five complete loadings for one respirator. Always replace both cartridges simultaneously — replacing only one creates an unbalanced sorbent bed and may result in premature breakthrough on the exhausted side.

Is the MSA GMC cartridge approved for use with supplied air?

No. The GMC is an air-purifying cartridge and is only approved for use as part of an air-purifying respirator (APR) system. It cannot be combined with supplied-air or airline respirator configurations. Supplied-air respirators do not use cartridges; they deliver breathing air from an external compressed source via a hose or airline. If your environment requires supplied air — due to IDLH conditions or oxygen deficiency — an APR with this cartridge is not appropriate.