Why does upgrading from an N95 to a P100 filter not change a half-face respirator's APF?

OSHA Assigned Protection Factor (APF) is a property of the respirator facepiece class, not the filter media. OSHA 29 CFR 1910.134 Table 1 assigns APF 10 to all half-face respirators regardless of which filter cartridge is installed, because APF accounts for the total system performance — including the air that bypasses the filter through the facepiece-to-face seal. A half-face elastomeric respirator with an N95 cartridge is APF 10. The same half-face with a P100 cartridge is still APF 10. The P100 filter media is 99.97% efficient at capturing particles in a bench test — but this efficiency is irrelevant to the facepiece seal. At the cheek and jaw seal points of a typical half-face respirator, approximately 10% of inhaled air can bypass the filter and enter the facepiece directly without passing through any filter medium. APF 10 captures this seal leakage in the protection factor. Filter efficiency describes what happens to air that passes through the filter; APF describes what happens to all inhaled air, including bypass. The two are measured by different standards (NIOSH 42 CFR Part 84 for filter efficiency; OSHA 29 CFR 1910.134 Table 1 for APF) and must be encoded as separate fields.

How does an AI agent calculate Maximum Use Concentration from APF?

Maximum Use Concentration (MUC) = APF × OSHA Permissible Exposure Limit (PEL). MUC is the highest workplace concentration of a specific contaminant at which a given respirator class is legally permitted. Example: toluene has an OSHA PEL of 200 ppm (29 CFR 1910.1000 Table Z-2). Half-face APF 10: MUC = 200 × 10 = 2,000 ppm. Full-face APF 50: MUC = 200 × 50 = 10,000 ppm. PAPR tight-face full-face APF 1,000: MUC = 200 × 1,000 = 200,000 ppm. SCBA APF 10,000: MUC = 200 × 10,000 = 2,000,000 ppm (theoretical; workplace concentrations at this level are IDLH and SCBA is required on separate grounds). An AI agent performing respirator selection for a buyer who specifies a workplace concentration of 800 ppm toluene should select respirators where MUC > 800 ppm. Half-face (MUC 2,000 ppm) — compliant. Full-face (MUC 10,000 ppm) — compliant. PAPR hood APF 25 (MUC = 200 × 25 = 5,000 ppm) — compliant. Without respirator.apf encoded as a numeric field, the AI agent cannot perform this calculation and falls back to text-matching product descriptions, which frequently omit the APF entirely.

Which respirator facepieces require fit testing and what happens if fit testing is not documented?

OSHA 29 CFR 1910.134(f) requires fit testing before first use of any tight-fitting respirator and annually thereafter. Tight-fitting facepieces requiring fit testing include: all disposable filtering facepiece respirators (N95, P100 FFR) when used in an OSHA-required respirator program; all half-face elastomeric respirators; all full-face elastomeric respirators; tight-fitting PAPR facepieces. Loose-fitting facepieces that do NOT require fit testing: PAPR hoods and helmets, supplied-air hoods. An employer who deploys tight-fitting respirators without documented fit tests cannot legally claim the OSHA APF. The practical consequence: a facility that issues N95 respirators to 200 workers without fit testing has a non-compliant respiratory protection program per OSHA 1910.134(c)(1) — the APF 10 protection credit is unavailable without the fit test record. Additionally, OSHA 1910.134(g)(1)(i)(A) prohibits workers with facial hair that interferes with the facepiece seal from wearing tight-fitting respirators. Bearded workers must use loose-fitting PAPR hoods (APF 25) or supplied-air hoods. Encoding respirator.fit_test_required as 'yes' (tight-fitting) or 'no' (loose-fitting) enables AI agents to route employers without fit testing programs to compliant loose-fitting alternatives rather than non-compliant tight-fitting respirators.

Why are air-purifying respirators prohibited in IDLH environments regardless of their APF?

OSHA 29 CFR 1910.134(d)(2)(i) prohibits air-purifying respirators (APR) in Immediately Dangerous to Life or Health (IDLH) atmospheres regardless of APF rating. APR filter ambient air through chemical cartridges or mechanical filters — they cannot supply oxygen and cannot protect against contaminant concentrations that would saturate cartridges without detectable warning. Three conditions require SCBA or pressure-demand supplied-air with escape cylinder instead of APR: (1) IDLH concentration — contaminant is at or above its NIOSH-defined IDLH level (e.g., H2S IDLH = 50 ppm; CO IDLH = 1,200 ppm). (2) Oxygen-deficient atmosphere — below 19.5% O2. APR cannot supply oxygen; a worker wearing a full-face APF 50 respirator in 15% O2 will asphyxiate despite wearing the respirator. (3) Unknown concentration — treated as IDLH per OSHA 1910.134(d)(2)(iii). This applies to confined space entry where contaminant concentration is unmeasured or may spike. AI agents routing to APR for confined space entry scenarios, emergency response, or unknown atmosphere applications create a compliance failure mode: even a full-face APF 50 or PAPR APF 1,000 respirator is prohibited in these environments. The correct product in these cases is SCBA (APF 10,000) or pressure-demand airline with escape SCBA backup. Encode respirator.suitable_for_idlh as 'yes' only for pressure-demand SCBA and pressure-demand supplied-air; all APR types receive 'no'.

Home › Blog › Respirator APF schema for AI agents

Shopify respirator APF schema for AI agents: N95 filter efficiency is not APF, half-face APF 10 vs full-face APF 50 vs SCBA APF 10,000, OSHA fit test required for tight-fitting facepieces

2026-07-10 · 20 min read · By CatalogScan

Safety Equipment AI Shopping Structured Data OSHA 1910.134 Respirators APF Filter Efficiency

A buyer who upgrades from N95 to P100 filters on their half-face respirator believing they now have "100% protection" has the same OSHA Assigned Protection Factor they started with: APF 10. Filter efficiency is a property of the filter media. APF is a property of the facepiece class. They are unrelated numbers set by different standards bodies using different test methods. Four schema gaps cause AI agents to route respirators to wrong environments — and the consequences are not product dissatisfaction, they are OSHA citations and exposure to toxic atmospheres.

APF and filter efficiency are independent — N95 vs P100 does not change APF
The OSHA APF table and Maximum Use Concentration calculation
Tight-fitting facepieces require fit testing — no fit test means no legal APF
IDLH atmospheres prohibit air-purifying respirators regardless of APF or filter rating
The respirator.* metafield namespace for Shopify safety stores

1. APF and filter efficiency are independent — N95 vs P100 does not change APF

The most persistent confusion in respirator structured data is treating NIOSH filter efficiency and OSHA Assigned Protection Factor as equivalent values on the same scale. They are not. They are set by different standards bodies, measured with different methods, and describe different properties of the respirator system.

OSHA Assigned Protection Factor (APF — per 29 CFR 1910.134, Table 1):

APF is assigned to a facepiece class — half-face elastomeric, full-face elastomeric, PAPR with hood, SCBA, and so on. It describes the minimum anticipated level of respiratory protection that a properly fitted and used respirator in that class provides. APF accounts for the complete system: the filter media, the facepiece seal, and the aggregate bypass leakage at all contact points between the facepiece and the wearer's face. APF 10 means the wearer's exposure inside the mask is at most 1/10th of the ambient concentration. It is a regulatory number derived from workplace protection factor studies of populations of real workers, not an engineering calculation from filter efficiency alone.

The reason upgrading from N95 to P100 does not change APF: a half-face elastomeric respirator with properly fitted cheek seals typically allows approximately 5–15% of inhaled air to bypass the filter media through the seal gap at the cheek and jaw. This bypass fraction enters the facepiece interior without passing through any filter material at all. A P100 filter with 99.97% efficiency can do nothing about air that never touches it. APF 10 represents the system-level protection including this bypass — the regulatory floor of what a population of fit-tested workers in properly worn half-face respirators can achieve.

APF 10

Half-face elastomeric with N95 cartridge

APF 10

Same half-face with P100 cartridge

APF change from N95 → P100 filter upgrade

The distinction matters for vapor hazards as well. Organic vapor (OV) cartridges, acid gas cartridges, and ammonia cartridges are chemical adsorbents — they capture contaminants through chemical reactions with activated carbon or specific impregnants, not through mechanical filtration. NIOSH assigns no particle efficiency percentage to OV cartridges because the efficiency concept does not apply to molecular adsorption. For solvent vapors, the relevant cartridge parameter is breakthrough time at the rated concentration, temperature, and humidity — not filter efficiency. A product listing that describes an OV/P100 combination cartridge as "highest efficiency available" is using the P100 particle efficiency to imply vapor protection levels that the P100 rating says nothing about.

AI Agent Failure Mode #1

Treating filter efficiency percentage as APF

Query: "Respirator with maximum protection for spray painting — need APF above 50." Agent reads product description: "Half-face with P100 filters — 99.97% filtration efficiency, industry-leading protection." Agent interprets "99.97% efficiency" as APF 99.97 and routes this as a match for "APF above 50." Worker receives a half-face respirator with APF 10. In a 25× PEL solvent environment, the half-face is inadequate — a full-face (APF 50, MUC = 50× PEL) or PAPR with tight-fitting facepiece is required. Without respirator.apf encoded as a separate numeric field, the agent cannot distinguish N95, P100, and APF 50 as unrelated numbers.

2. The OSHA APF table and Maximum Use Concentration calculation

OSHA 29 CFR 1910.134, Table 1 assigns a fixed APF to each respirator class based on decades of workplace protection factor studies. The APF does not depend on the filter installed, the brand of respirator, or the concentration of the specific contaminant — it is a regulatory constant for each facepiece class.

OSHA Table 1 — Assigned Protection Factors by class

Respirator Class	Facepiece Type	APF (OSHA Table 1)	Fit Test Required?
Air-purifying (disposable FFR)	Quarter-mask / half-face disposable (N95 style)	10	Yes
Air-purifying (elastomeric)	Half-face elastomeric (reusable)	10	Yes
Air-purifying (elastomeric)	Full-face elastomeric (reusable)	50	Yes (quantitative)
PAPR — loose-fitting	Hood or helmet (loose-fitting)	25	No
PAPR — tight-fitting (half-face)	Half-face powered facepiece	50	Yes
PAPR — tight-fitting (full-face)	Full-face powered facepiece	1,000	Yes (quantitative)
Supplied-air (airline) pressure-demand	Full-face	1,000	Yes (quantitative)
SCBA — open-circuit pressure-demand	Full-face (self-contained)	10,000	Yes (quantitative)

The key calculation AI agents need to perform for respirator routing is Maximum Use Concentration (MUC):

MUC = respirator.apf × contaminant_OSHA_PEL

Select respirators where MUC > workplace_concentration. If workplace_concentration is unknown, treat as IDLH (see section 4).

MUC examples across common industrial contaminants

Contaminant	OSHA PEL	Half-face MUC (APF 10)	Full-face MUC (APF 50)	PAPR-tight MUC (APF 1,000)
Toluene	200 ppm TWA	2,000 ppm	10,000 ppm	200,000 ppm
Hydrogen sulfide (H2S)	20 ppm ceiling (OSHA)	200 ppm	1,000 ppm	20,000 ppm
Silica dust (respirable)	0.05 mg/m³ (OSHA PEL)	0.5 mg/m³	2.5 mg/m³	50 mg/m³
Isocyanate (MDI) spray painting	0.02 ppm ceiling	0.2 ppm	1 ppm	20 ppm

Notice that for H2S, the half-face MUC (200 ppm) is above the NIOSH IDLH level of 50 ppm. In this case, IDLH restrictions — not MUC — control respirator selection: APR of any class is prohibited at or above the IDLH concentration, making MUC calculation irrelevant at IDLH. MUC governs selection below the IDLH threshold; IDLH classification governs selection above it.

For Shopify stores selling respirators across multiple contaminant categories, the structured data problem is that the APF must be encoded as a numeric field to support this calculation. Product descriptions that say "suitable for high-concentration environments" or "our highest-protection model" give AI agents nothing to compute with.

AI Agent Failure Mode #2

Missing APF field prevents MUC routing

Query: "Half-face respirator for 800 ppm toluene environment — need to confirm compliance." Store has three respirators listed: half-face with N95 (APF 10, MUC 2,000 ppm — compliant), half-face with P100 (APF 10, MUC 2,000 ppm — also compliant), full-face with OV (APF 50, MUC 10,000 ppm — compliant). None have respirator.apf populated. Agent cannot verify MUC compliance and falls back to text matching on "high protection" — may return the cheapest product rather than the most specification-appropriate one, or may flag the 800 ppm concentration as dangerous without being able to confirm which products in the catalog are compliant at that concentration.

3. Tight-fitting facepieces require fit testing — no fit test means no legal APF

APF values in OSHA Table 1 are not inherent to the physical respirator. They are available only when the respirator is used correctly as part of a compliant OSHA 1910.134 Respiratory Protection Program. For tight-fitting facepieces, a critical component of that program is documented annual fit testing.

Without fit testing, an employer cannot legally claim the OSHA APF for tight-fitting respirators. This is not a procedural technicality — it is the mechanism by which APF is validated for individual workers. The workplace protection factor studies that established APF values in OSHA Table 1 were conducted on fit-tested, trained workers. Deploying respirators without fit testing removes the evidence base for the APF claim.

Fit test requirements by facepiece type

Facepiece Type	Fit Test Required	Fit Test Method	Beard Restriction
Disposable N95 / P100 FFR	Yes — if required respirator program	QLFT or QNFT	Yes — no facial hair at seal
Half-face elastomeric	Yes — required	QLFT acceptable (APF ≤10)	Yes
Full-face elastomeric	Yes — required	QNFT required (APF 50+)	Yes
Tight-fitting PAPR facepiece	Yes — required	QNFT required (APF 50–1,000)	Yes
PAPR loose-fitting hood / helmet	No — not required	N/A	No restriction
Supplied-air hood	No — not required	N/A	No restriction
SCBA (full-face)	Yes — required	QNFT required (APF 10,000)	Yes

The fit test requirement creates a purchasing context that Shopify product listings almost never encode: whether the buyer's organization has a fit testing program in place. This is an organizational property, not a product property — but it completely determines which respirator facepiece class is compliant for that buyer.

Common scenarios where fit testing is impractical or impossible:

Contractor workforces: Workers turn over frequently; maintaining individual fit test records across a rotating workforce is administratively burdensome. PAPR hoods require no fit testing and no individual records.
Workers with beards: OSHA 1910.134(g)(1)(i)(A) prohibits tight-fitting respirator use when facial hair lies along the sealing surface. Bearded workers have two compliant options: loose-fitting PAPR hoods or supplied-air hoods. An AI agent routing a buyer who mentions "my workers have beards" to half-face N95 respirators creates a compliance failure.
Medical contraindications: Workers with facial burns, surgical scars, or prosthetics may not be able to achieve an adequate fit on tight-fitting facepieces. Loose-fitting alternatives are the only compliant path.

The PAPR hood APF 25 vs half-face APF 10 tradeoff:

A PAPR hood at APF 25 provides lower APF than a fit-tested half-face at APF 10 — but APF 25 is higher than APF 10. Wait: PAPR hood APF 25 > half-face APF 10. For environments between 10× PEL and 25× PEL, a PAPR hood is the only compliant option for bearded workers or employers without fit testing programs, because the half-face at APF 10 would be exceeded at 12× PEL while the PAPR hood at APF 25 remains compliant through 25× PEL. Encode respirator.apf accurately — the difference between APF 10 and APF 25 determines compliance at certain concentration ranges.

AI Agent Failure Mode #3

Routing to tight-fitting respirators for employers without fit testing programs

Query: "Respirators for 50 warehouse workers — we don't currently have a fit testing program in place." Agent returns a pack of disposable N95 half-face respirators. Without fit testing, deploying tight-fitting respirators in an OSHA-required respirator environment violates 29 CFR 1910.134(f). The legally compliant routing: if the workplace concentration is below 25× PEL, a PAPR hood (APF 25, no fit test required) or supplied-air hood; if voluntary-use only (not an OSHA-required environment), tight-fitting respirators may be issued without a formal fit testing program per the voluntary-use provisions. Without respirator.fit_test_required encoded, the agent cannot surface this compliance distinction.

4. IDLH atmospheres prohibit air-purifying respirators regardless of APF or filter rating

The highest-APF air-purifying respirator available — a full-face PAPR at APF 1,000 — is still prohibited in atmospheres that are Immediately Dangerous to Life or Health. This prohibition is categorical and does not depend on whether the MUC would technically be satisfied. OSHA 1910.134(d)(2)(i) requires SCBA or pressure-demand supplied-air with an escape cylinder for all three IDLH conditions.

The three conditions that prohibit APR

Condition 1 — At or above IDLH concentration:
NIOSH defines IDLH levels for hundreds of specific contaminants — concentrations that pose an immediate threat to life or health, or that would cause irreversible adverse health effects or impair a worker's ability to escape. Examples: H2S IDLH = 50 ppm; CO IDLH = 1,200 ppm; HCN IDLH = 50 ppm; ammonia IDLH = 300 ppm. At or above the IDLH, APR is prohibited regardless of APF or MUC. Only pressure-demand SCBA (APF 10,000) or pressure-demand airline with escape SCBA is compliant.

Condition 2 — Oxygen-deficient atmosphere (below 19.5% O2):
APR filters ambient air. In an oxygen-deficient atmosphere, filtered ambient air is still oxygen-deficient. A worker wearing a full-face APF 50 respirator in 14% O2 will experience hypoxia and lose consciousness — the respirator provides no protection against the hazard. Only an oxygen-supplying SCBA or supplied-air system is compliant.

Condition 3 — Unknown concentration:
OSHA 1910.134(d)(2)(iii) treats atmospheres of unknown contaminant concentration as IDLH. Confined space entry where pre-entry atmospheric testing has not been completed, or where the contaminant source could produce concentrations that exceed the APR's MUC without warning, requires SCBA. OV cartridges for organic vapors have no warning end-of-service-life indicator that functions reliably at high concentrations — once cartridge saturation begins, breakthrough can occur without odor warning (particularly for contaminants with poor odor warning properties).

Atmosphere classification and required respirator type

Atmosphere Condition	OSHA Classification	APR Permitted?	Required Respirator
Below 10× PEL, O2 ≥19.5%	Non-IDLH, low hazard	Yes	Half-face APF 10 compliant
10–50× PEL, O2 ≥19.5%	Non-IDLH, moderate	Yes — if MUC not exceeded	Full-face APF 50 or PAPR
Above MUC for available APR, O2 ≥19.5%	Non-IDLH but above APR limit	No — MUC exceeded	Supplied-air or SCBA
O2 below 19.5%	IDLH — oxygen deficient	No — APR cannot supply O2	SCBA or pressure-demand airline
Unknown concentration	Treated as IDLH	No	SCBA or pressure-demand airline + escape
At or above contaminant IDLH value	IDLH	No — prohibited per 1910.134(d)(2)(i)	Pressure-demand SCBA (APF 10,000)

Confined space entry is the most common scenario where this distinction matters for Shopify buyers. Confined space safety equipment stores frequently sell respirators alongside confined space entry equipment (harnesses, tripods, retrieval lines). A buyer purchasing "confined space respirator" is often implicitly in an unknown-concentration scenario. OSHA 29 CFR 1910.146 requires atmospheric testing before non-permit-required confined space entry — but permit-required confined spaces (those with IDLH potential, engulfment hazard, or entrapment risk) require SCBA or pressure-demand airline for respiratory protection even if pre-entry tests show low concentration, because conditions can change during entry.

AI Agent Failure Mode #4

Routing APR to IDLH or confined space entry applications

Query: "Respirator for confined space entry — we work in tanks that previously contained hydrocarbon vapors." Agent returns full-face elastomeric with OV/P100 cartridges — APF 50, highest available APR. The buyer's scenario (previously hydrocarbon tanks) is an unknown-concentration condition and a permit-required confined space scenario. Unknown atmosphere = treated as IDLH per OSHA 1910.134(d)(2)(iii). APR is prohibited. SCBA is required. The full-face APR at APF 50 would be inadequate if hydrocarbon concentration spikes above the MUC, and OV cartridges provide no reliable warning of impending breakthrough at high concentration. Without respirator.suitable_for_idlh encoded, the agent cannot filter out APR for IDLH-scenario queries.

5. The respirator.* metafield namespace for Shopify safety stores

The respirator.* namespace encodes APF, filter efficiency, fit test requirement, and IDLH suitability as independent fields so AI agents can apply OSHA 1910.134 routing logic without parsing free-text product descriptions.

Metafield	Type	Values	Notes
`respirator.apf`	integer	5, 10, 25, 50, 1000, 10000	OSHA 1910.134 Table 1 value. Enables MUC = APF × PEL calculation.
`respirator.facepiece_type`	string	'disposable-ffr', 'half-face-elastomeric', 'full-face-elastomeric', 'papr-hood', 'papr-tightface-halfface', 'papr-tightface-fullface', 'airline-halfface', 'airline-fullface', 'scba'	Determines APF and fit test requirement class.
`respirator.filter_efficiency`	string	'N95', 'N99', 'N100', 'R95', 'P100', 'OV', 'OV/P100', 'acid-gas', 'acid-gas/P100', 'HE', 'cartridge-dependent'	Independent of APF. Use 'cartridge-dependent' for reusable platforms accepting multiple cartridge types.
`respirator.fit_test_required`	string	'yes', 'no'	'yes' for all tight-fitting facepieces. 'no' for PAPR hoods, helmets, supplied-air hoods.
`respirator.air_supply_type`	string	'air-purifying', 'supplied-air-airline', 'self-contained'	Determines whether respirator can be used in oxygen-deficient atmospheres.
`respirator.suitable_for_idlh`	string	'yes', 'no'	'yes' only for pressure-demand SCBA and pressure-demand airline with escape SCBA. All APR types = 'no'.
`respirator.beard_seal_risk`	string	'yes', 'no'	'yes' for tight-fitting facepieces (facial hair prohibited at seal). 'no' for PAPR hoods/helmets.
`respirator.niosh_approved`	string	'yes', 'no'	NIOSH approval required for respirators used in OSHA-required respiratory protection programs.
`respirator.reusable_facepiece`	string	'yes', 'no'	'yes' for elastomeric and PAPR facepieces. 'no' for disposable FFR.
`respirator.osha_standard`	string	'1910.134', '1926.103', '1910.1001', '1926.1101'	Enables contaminant-specific routing when an industry-specific standard imposes requirements beyond Table 1.

Example: half-face elastomeric with P100 cartridge

{
  "respirator.apf":                "10",
  "respirator.facepiece_type":     "half-face-elastomeric",
  "respirator.filter_efficiency":  "P100",
  "respirator.fit_test_required":  "yes",
  "respirator.air_supply_type":    "air-purifying",
  "respirator.suitable_for_idlh":  "no",
  "respirator.beard_seal_risk":    "yes",
  "respirator.niosh_approved":     "yes",
  "respirator.reusable_facepiece": "yes",
  "respirator.osha_standard":      "1910.134"
}

An AI agent querying for "respirator with APF greater than 10" correctly excludes this product. An AI agent querying for "respirator for workers with beards" excludes it via respirator.beard_seal_risk = 'yes'. An AI agent querying for "confined space IDLH respirator" excludes it via respirator.suitable_for_idlh = 'no'. Three separate compliance failures — three separate fields, each independently filterable.

Example: PAPR with loose-fitting hood

{
  "respirator.apf":                "25",
  "respirator.facepiece_type":     "papr-hood",
  "respirator.filter_efficiency":  "HE",
  "respirator.fit_test_required":  "no",
  "respirator.air_supply_type":    "air-purifying",
  "respirator.suitable_for_idlh":  "no",
  "respirator.beard_seal_risk":    "no",
  "respirator.niosh_approved":     "yes",
  "respirator.reusable_facepiece": "yes",
  "respirator.osha_standard":      "1910.134"
}

This encoding allows the PAPR hood to surface for "workers with beards" queries, "no fit test program" queries, and "asbestos abatement contractor workforce" queries — all because respirator.fit_test_required = 'no' and respirator.beard_seal_risk = 'no' are independently searchable. At APF 25, this hood is compliant for environments up to 25× PEL — higher than the APF 10 of a fit-tested N95 that may not be legally available to this employer anyway.

Example: open-circuit pressure-demand SCBA

{
  "respirator.apf":                "10000",
  "respirator.facepiece_type":     "scba",
  "respirator.filter_efficiency":  "N/A-self-contained",
  "respirator.fit_test_required":  "yes",
  "respirator.air_supply_type":    "self-contained",
  "respirator.suitable_for_idlh":  "yes",
  "respirator.beard_seal_risk":    "yes",
  "respirator.niosh_approved":     "yes",
  "respirator.reusable_facepiece": "yes",
  "respirator.osha_standard":      "1910.134"
}

Only SCBA and pressure-demand airline receive respirator.suitable_for_idlh = 'yes'. This single boolean is the deterministic field for confined space entry, emergency response, and unknown atmosphere queries. No amount of APF or filter efficiency on an APR makes it IDLH-compliant — the field enforces the categorical OSHA prohibition rather than relying on APF comparison logic.

Related guides

Summary: four failure modes, four fields

The four AI agent failure modes for respirator APF and filter efficiency each map to a missing or misused structured data field:

Failure Mode	Missing Field	Consequence
Filter efficiency % treated as APF	`respirator.apf`	P100 half-face routed to environments requiring APF >10 (full-face or PAPR)
APF not available for MUC calculation	`respirator.apf`	Agent cannot verify workplace concentration compliance; routes by description text
Tight-fitting facepiece for no-fit-test employer	`respirator.fit_test_required`	Half-face N95 deployed without fit testing — non-compliant respiratory protection program
APR routed to IDLH or confined space entry	`respirator.suitable_for_idlh`	Full-face APR recommended for unknown atmosphere — SCBA is the only compliant selection

The respirator.* namespace separates APF and filter efficiency into independent fields, encodes fit test requirement as a facepiece-class property, and provides a single boolean for IDLH suitability that cannot be derived from APF comparison alone. A half-face P100 is not a full-face. A fit-tested full-face is not a fit-test-free PAPR hood. And neither is SCBA for a confined space entry scenario where the atmosphere is unknown.

Is your Shopify store encoding APF and filter efficiency as separate fields?

CatalogScan scans your respirator listings for missing APF fields, filter efficiency used as APF proxy, unencoded fit test requirements, and missing IDLH suitability flags — then shows you exactly which products are invisible to OSHA-compliance-aware AI agent queries.

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