UN 2778 — Mercury based pesticide, liquid, flammable, poisonous
Placard: Flammable. ERG Guide 131. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Mercury based pesticide, liquid, flammable, poisonous is a variable pesticide formulation shipped as a toxic flammable liquid. The active ingredient and solvent system must be verified before responders choose final tactics.
Hazard overview: Mercury based pesticide may be highly toxic by inhalation, ingestion or skin absorption. Liquid or dust contact can irritate or burn skin and eyes depending on the formulation. Fire or heating may produce irritating, toxic and corrosive decomposition products.
Response guidance: For a Mercury based pesticide, liquid, flammable, poisonous release, isolate the area, remove ignition sources if present, and keep runoff out of drains. Responders should use SCBA with chemical-resistant clothing and base tactics on SDS, shipping papers and monitoring.
Firefighter training notes: Train responders to identify the UN number, product name, placard, container type and exposure route before committing personnel to the hot zone.
Regulatory context: Use the proper DOT shipping description, ERG guide, SDS and site-specific response plan; do not substitute this summary for regulatory compliance.
Storage & handling: Store away from heat, sparks, oxidizers, drains and food/feed materials; segregate by pesticide formulation and SDS requirements.
UN 2778 Quick Details
Common Hazards of UN 2778
- Mercury based pesticide may be highly toxic by inhalation, ingestion or skin absorption.
- Liquid or dust contact can irritate or burn skin and eyes depending on the formulation.
- Fire or heating may produce irritating, toxic and corrosive decomposition products.
- Runoff, wash water and contaminated absorbent can carry pesticide into drains or waterways.
- Exact active ingredient, solvent carrier and concentration must be verified from SDS and shipping papers.
- Flammable solvent vapors may form explosive mixtures with air.
- Vapors can travel to ignition sources and flash back, especially in low or confined areas.
- Containers may rupture or explode when heated.
Chemical Identity & Physical Properties
Clear to colored liquid with characteristic pesticide odor. May range from colorless to amber or brown depending on formulation. Flammable toxic liquid at room temperature.
| Also known as | Mercury pesticide liquidMercurial pesticide solutionOrganomercury pesticide formulationAlkylmercury pesticide |
| Appearance | Clear to colored liquid with characteristic pesticide odor. May range from colorless to amber or brown depending on formulation. Flammable toxic liquid at room temperature. |
| Flash Point | 23-61C (73-142F) typical for Class 3 flammable liquid |
| Boiling Point | Varies by formulation, typically 65-150C (149-302F) |
| Vapor Density | Greater than 1 (heavier than air) |
| Water Reactivity | No violent water reaction is expected, but water can spread toxic pesticide contamination; verify formulation-specific SDS. |
Fireground Response Guidance — UN 2778
Extinguishing Media
PPE Requirements
Level A or B required; full SCBA mandatory; chemical-resistant suit; mercury vapor highly toxic; avoid all skin contact
Isolation & Evacuation
First Actions for a UN 2778 Incident
- Call 911 and the emergency response number shown on the shipping papers.
- Keep unauthorized personnel away and establish an initial isolation perimeter.
- Stay upwind, uphill and upstream; avoid low areas where vapors or runoff may collect.
- Avoid breathing vapors, dust, mist or smoke and prevent skin and eye contact.
- Do not touch damaged packages, leaking containers or spilled material without appropriate PPE.
- Eliminate ignition sources; stop traffic, engines, smoking and open flames if it can be done safely.
- Ventilate confined spaces only when responders are trained, equipped and monitoring conditions.
- Use ERG, SDS, shipping papers and air monitoring to set final isolation, evacuation and decon actions.
📋 Copy & Share Field Card
UN 2778 — Mercury based pesticide, liquid, flammabUse 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.