The Mask,chemical-Biological, cataloged under National Stock Number 4240-01-143-2017, is classified within Federal Supply Class 4240 (Safety and Rescue Equipment) of the Fire Fighting, Rescue, and Safety Equipment group. Government technical data includes 17 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4240-01-143-2017 |
| Item Name | Mask,chemical-Biological |
| FSC / FSG | 4240 / 42 — Safety and Rescue Equipment |
| Status | ACTIVE |
| Carrier Position Type | TWO POSITION |
| Filter Type | FILTER ELEMENT |
| Mask Not in Use Carrier Wearing Position | LEFT SIDE |
| Quantity | 2 |
| Microphone | NOT INCLUDED |
| Spectacle Usage Provision | NOT PROVIDED |
| Carrying Facility | CARRIER |
| Facepiece Speaking Diaphragm | INCLUDED |
| Quick Disconnect Coupling Feature | NOT INCLUDED |
| Size Designation | X-SMALL |
| Face Cover Type | FACEPIECE |
| Protection for Which Filter Is Designed | BIOLOGICAL ORGANISMS AND CHEMICAL RESISTANT |
| Filter Replaceability | REPLACEABLE |
| Material | PLASTIC LENS |
| Material | RUBBER POLYISOPRENE NATURAL CLASS NR LOCATION NOT OTHERWISE SPECIFIED |
| Particulate Filter | INCLUDED |
| Carrier Wearing Position | LEFT LEG |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL F — Mutilate — Cut |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | N |
| Reference | Meaning |
|---|---|
| E5-1-552-10 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4240-01-143-2017 is a Mask,chemical-Biological, classified under FSC 4240, Safety and Rescue Equipment. Status: active.
Key specifications for 4240-01-143-2017: Carrier Position Type: TWO POSITION; Filter Type: FILTER ELEMENT; Mask Not in Use Carrier Wearing Position: LEFT SIDE; Quantity: 2. 17 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
NSN 4240-01-143-2017 has DEMIL Code F. Demilitarization may be required before disposal or transfer to non-military entities.
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.