3M 60923 OV/P100/Acid Gas Respirator Cartridge Review: Adding Acid Gas Protection Beyond the Standard OV/P100 Cartridge
The 3M 60923 OV/P100/Acid Gas Respirator Cartridge fills a critical protection gap that many safety managers discover only after reviewing their SDS library with an industrial hygienist: standard OV/P100 cartridges (like the 60921) provide zero protection against acid gases. The 60923 adds acid gas sorbent chemistry to the OV+P100 combination, providing triple-layer protection for environments where solvents, acid gases, AND particulate matter are present simultaneously. This review covers the 60923's specific acid gas protection profile, how it differs from the 60922, target applications across auto body, bleaching, acid etching, and pulp/paper industries, and key OSHA compliance considerations.
NIOSH Approvals: OV (TC-19C), Acid Gas (TC-23C), P100 (TC-84A)
Protects Against: Organic vapors, acid gases (Cl2, HCl, SO2, H2S at low conc.), P100 particulate (99.97%)
Compatible Respirators: 3M 6000-series, 3M 7000-series half-masks (verify current 3M compatibility chart)
Does NOT Protect Against: Ammonia, formaldehyde (at PEL), carbon monoxide, IDLH concentrations
Sold As: 1 pair
Understanding the Acid Gas Addition: What Changes from 60921
The 60921 OV/P100 is appropriate for environments with only organic vapors and particulate. The moment acid gases enter the picture — even as secondary or intermittent hazards — the 60921 is no longer compliant for that specific chemical. OSHA's respiratory protection standard requires protection against all identified hazards above action levels, not just primary hazards.
The 60923 adds an acid gas sorbent layer that provides protection against:
- Chlorine (Cl2): OSHA ceiling limit 1 ppm. Generated by bleaching processes, pool chemical addition, and certain chemical reactions involving hypochlorite.
- Hydrogen Chloride (HCl): OSHA ceiling 5 ppm. Present in PVC combustion, semiconductor processes, and as a byproduct of chlorinated solvent decomposition.
- Sulfur Dioxide (SO2): OSHA PEL 5 ppm TWA. Found in pulp/paper bleaching, combustion of sulfur-containing fuels, and certain chemical synthesis operations.
- Hydrogen Sulfide (H2S) at low concentrations: Below IDLH (100 ppm); found in oil/gas, wastewater, and fermentation environments.
These acid gases are NOT captured by the activated carbon in a standard OV cartridge. A worker using a 60921 in an environment with HCl, Cl2, or SO2 is receiving zero protection against those specific chemicals while believing they're fully protected — a compliance failure and a health hazard.
60923 vs. 60922: The Form Factor Question
This is the most common point of confusion between these two cartridges, and it's worth addressing directly: the 60922 and 60923 provide similar protection profiles (both cover OV + acid gas + P100), but they are different products designed for potentially different facepiece compatibility.
The key distinction is form factor and which specific 3M respirator bodies each is approved for. Before selecting between 60922 and 60923, verify current 3M compatibility charts for your specific facepiece model. The 3M filter cartridge guide includes compatibility matrices. For the 60922's application profile and industries, see the 60922 review.
For practical purposes: if both are compatible with your facepiece, either will provide the OV+acid gas+P100 protection you need. Differences in profile height, weight, and dead-space volume between the two may influence preference in certain applications.
Target Applications for the 60923
Automotive Body and Paint Shops
Auto body repair involves a diverse chemical palette: polyurethane primers, solvent-borne basecoats and clearcoats (OV), acid etching primers (HCl or phosphoric acid, acid gas), metal treatment chemicals (zinc phosphate conversion coatings, which may release acid gas vapors), and paint spray mist (P100 particulate). The 60921 covers only the OV and particulate components — the acid etching primers and metal treatment chemicals require the acid gas layer that the 60923 provides.
Safety managers at multi-bay body shops face the practical challenge that different booths may be working on different stages simultaneously. The 60923 simplifies PPE management by covering the full chemical scope without requiring workers to switch cartridges between tasks.
Bleaching Operations
Industrial bleaching — in textiles, paper, food processing, and commercial cleaning — uses chlorine-based bleaching agents (sodium hypochlorite, calcium hypochlorite, chlorine dioxide) that release chlorine gas and hypochlorous acid vapors at use concentrations. Workers adding bleach to process vats or operating bleaching equipment need acid gas protection specifically for chlorine/HCl. If the bleaching process also involves organic process chemicals, the 60923's combined OV+acid gas+P100 profile covers both aspects.
Acid Etching and Metal Preparation
Metal surface preparation before coating often involves acid etching: phosphoric acid wash (generates phosphoric acid vapor), hydrochloric acid pickling (generates HCl), or electrochemical surface treatment with acid solutions. Workers performing these processes, or in the vicinity of open acid tanks, need acid gas protection. When solvent-based cleaners or primers are used in the same operation, the 60923 covers both the solvent vapor and acid gas components.
Pulp and Paper Mills
Kraft pulp mills generate complex chemical environments: chlorine dioxide (ClO2) and chlorine (Cl2) in the bleach plant, SO2 in pulp washing and recovery, sulfur compounds throughout the cooking process, and organic vapors from pitch and turpentine. The bleach plant operations specifically require acid gas protection that the 60923 provides. The combined OV+acid gas+P100 profile covers the primary inhalation hazards during routine operations in most mill areas.
General Chemical Manufacturing
Any process involving chlorinated organic synthesis can generate HCl as a reaction byproduct alongside the primary organic compound. The 60923 ensures that HCl byproduct is captured alongside the organic vapor from the primary synthesis chemical, providing complete protection without requiring workers to identify and separately address each individual chemical in a complex reaction mixture.
OSHA Selection Requirements: Matching Cartridge to Hazard Assessment
Under 29 CFR 1910.134(d)(1)(iii), the employer must identify and evaluate the respiratory hazard in the workplace as part of the written respiratory protection program. For environments where acid gases are identified through SDS review or air monitoring, the written program must specify an acid-gas-rated cartridge. Specifying the 60921 (OV only) in a program where acid gases are documented would be a deficiency in the written program and potentially a citation under 1910.134(d)(1).
Conversely, using the 60923 in environments with only OV and particulate hazards — no acid gases — is not a compliance violation but is an unnecessary cost and may provide slightly higher breathing resistance than needed. Match the cartridge to the actual hazard profile.
For overall respirator program guidance, explore the half mask respirators collection, 3M respirator cartridges and filters, and the best half face respirator guide. For NIOSH certification context, see the NIOSH standards guide.
Frequently Asked Questions
What is the difference between the 60923 and the 60921?The 60921 provides organic vapor + P100 protection. The 60923 adds acid gas protection (chlorine, HCl, SO2, H2S at low concentrations) to that profile. Use the 60923 whenever your hazard assessment identifies acid gases alongside organic vapors. The 60921 is appropriate for pure OV+particulate environments only — it provides zero acid gas protection.
The 60921 provides organic vapor + P100 protection. The 60923 adds acid gas protection (chlorine, HCl, SO2, H2S at low concentrations) to that profile. Use the 60923 whenever your hazard assessment identifies acid gases alongside organic vapors. The 60921 is appropriate for pure OV+particulate environments only — it provides zero acid gas protection.
What is the difference between the 60923 and the 60922?Both provide OV + acid gas + P100 protection. The primary difference is form factor and potentially different facepiece compatibility. Verify 3M's current compatibility chart for your specific respirator model to determine which fits. The protection profile is equivalent when both are compatible with your facepiece. See the 60922 review for detailed comparison.
Both provide OV + acid gas + P100 protection. The primary difference is form factor and potentially different facepiece compatibility. Verify 3M's current compatibility chart for your specific respirator model to determine which fits. The protection profile is equivalent when both are compatible with your facepiece. See the 60922 review for detailed comparison.
Does the 60923 protect against hydrofluoric acid (HF)?HF is listed as a protected acid gas for the 60923's acid gas component. However, HF is an extraordinarily hazardous substance — skin contact with HF can be fatal even at small quantities due to systemic fluoride toxicity. For HF environments, additional protective measures beyond respiratory protection are critical. Verify the 60923's suitability for your specific HF concentration with 3M's application engineering, and ensure comprehensive skin and eye protection are in place alongside the respiratory component.
HF is listed as a protected acid gas for the 60923's acid gas component. However, HF is an extraordinarily hazardous substance — skin contact with HF can be fatal even at small quantities due to systemic fluoride toxicity. For HF environments, additional protective measures beyond respiratory protection are critical. Verify the 60923's suitability for your specific HF concentration with 3M's application engineering, and ensure comprehensive skin and eye protection are in place alongside the respiratory component.
Is the 60923 appropriate for use in a paint booth with acid-wash primers?Yes — the combination of OV (for paint solvents), acid gas (for acid-wash/etching primer chemistry), and P100 (for paint mist) makes the 60923 well-suited for auto body operations that include acid etching steps. Workers who perform both standard solvent-based painting and acid etching primer application can use the 60923 throughout their shift without switching cartridges.
Yes — the combination of OV (for paint solvents), acid gas (for acid-wash/etching primer chemistry), and P100 (for paint mist) makes the 60923 well-suited for auto body operations that include acid etching steps. Workers who perform both standard solvent-based painting and acid etching primer application can use the 60923 throughout their shift without switching cartridges.
Can I use the 60923 for welding in environments with acid-based flux?Potentially yes. Acid-based flux used in brazing and soldering releases HF, HCl, or other acid gas species during heating, depending on flux chemistry. If welding or brazing also generates metallic fume (P100 hazard) and the flux is acid-based (acid gas hazard), the 60923 covers all three components. Review the SDS for your specific flux product to verify the acid gas species generated.
Potentially yes. Acid-based flux used in brazing and soldering releases HF, HCl, or other acid gas species during heating, depending on flux chemistry. If welding or brazing also generates metallic fume (P100 hazard) and the flux is acid-based (acid gas hazard), the 60923 covers all three components. Review the SDS for your specific flux product to verify the acid gas species generated.
How long does the acid gas sorbent in the 60923 last?Acid gas sorbent service life depends on the specific acid gas, its concentration, temperature, and relative humidity. 3M's service life data for the acid gas component should be consulted for your specific application. In general, the acid gas sorbent exhausts more quickly in high-concentration acid gas environments than the OV carbon does in typical solvent environments. Develop a conservative change schedule and document it in your written respiratory protection program.
Acid gas sorbent service life depends on the specific acid gas, its concentration, temperature, and relative humidity. 3M's service life data for the acid gas component should be consulted for your specific application. In general, the acid gas sorbent exhausts more quickly in high-concentration acid gas environments than the OV carbon does in typical solvent environments. Develop a conservative change schedule and document it in your written respiratory protection program.
Does the 60923 protect against sulfuric acid mist?Sulfuric acid mist is both an acid gas (SO2 generated from SO3/H2SO4 vapors) and an aerosol (fine droplets of H2SO4). The P100 component captures the aerosol mist; the acid gas component provides some protection against the vapor phase. For strong sulfuric acid environments (battery rooms, acid plants), verify with 3M's technical resources that the 60923 is appropriate for your specific sulfuric acid concentration and form (vapor, mist, or both).
Sulfuric acid mist is both an acid gas (SO2 generated from SO3/H2SO4 vapors) and an aerosol (fine droplets of H2SO4). The P100 component captures the aerosol mist; the acid gas component provides some protection against the vapor phase. For strong sulfuric acid environments (battery rooms, acid plants), verify with 3M's technical resources that the 60923 is appropriate for your specific sulfuric acid concentration and form (vapor, mist, or both).
Is the 60923 the right choice for chemical plant turnaround maintenance?For turnaround maintenance in chemical plants handling acid-gas-producing chemicals (HCl, SO2, Cl2) alongside organic solvents and with potential particulate from scale, rust, and process deposits, the 60923 is a strong candidate for "general-purpose" turnaround respiratory protection. However, a qualified industrial hygienist should review the specific chemicals present at each unit to confirm the 60923 covers all identified hazards — some specialized chemicals may require additional or different cartridge chemistry.
For turnaround maintenance in chemical plants handling acid-gas-producing chemicals (HCl, SO2, Cl2) alongside organic solvents and with potential particulate from scale, rust, and process deposits, the 60923 is a strong candidate for "general-purpose" turnaround respiratory protection. However, a qualified industrial hygienist should review the specific chemicals present at each unit to confirm the 60923 covers all identified hazards — some specialized chemicals may require additional or different cartridge chemistry.
Can Honeywell North cartridges be substituted for the 60923?Honeywell North makes equivalent acid gas combination cartridges for their respirator platform — but 3M and Honeywell cartridges are NOT interchangeable. Each brand's cartridges fit only their own facepieces. Browse the Honeywell North respirator cartridges and the Honeywell North cartridge guide for Honeywell equivalents.
Honeywell North makes equivalent acid gas combination cartridges for their respirator platform — but 3M and Honeywell cartridges are NOT interchangeable. Each brand's cartridges fit only their own facepieces. Browse the Honeywell North respirator cartridges and the Honeywell North cartridge guide for Honeywell equivalents.
Does the 60923 protect against carbon dioxide (CO2)?No. CO2 is not an acid gas in the context of NIOSH respirator cartridge classifications, nor is it an organic vapor. CO2 is an asphyxiant — it displaces oxygen. Air-purifying respirators of any type, including the 60923, are not appropriate for CO2-rich environments. Oxygen-deficient or CO2-enriched atmospheres (below 19.5% O2) require supplied-air or SCBA.
No. CO2 is not an acid gas in the context of NIOSH respirator cartridge classifications, nor is it an organic vapor. CO2 is an asphyxiant — it displaces oxygen. Air-purifying respirators of any type, including the 60923, are not appropriate for CO2-rich environments. Oxygen-deficient or CO2-enriched atmospheres (below 19.5% O2) require supplied-air or SCBA.
What is the maximum use concentration for the 60923?With an APF of 10 (half-mask APR), maximum use concentration = 10× OSHA PEL for each specific chemical. For chlorine (PEL 1 ppm ceiling), maximum use concentration is 10 ppm — but the IDLH is also 10 ppm, so this is at the IDLH boundary. For HCl (PEL 5 ppm ceiling), maximum is 50 ppm but IDLH is 50 ppm — again at the boundary. For SO2 (PEL 5 ppm), maximum is 50 ppm; IDLH is 100 ppm. At or above IDLH concentrations for any chemical, a supplied-air respirator is required.
With an APF of 10 (half-mask APR), maximum use concentration = 10× OSHA PEL for each specific chemical. For chlorine (PEL 1 ppm ceiling), maximum use concentration is 10 ppm — but the IDLH is also 10 ppm, so this is at the IDLH boundary. For HCl (PEL 5 ppm ceiling), maximum is 50 ppm but IDLH is 50 ppm — again at the boundary. For SO2 (PEL 5 ppm), maximum is 50 ppm; IDLH is 100 ppm. At or above IDLH concentrations for any chemical, a supplied-air respirator is required.
Where can I buy the 3M 60923?The 3M 60923 cartridges are available through WCSafety in the 3M respirator cartridges and filters collection. Contact WCSafety for bulk pricing for industrial programs requiring case quantities.
The 3M 60923 cartridges are available through WCSafety in the 3M respirator cartridges and filters collection. Contact WCSafety for bulk pricing for industrial programs requiring case quantities.
Does the 60923 require a written change schedule?Yes — OSHA 29 CFR 1910.134(d)(3)(iii) requires a written change schedule for air-purifying respirator cartridges with sorbent beds. Both the OV and acid gas components of the 60923 require documented change schedules based on 3M's service life data and your specific exposure concentrations from air monitoring. Document this in your written respiratory protection program.
Yes — OSHA 29 CFR 1910.134(d)(3)(iii) requires a written change schedule for air-purifying respirator cartridges with sorbent beds. Both the OV and acid gas components of the 60923 require documented change schedules based on 3M's service life data and your specific exposure concentrations from air monitoring. Document this in your written respiratory protection program.
Can I extend 60923 cartridge life by storing them in a sealed bag?Yes — sealing cartridges between uses significantly extends service life by preventing ambient air from consuming sorbent capacity while not in use. Store in a zip-lock bag or the cartridge's storage bag. This is standard practice and should be specified in your respiratory protection program procedures. See how to properly clean and maintain a respirator for complete care protocols.
Yes — sealing cartridges between uses significantly extends service life by preventing ambient air from consuming sorbent capacity while not in use. Store in a zip-lock bag or the cartridge's storage bag. This is standard practice and should be specified in your respiratory protection program procedures. See how to properly clean and maintain a respirator for complete care protocols.
What full-face option provides higher protection with acid gas coverage?For environments requiring APF 50 (full-face) with acid gas protection, see 3M's full-face compatible cartridges in the full-face respirators collection and the 3M full-face respirator guide. Full-face respirators provide 5× the protection factor of half-masks and also protect against eye/face splash from acid gases — a critical additional benefit in acid environments.
For environments requiring APF 50 (full-face) with acid gas protection, see 3M's full-face compatible cartridges in the full-face respirators collection and the 3M full-face respirator guide. Full-face respirators provide 5× the protection factor of half-masks and also protect against eye/face splash from acid gases — a critical additional benefit in acid environments.