The Mask,chemical-Biological, cataloged under National Stock Number 4240-00-987-9588, is classified within Federal Supply Class 4240 (Safety and Rescue Equipment) of the Fire Fighting, Rescue, and Safety Equipment group. Government technical data includes 22 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4240-00-987-9588 |
| Item Name | Mask,chemical-Biological |
| FSC / FSG | 4240 / 42 — Safety and Rescue Equipment |
| Status | ACTIVE |
| Carrier Position Type | ONE POSITION |
| Hose Quantity | 1 |
| Filter Type | CANISTER |
| Quantity | 1 |
| Microphone | INCLUDED |
| Spectacle Usage Provision | NOT PROVIDED |
| Canister to Facepiece Attachment Method | HOSE |
| Carrying Facility | CARRIER |
| Accessory Components and Quantity | ANTIFOGGING KIT 1 |
| Facepiece Speaking Diaphragm | NOT INCLUDED |
| Carrying Position for Which Designed | LEFT SIDE |
| Quick Disconnect Coupling Feature | INCLUDED |
| Size Designation | SMALL |
| Canister Carrying Harness | INCLUDED |
| Face Cover Type | FACEPIECE |
| Protection for Which Filter Is Designed | BIOLOGICAL ORGANISMS AND CHEMICAL RESISTANT |
| Material | PLASTIC LENS |
| Material | RUBBER POLYISOPRENE NATURAL CLASS NR LOCATION NOT OTHERWISE SPECIFIED |
| Canister Manufacturer Symbol | NONE |
| Particulate Filter | INCLUDED |
| User Designator | COMBAT VEHICLE CREWMAN |
| Carrier Wearing Position | LEFT SIDE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL F — Mutilate — Cut |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | N |
| Reference | Meaning |
|---|---|
| C5-1-315SMALL | 3/1 Design control — primary reference U.S. Government activity |
NSN 4240-00-987-9588 is a Mask,chemical-Biological, classified under FSC 4240, Safety and Rescue Equipment. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4240-00-994-8751. Verify interchangeability with system specifications before substitution.
Key specifications for 4240-00-987-9588: Carrier Position Type: ONE POSITION; Hose Quantity: 1; Filter Type: CANISTER; Quantity: 1. 22 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.
NSN 4240-00-987-9588 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.