Respirator Cartridge Color Codes: Complete ANSI/ISEA 110 Decode Guide (2026)

What do respirator cartridge color codes mean — and how do you use them to select the right cartridge?

Short answer: Respirator cartridge color codes are standardized under ANSI/ISEA 110 and identify the hazard class each cartridge is designed to protect against. Black = organic vapors; white = acid gases; yellow = organic vapor + acid gas combination; magenta = P100 particulate (HEPA); green = ammonia. The colors are a visual shortcut, not a specification — always verify the cartridge model number against the NIOSH Certified Equipment List for the specific contaminants in your workplace before use.

Respirator Cartridge Color Codes: Complete ANSI/ISEA 110 Decode Guide (2026)

Respirator cartridge color codes exist to prevent workers from installing the wrong cartridge on a respirator and entering a hazardous atmosphere with zero protection for the specific chemical present. The ANSI/ISEA 110 standard (American National Standard for Air-Purifying Respiratory Protective Devices) establishes the color-coding system used by every major U.S. respirator manufacturer — 3M, Honeywell North, Moldex, MSA — for half-face and full-face elastomeric respirators. Understanding what the colors mean, and what they do not tell you, is a foundational element of any OSHA 29 CFR 1910.134-compliant written respiratory protection program.

This guide is written for safety managers, procurement teams, and workers who need to select, verify, and maintain respirator cartridges. It covers the full ANSI/ISEA 110 color matrix, secondary color band interpretation, the distinction between color coding and NIOSH approval, and a worked example using the 3M 6000 series facepiece and cartridge ecosystem.

Why this matters.
OSHA 29 CFR 1910.134(d)(1)(ii) requires that the employer select a NIOSH-approved respirator suitable for the chemical hazard present. A cartridge with the wrong color — or the correct color but the wrong efficiency class — provides no protection against the contaminant it is not rated for, while the respirator facepiece continues to seal, giving workers a false sense of safety. NIOSH's Certified Equipment List (CEL) is the authoritative source; color coding is a visual aid to the CEL, not a substitute for it.

Part 1 — What is ANSI/ISEA 110 and who follows it?

ANSI/ISEA 110 is the American National Standard for Air-Purifying Respiratory Protective Devices, published by the International Safety Equipment Association (ISEA). It establishes performance, testing, and labeling requirements for air-purifying respirators. The color-coding specification in ANSI/ISEA 110 is the industry-consensus standard that major U.S. manufacturers follow voluntarily; NIOSH's 42 CFR Part 84 establishes approval requirements but does not mandate specific colors on approved cartridges. In practice, U.S. manufacturers align their cartridge color schemes with ANSI/ISEA 110, so the color-to-hazard mapping is consistent across brands.

ANSI/ISEA 110 vs. the old NIOSH/MSHA color system

Before ANSI/ISEA 110 was adopted as the industry consensus standard, NIOSH and MSHA (Mine Safety and Health Administration) used a legacy color system with partially different assignments — notably, some colors that were reassigned in the current standard. If you are working with older cartridges or cartridges purchased internationally, verify the color mapping against the manufacturer's current product documentation rather than relying on legacy tables.

Part 2 — Primary cartridge color codes: the full ANSI/ISEA 110 matrix

Part 3 — Combination cartridge color bands

Combination cartridges that protect against more than one hazard class use multiple color bands. The primary hazard class occupies the main body color; secondary hazard classes appear as bands. The most common combinations:

Part 4 — What color codes do NOT tell you

Color does not indicate efficiency class within a gas cartridge

A black (OV) cartridge may be a standard service-life organic vapor cartridge or an end-of-service-life indicator (ESLI) cartridge, but the color does not distinguish between service-life grades. Similarly, a black OV cartridge rated for benzene at 0.1 ppm and one rated for nuisance OV relief at low concentrations may both be black — the color encodes the hazard class, not the capacity or the specific compounds covered.

Color does not indicate filter efficiency for particle cartridges

The particulate filter efficiency class (N95, R95, P100) is not fully encoded in color alone. N95 disc filters used with the 3M 501 retainer are white/gray; P100 filters and combination cartridges with P100 are magenta. But within the N-class, the color does not distinguish N95 (95%) from N99 (99%) from N100 (99.97%). Always verify the model number on the cartridge label against the NIOSH Certified Equipment List.

Color does not encode concentration limits or IDLH warnings

No color code indicates whether a cartridge is appropriate at the ambient concentration present. A black OV cartridge rated for benzene does not change color as it approaches saturation (unless it incorporates an ESLI). The end-of-service-life decision is governed by OSHA 1910.134(d)(3)(iii)(B) — calculated change schedule or ESLI — not by the cartridge color.

Color does not guarantee facepiece compatibility

Respirator cartridges are not universally interchangeable. 3M cartridges use a bayonet-mount that is incompatible with Honeywell North, Moldex, and MSA facepieces. Each manufacturer's cartridges are approved only for use with that manufacturer's NIOSH-approved facepieces. Using a 3M cartridge on a Honeywell North facepiece is an unapproved combination under 42 CFR Part 84 — the NIOSH approval is for the complete assembly, not the components individually.

Part 5 — Cartridge service life and change schedule requirements

OSHA's change schedule requirement (1910.134(d)(3)(iii)(B))

OSHA requires employers to change air-purifying cartridges on a schedule that ensures breakthrough never occurs — defined as the point at which the contaminant concentration behind the cartridge exceeds 1/10 of the IDLH or the TLV, whichever is more protective. For gas and vapor cartridges, OSHA requires either:

• An end-of-service-life indicator (ESLI) that provides advance warning of cartridge saturation, or
• A documented change schedule based on the employer's industrial hygiene data, contaminant concentration, work duration, and the manufacturer's service-life data

For P100 particulate filters (magenta), the change trigger is increased breathing resistance or visible damage — not a time schedule, because P100 filters capture particles mechanically and do not "saturate" in the chemical sense.

Factors that shorten gas cartridge service life

• Higher ambient concentration: Carbon capacity is fixed; higher concentration depletes it faster
• Higher relative humidity: Water vapor competes with organic molecules for activated carbon sites; high humidity can reduce OV cartridge life by 30–50%
• Higher temperature: Reduces physical adsorption, increases desorption risk at higher temperatures
• Lower boiling point of the contaminant: Volatile compounds (acetone, low-MW solvents) have shorter service lives than heavy solvents (xylene, MEK)
• Higher work rate: Higher breathing rates increase volumetric air flow through the cartridge, reducing contact time and service life

Part 6 — Brand-by-brand color coding alignment

All major U.S. manufacturers align with ANSI/ISEA 110, but the specific shades and secondary markings vary. Here is how the primary color codes map to cartridge models across the brands we stock:

Browse the full 3M Respirator Cartridges and Filters collection, Honeywell North Respirator Cartridges, and Moldex Respirator Cartridges and Filters for the full cartridge lineup with model numbers and filter class specifications.

Part 7 — How to read a cartridge label (beyond the color)

A NIOSH-approved cartridge label contains four elements that govern its use, beyond the color coding:

1. NIOSH approval number. Format: TC-XX-XXXX where XX is the filter class code (23A for gas cartridges, 84A for particulates, etc.). This number links the cartridge to its approval record on the NIOSH Certified Equipment List. Verify the TC number is current — expired or superseded approvals are not valid for new respiratory protection programs.
2. Cartridge type designation. The formal NIOSH designation (OV, AG, OV/AG, P100, OV/P100, etc.) printed on the label. This is more specific than the color code — it identifies the specific hazard classes covered and their NIOSH approval basis.
3. Manufacturer part number. The SKU that confirms the specific cartridge model. Essential for procurement and change schedule documentation. The part number, not the color, is what goes into the written respiratory protection program.
4. Warning statements. NIOSH-required warnings about the contaminants not covered, concentration limits (if applicable), and IDLH warnings. Read these — a black OV cartridge typically includes a warning that it provides no protection against carbon monoxide, hydrogen sulfide, or other IDLH-threat gases.

Part 8 — Worked example: selecting a cartridge for a spray painting operation

A safety manager at an automotive refinishing shop needs to specify cartridges for workers using half-face elastomeric respirators during polyurethane isocyanate basecoat application. The job involves two hazards: isocyanate vapor (HDI/TDI class) and the atomized spray aerosol.

1. Identify the contaminants. Isocyanate basecoats contain HDI (hexamethylene diisocyanate) — NIOSH REL 0.005 ppm ceiling; OSHA PEL 0.02 ppm ceiling. The spray aerosol contains both vapor and liquid droplets of the isocyanate formulation.
2. Determine the required filter class. Isocyanate vapor requires an OV cartridge (black). The spray aerosol requires a P100 particulate filter. Therefore the required class is OV + P100 — a combination cartridge with black body and magenta P100 band.
3. Confirm concentration is within the half-face APF (10). NIOSH REL ceiling for HDI is 0.005 ppm. Half-face APF 10 allows use up to 0.05 ppm (10 × 0.005 ppm). For spray booths with engineered ventilation, this may be adequate — confirm through air sampling. Above 0.05 ppm, a supplied-air respirator is required, not a cartridge respirator.
4. Select the cartridge model. For a 3M facepiece: 3M 60921 (OV/P100). For Honeywell North: 75SCP100L. Both are black-body with magenta P100 band. Verify the model on the NIOSH CEL before ordering.
5. Set the change schedule. Isocyanate OV cartridges do not have ESLIs. Under OSHA 1910.134(d)(3)(iii)(B), the employer must calculate the change schedule. Most automotive refinishing programs change OV cartridges after each shift or after each spray session — consult the cartridge manufacturer's service-life data for your specific isocyanate formulation and spray booth concentration.
6. Document in the written program. The written respiratory protection program must specify the cartridge model number (not just "OV/P100"), the change schedule, and the rationale. Color coding alone is insufficient documentation — OSHA inspectors review program documentation for model number specificity.

For the complete guide to 3M filter and cartridge selection by application, see the 3M Respirator Filter & Cartridge Guide (2026). For Honeywell North cartridges, see Best Honeywell North Respirator Filters and Cartridges (2026).

Frequently asked questions

Further reading on this site

• 3M Respirator Filter & Cartridge Guide (2026) — application-by-application breakdown of every 3M cartridge and filter model with job-site selection chart.
• Best Honeywell North Respirator Filters and Cartridges (2026) — complete guide to all 17 Honeywell North cartridge and filter models with hazard class mapping.
• 3M Respirator Cartridges and Filters — full lineup of 3M cartridges, combination cartridges, and particulate disc filters.
• Honeywell North Respirator Cartridges — complete Honeywell North cartridge and filter inventory for North series facepieces.
• Moldex Respirator Cartridges and Filters — Moldex cartridge lineup for 7000, 7800, and full-face series respirators.
• Half Mask Respirators — elastomeric half-face facepieces compatible with all cartridge systems above.
• What Happens If a Respirator Doesn't Fit? — the parallel protection failure: even the correct cartridge delivers zero protection if the facepiece doesn't seal.