UN 1656 — Nicotine hydrochloride, solution
Placard: Toxic. ERG Guide 151. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1656 is Nicotine hydrochloride, solution, a highly toxic nicotine material assigned to ERG Guide 151. Skin absorption is a major responder concern, especially with liquids, solutions, salts or contaminated solids.
Hazard overview: UN 1656 presents toxic dermal absorption, ingestion, inhalation and contaminated-runoff hazards. Flammability depends on the formulation, but fire can produce toxic smoke and contaminated water.
Response guidance: For a UN 1656 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 151. Establish incident command, isolate the area, stay upwind, prevent dust or vapor exposure, control runoff and choose entry or cleanup actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1656 should emphasize rapid dermal absorption, vapor/mist control, decontamination, contaminated clothing control and formulation-dependent flammability. Use ERG 151, SDS and local SOP.
Regulatory context: Nicotine hydrochloride, solution 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, concentration, 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: Nicotine hydrochloride, solution should be stored in tightly closed compatible containers in a secure, cool, well-ventilated toxic-material area away from heat, oxidizers, incompatible chemicals, food/feed and unauthorized access. Prevent leaks, contaminated packaging and skin-contact exposure.
UN 1656 Quick Details
Common Hazards of UN 1656
- HIGHLY TOXIC nicotine material; inhalation, ingestion or skin absorption may be fatal.
- Skin contact can be a major exposure route, especially with liquid, solution or contaminated solids.
- Vapors or mist may be heavier than air and collect in low or confined areas when heated or released.
- Combustibility depends on formulation; pure nicotine is combustible and many preparations may burn under fire conditions.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff may spread toxic nicotine contamination.
- Containers may rupture or fail when heated.
Chemical Identity & Physical Properties
Clear to pale yellow or amber liquid solution with characteristic tobacco-like odor. The pure salt is a white crystalline solid, but typically shipped as an aqueous solution.
| Also known as | Nicotine hydrochlorideNicotine HCl3-(1-Methylpyrrolidin-2-yl)pyridine hydrochlorideNicotinium chloride |
| CAS Number | 2820-51-1 |
| Appearance | Clear to pale yellow or amber liquid solution with characteristic tobacco-like odor. The pure salt is a white crystalline solid, but typically shipped as an aqueous solution. |
| Flash Point | Depends on solution concentration and solvent; aqueous solutions may be non-flammable, but organic solvent solutions may have flash points below 23C (73F) |
| Boiling Point | Aqueous solutions boil near 100C (212F); pure nicotine base boils at 247C (477F) |
| Vapor Density | Approximately 5.6 for nicotine vapor (heavier than air); solution vapor density depends on concentration |
| Water Reactivity | No significant reaction; nicotine hydrochloride is water-soluble and commonly prepared as aqueous solution |
Fireground Response Guidance — UN 1656
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and chemical protective clothing selected by hazmat specialists. Level A or B may be needed depending on release size and concentration; prevent skin contact because nicotine can be absorbed rapidly through skin.
Isolation & Evacuation
First Actions for a UN 1656 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 breathing vapors, fumes, dust or mist and avoid all skin or eye contact.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Avoid creating dust clouds or spreading contaminated liquid, powder, solution, runoff or debris.
- 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 dust, vapor, fire involvement or unknown concentration is present.
- Use ERG Guide 151, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1656 — Nicotine hydrochloride, solutionUse 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.