UN 2845 — Ethyl phosphonous dichloride, anhydrous
Placard: Toxic. ERG Guide 135. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2845 At a Glance
UN 2845 (Ethyl phosphonous dichloride, anhydrous) is listed as DOT Class 6 Toxic and is assigned to ERG Guide 135. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
UN 2845 is Ethyl phosphonous dichloride, anhydrous, a toxic corrosive anhydrous phosphorus chloride assigned to ERG Guide 135. Moisture releases HCl and heat.
Hazard overview: TOXIC, CORROSIVE and water-reactive organophosphorus chloride; inhalation or contact can cause severe injury. Reacts with water or moist air, releasing hydrogen chloride, heat and acidic phosphorus-containing products. May be flammable or combustible depending on conditions; keep ignition sources away.
Response guidance: For UN 2845, isolate the spill, stay upwind and use SCBA with chemical protection. Control moisture contact, use compatible dry agents and contain acidic/toxic runoff under ERG 135.
Firefighter training notes: Training for UN 2845 should emphasize moisture-reactive corrosive fuming, dry-agent choice, SCBA/Level A decisions, decontamination and acidic runoff control. Use ERG 135, SDS and local SOP.
Regulatory context: Ethyl phosphonous dichloride, anhydrous is regulated as a hazardous material for transport and emergency response. Storage, exposure, spill reporting, waste and fire-code duties depend on quantity, concentration and jurisdiction; verify shipping papers, SDS and local authority requirements.
Storage & handling: Ethyl phosphonous dichloride, anhydrous should be stored dry in tightly closed compatible containers away from water, moisture, bases, alcohols/amines where incompatible, heat and unauthorized access.
UN 2845 Quick Details
Common Hazards of UN 2845
- TOXIC, CORROSIVE and water-reactive organophosphorus chloride; inhalation or contact can cause severe injury.
- Reacts with water or moist air, releasing hydrogen chloride, heat and acidic phosphorus-containing products.
- May be flammable or combustible depending on conditions; keep ignition sources away.
- Fumes are corrosive and can collect in poorly ventilated or low areas.
- Fire may produce hydrogen chloride, phosphorus oxides and other toxic/corrosive gases.
- Runoff may be acidic, toxic and corrosive.
- Containers may rupture when heated or contaminated with water.
Chemical Identity & Physical Properties
Colorless to pale yellow fuming liquid with a pungent, irritating odor. Fumes in moist air due to hydrolysis reaction.
| Also known as | Ethylphosphonous dichlorideEthyl dichlorophosphineDichloroethylphosphineEthylphosphorous dichloride |
| CAS Number | 1498-51-7 |
| Appearance | Colorless to pale yellow fuming liquid with a pungent, irritating odor. Fumes in moist air due to hydrolysis reaction. |
| Flash Point | Not applicable (pyrophoric/water-reactive) |
| Boiling Point | 58-60C (136-140F) |
| Vapor Density | 4.1 (heavier than air) |
| Water Reactivity | Reacts violently with water producing toxic and flammable phosphine gas and hydrochloric acid. Do not use water except as fog for cooling. |
Fireground Response Guidance — UN 2845
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and chemical-resistant protective clothing. Level A may be needed for heavy vapor, splash, fuming or unknown concentrations.
Isolation & Evacuation
First Actions for a UN 2845 Incident
- Call 911 and the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command.
- Stay upwind, uphill and upstream.
- Avoid breathing vapor, dust, mist, smoke or fumes and avoid skin or eye contact.
- Keep water or moisture contact controlled because reaction or re-ignition hazards may be severe.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Prevent contaminated liquid, dust, runoff and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 135, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2845 — Ethyl phosphonous dichloride, anhydrousUse 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.