UN 1384 — Sodium hydrosulphite
Placard: Spontaneously Combustible. ERG Guide 135. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1384 is Sodium hydrosulphite, a spontaneously combustible reducing solid assigned to ERG Guide 135. Moisture and heat can trigger decomposition, sulfur dioxide release and self-heating.
Hazard overview: UN 1384 presents self-heating, moisture-reactive and sulfur dioxide fume hazards. Bulk material should be kept dry, and responders should avoid water or foam directly on the product unless command confirms compatibility.
Response guidance: For a UN 1384 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 135. Establish incident command, isolate the area, stay upwind, avoid unnecessary disturbance of powder, piles or damaged packaging, and use only extinguishing agents compatible with the specific material.
Firefighter training notes: Training for UN 1384 should emphasize dangerous-when-wet behavior, reaction gas identification, dry-agent selection and downwind gas control. Common errors include using water or foam directly, entering low areas without monitoring and underestimating re-ignition. Use ERG 135, SDS and hazmat SOP.
Regulatory context: Sodium hydrosulphite is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, waste handling, storage and environmental requirements may vary by formulation, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Sodium hydrosulphite should be stored in tightly closed compatible containers in a cool, dry, well-ventilated area away from water, moisture, acids, oxidizers, heat and ignition sources. Protect containers from damage and keep compatible dry spill-control media available where required.
UN 1384 Quick Details
Common Hazards of UN 1384
- SPONTANEOUSLY COMBUSTIBLE reducing solid; moisture can generate heat and sulfur dioxide.
- May self-heat, decompose or ignite when damp, contaminated or exposed to humid air.
- Reaction with water may generate heat and pressure.
- May be ignited by heat, sparks or flames and may re-ignite after apparent extinguishment.
- Containers may rupture or explode when heated.
- Runoff or water application may spread contamination and increase gas generation.
- Avoid low, enclosed or poorly ventilated areas where reaction gases may accumulate.
Chemical Identity & Physical Properties
White to grayish-white crystalline powder or granular solid. Odorless or slight sulfurous odor. Hygroscopic material that may become damp or caked on exposure to moist air.
| Also known as | Sodium dithioniteSodium hydrosulfiteSodium sulfoxylateVatroliteHydros |
| CAS Number | 7775-14-6 |
| Appearance | White to grayish-white crystalline powder or granular solid. Odorless or slight sulfurous odor. Hygroscopic material that may become damp or caked on exposure to moist air. |
| Flash Point | Not applicable (spontaneously combustible solid) |
| Boiling Point | Not applicable (decomposes at approximately 52C/126F) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Reacts with water generating heat and sulfur dioxide gas. May ignite spontaneously when wet or exposed to moisture. |
Fireground Response Guidance — UN 1384
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for any suspected sulfur dioxide and heat, fire, vapor or confined-space exposure. Chemical-resistant clothing, gloves and eye/face protection should be selected from SDS and incident command; air monitoring is important.
Isolation & Evacuation
First Actions for a UN 1384 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Avoid low areas where sulfur dioxide and heat may collect.
- Do not touch spilled material or damaged containers unless properly trained and equipped.
- Keep water, foam and moisture away from the released material unless incident command confirms a compatible cooling or control use.
- Ventilate closed spaces before entering, but only if properly trained, equipped, monitored and authorized by incident command.
- Isolate the spill or leak area and expand the perimeter if water contact, fire or gas generation is suspected.
- Use ERG Guide 135, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1384 — Sodium hydrosulphiteUse for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.