The Facepiece,breathing Equipment, cataloged under National Stock Number 4240-01-506-2170, is classified within Federal Supply Class 4240 (Safety and Rescue Equipment) of the Fire Fighting, Rescue, and Safety Equipment group. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4240-01-506-2170 |
| Item Name | Facepiece,breathing Equipment |
| FSC / FSG | 4240 / 42 — Safety and Rescue Equipment |
| Status | ACTIVE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 1006-53 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4240-01-506-2170 is a Facepiece,breathing Equipment, classified under FSC 4240, Safety and Rescue Equipment. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 7021-01-600-6672, 5340-01-677-7254. Verify interchangeability with system specifications before substitution.
Key specifications for 4240-01-506-2170: Special Features: MOUTHPIECE COVER. 0 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.