The Cartridge,respirator,air Filteri, cataloged under National Stock Number 4240-01-248-0381, is classified within Federal Supply Class 4240 (Safety and Rescue Equipment) of the Fire Fighting, Rescue, and Safety Equipment group. The manufacturer of record is Square D Co Monroe Plant. Government technical data includes 3 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4240-01-248-0381 |
| Primary Part Number | R51AP |
| Item Name | Cartridge,respirator,air Filteri |
| FSC / FSG | 4240 / 42 — Safety and Rescue Equipment |
| Manufacturer | Square D Co Monroe Plant |
| Status | ACTIVE |
| FSC Application Data | RESPIRATOR,AIR FILTERING |
| Hazard Protection Feature | PAINT MIST AND DUST AND MIST AND ORGANIC VAPORS,LACQUERS AND ENAMELS |
| Criticality Code Justification | FEAT |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | Y |
| Part Number | Manufacturer |
|---|---|
| R51AP PRIMARY | Square D Co Monroe Plant (USA) |
| Reference | Meaning |
|---|---|
| R51AP | 5/9 Secondary reference American Optical Co |
NSN 4240-01-248-0381 is a Cartridge,respirator,air Filteri, manufactured by Square D Co Monroe Plant, classified under FSC 4240, Safety and Rescue Equipment. Status: active.
NSN 4240-01-248-0381 has 1 manufacturer part number on file: R51AP (Square D Co Monroe Plant).
Key specifications for R51AP: FSC Application Data: RESPIRATOR,AIR FILTERING; Hazard Protection Feature: PAINT MIST AND DUST AND MIST AND ORGANIC VAPORS,LACQUERS AND ENAMELS; Criticality Code Justification: FEAT; Special Features: SOLE SOURCE REQUIRED BY STATUTE 6.302; USED ON AMERICAN OPTICAL MODELS S/R4500,S/R5500,S/R6500,S/R7700,S/R4000,S/R5000,S/R6000 AND S/R7000 RESPIRATORS. 3 specifications are documented in the U.S. Government catalog.
Possible hazard — SDS may be required (DLA HMIC P). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.