UN 1803 — Phenolsulphonic acid, liquid
Placard: Corrosive. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1803 is Phenolsulphonic acid, liquid, a corrosive phenolic sulfonic acid liquid assigned to ERG Guide 153. It can cling to surfaces and clothing, causing acidic burns and contaminated runoff.
Hazard overview: UN 1803 presents corrosive liquid, heat-on-dilution, phenolic organic acid and acidic-runoff hazards. Fire may produce sulfur oxides and irritating or toxic smoke.
Response guidance: For a UN 1803 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 153. Establish incident command, isolate the area, stay upwind, prevent incompatible contact, control runoff and choose entry or fire-control actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1803 should emphasize corrosive exposure routes, water or oxidizer incompatibility where applicable, air monitoring, PPE selection, decontamination and runoff containment. Use ERG 153, SDS and local SOP.
Regulatory context: Phenolsulphonic acid, liquid 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 concentration, 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: Phenolsulphonic acid, liquid should be stored in tightly closed compatible containers in a secure, cool, dry, well-ventilated hazardous-material area according to SDS and local procedures.
UN 1803 Quick Details
Common Hazards of UN 1803
- CORROSIVE phenolic sulfonic acid liquid; inhalation, ingestion or skin/eye contact may cause severe injury.
- Liquid may be viscous and can cling to skin, clothing, tools and surfaces.
- Dilution with water may generate heat and spread acidic contamination.
- Combustibility is low for many solutions, but organic acid residues may burn under fire conditions.
- Fire may produce sulfur oxides, phenolic smoke and other irritating/toxic gases.
- Runoff may be acidic, corrosive and environmentally harmful.
- Containers may rupture or fail when heated.
Chemical Identity & Physical Properties
Colorless to pale yellow viscous liquid or syrupy solution. Acidic odor. Corrosive and hygroscopic.
| Also known as | p-Phenolsulfonic acid4-Hydroxybenzenesulfonic acidSulphocarbolic acidp-Sulfophenol |
| CAS Number | 98-67-9 |
| Appearance | Colorless to pale yellow viscous liquid or syrupy solution. Acidic odor. Corrosive and hygroscopic. |
| Flash Point | Not applicable (non-flammable aqueous solution) |
| Boiling Point | Decomposes before boiling at approximately 100C (212F) |
| Vapor Density | Not applicable (low volatility liquid) |
| Water Reactivity | Soluble in water, releases heat upon dilution. Handle with care when mixing with water. |
Fireground Response Guidance — UN 1803
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, mist, dust, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing selected from SDS for corrosive contact.
Isolation & Evacuation
First Actions for a UN 1803 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, mist or spray and avoid skin or eye contact.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- 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 vapor, dust, fire involvement, water reaction or unknown concentration is present.
- Use ERG Guide 153, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1803 — Phenolsulphonic acid, liquidUse 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.