PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

R191Filter,respirator,air Filtering

Square D Co Monroe Plant · NSN 4240-01-250-2291 · FSC 4240 · No Item Name Available
Verified by PartsTable
NSN 4240-01-250-2291 — this item is cataloged by the U.S. Government under National Stock Number 4240-01-250-2291. Primary manufacturer part number: R191.
Features
  • Filter,respirator,air Filtering — FSC 4240
  • Hazard Protection Feature: PAINT MIST
  • FSC Application Data: RESPIRATOR,AIR FILTERING
  • Criticality Code Justification: FEAT
  • 2 verified cross-references
  • Primary manufacturer: Square D Co Monroe Plant
Applications
  • Fluid filtration and purification
  • Engine intake air cleaning
  • Hydraulic system protection
General Description

The Filter,respirator,air Filtering, cataloged under National Stock Number 4240-01-250-2291, is classified within Federal Supply Class 4240 (No Item Name Available) of the Fire Fighting, Rescue, and Safety Equipment group. The primary manufacturer of record is Square D Co Monroe Plant. Government technical data includes 3 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 4 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4240-01-250-2291
Primary Part NumberR191
Item NameFilter,respirator,air Filtering
FSC / FSG4240 / 42 — No Item Name Available
ManufacturerSquare D Co Monroe Plant
StatusACTIVE
Hazard Protection FeaturePAINT MIST
FSC Application DataRESPIRATOR,AIR FILTERING
Criticality Code JustificationFEAT
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 4
3110-00-100-0316454 INTERCHANGEABLE
Cup,tapered Roller Bearing
The Timken Corporation
5905-00-180-8384 INTERCHANGEABLE
Resistor,fixed,composition
2530-00-375-8809R191 INTERCHANGEABLE
Brake Drum
Rosco Mfg Co
5895-01-094-1712R191 INTERCHANGEABLE
Control,receiver
Donfred Inc Dba Transcience
Cross-Reference Index
Part NumberManufacturer
R191 American Optical Co (USA)
R191 PRIMARY Square D Co Monroe Plant (USA)
Related Parts
3110-00-100-0316INTERCHANGEABLE
CUP,TAPERED ROLLER BEARING
454
5905-00-180-8384INTERCHANGEABLE
RESISTOR,FIXED,COMPOSITION
2530-00-375-8809INTERCHANGEABLE
BRAKE DRUM
R191
5895-01-094-1712INTERCHANGEABLE
CONTROL,RECEIVER
R191

Frequently Asked Questions

What is NSN 4240-01-250-2291?

NSN 4240-01-250-2291 is a Filter,respirator,air Filtering, manufactured by Square D Co Monroe Plant, classified under FSC 4240 (No Item Name Available). Status: active.

What are the part numbers for NSN 4240-01-250-2291?

NSN 4240-01-250-2291 has 2 cross-referenced part numbers: R191 (American Optical Co), R191 (Square D Co Monroe Plant).

What NSN replaces 4240-01-250-2291?

There are 4 known substitutes for 4240-01-250-2291: 3110-00-100-0316, 5905-00-180-8384, 2530-00-375-8809 and 1 more. Verify interchangeability with system specifications before substitution.

What are the specifications of R191?

Key specifications for R191: Hazard Protection Feature: PAINT MIST; Special Features: SOLE SOURCE REQUIRED BY STATUTE 6.302; USED ON AMERICAN OPTICAL MODEL R8000 RESPIRATOR; FSC Application Data: RESPIRATOR,AIR FILTERING; Criticality Code Justification: FEAT. 4 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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