UN 0135 — Mercury fulminate, wetted
Placard: Explosive 1.1A. ERG Guide 112. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 0135, Mercury fulminate wetted, is a highly sensitive primary explosive classified as Explosive 1.1A with a mass explosion hazard potential. It is typically wetted with water or alcohol to reduce sensitivity during transport and storage.
Hazard overview: UN 0135 presents a mass explosion hazard in which the entire load may detonate simultaneously, producing severe blast overpressure and fragmentation. The material is acutely sensitive to heat, shock, and friction, and becomes extremely dangerous if allowed to dry out.
Response guidance: Emergency responders should isolate a minimum of 500 meters (1,600 feet) in all directions and expand the evacuation zone to 1 mile if fire is involved. Explosive ordnance disposal authorities must be notified immediately, and no attempt should be made to approach dry material.
UN 0135 Quick Details
Common Hazards of UN 0135
- Mass explosion hazard — entire load may detonate simultaneously.
- Severe blast overpressure and fragmentation.
- Sensitive to heat, shock, and friction.
- Secondary fire and debris hazard.
Chemical Identity & Physical Properties
UN 0135 Mercury fulminate appears as a gray to tan odorless crystalline powder or solid that is stabilized for transport by wetting with water or alcohol.
| Also known as | Mercury(II) fulminateFulminate of mercuryMercuric fulminateFulminating mercury |
| CAS Number | 628-86-4 |
| Appearance | Gray to tan crystalline powder or crystals. Odorless. Solid at room temperature. Highly sensitive primary explosive typically wetted with water or alcohol for safer handling. |
| Flash Point | Not applicable (explosive solid) |
| Boiling Point | Not applicable (decomposes explosively at approximately 165-170C) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Stable when wetted; becomes extremely sensitive when dry. Water is used as desensitizing agent. |
Fireground Response Guidance — UN 0135
Extinguishing Media
PPE Requirements
Responders must wear minimum Level B protection with full protective clothing and SCBA, and only EOD-trained personnel should approach if the material is confirmed or suspected to be dry.
Isolation & Evacuation
First Actions for a UN 0135 Incident
- CALL 911. Then call emergency response telephone number on shipping paper.
- Establish large isolation zone — minimum 500 meters in all directions.
- Stage upwind, uphill; limit personnel to essential responders only.
- Request Hazmat + law enforcement + additional resources immediately.
- Do not fight fire — evacuate and isolate; let burn if no life safety risk.
- Protect exposures only if safe and directed by command.
- Consult current ERG Guide 112 and follow SOP/SOG.
📋 Copy & Share Field Card
UN 0135 — Mercury fulminate, wettedUse 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.