The Mask,air Line, cataloged under National Stock Number 4240-01-104-5204, 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 Mine Safety Appliances Company. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4240-01-104-5204 |
| Primary Part Number | 475218 |
| Item Name | Mask,air Line |
| FSC / FSG | 4240 / 42 — Safety and Rescue Equipment |
| Manufacturer | Mine Safety Appliances Company |
| 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 |
| Part Number | Manufacturer |
|---|---|
| 475218 PRIMARY | Mine Safety Appliances Company (USA) |
| Reference | Meaning |
|---|---|
| 461699 | 5/9 Secondary reference Mine Safety Appliances Company |
| 1960 | 5/9 Secondary reference Survivair Corp Sub of Comasec Inc |
| 475217 | 5/9 Secondary reference Mine Safety Appliances Company |
| 1960 | 5/9 Secondary reference Dalloz Safety |
NSN 4240-01-104-5204 is a Mask,air Line, manufactured by Mine Safety Appliances Company, classified under FSC 4240, Safety and Rescue Equipment. Status: active.
NSN 4240-01-104-5204 has 1 manufacturer part number on file: 475218 (Mine Safety Appliances Company).
Key specifications for 475218: Special Features: DESIGNED TO MAINTAIN A SLIGHT POSITIVE PRESSURE OF AIR INSIDE THE FACEPIECE WHEN INHALING OR EXHALING; PRESSURE DEMAND AIR-LINE W/ULTRAVUE FACEPEICE; BREATHING TUBE; REGULATOR W/QUICK-DISCONNECT; AND WEB BELT. 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.