UN 2577 — Phenylacetyl chloride
Placard: Corrosive. ERG Guide 156. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Phenylacetyl chloride is a corrosive organic acid chloride. It is combustible and reacts with moisture, so response planning must account for acid gas, flashback potential and water sensitivity.
Hazard overview: Moisture or water can generate hydrogen chloride fumes and heat. Vapors may be heavier than air, and heated material can form ignitable mixtures in confined or low spaces.
Response guidance: Eliminate ignition sources, isolate drains and keep personnel uphill and upwind. Use dry chemical, CO2 or dry sand for small product fires or spills when appropriate, and avoid directing water into the liquid; cool exposed containers from a protected position.
Firefighter training notes: Train crews on acid chloride moisture reactions, vapor travel and protected container cooling. Emphasize avoiding water application to product while still cooling threatened containers.
Regulatory context: UN 2577 is shipped as Phenylacetyl chloride, Class 8 corrosive. Shipping papers and SDS should confirm purity, inhibitors if any, and emergency contact information.
Storage & handling: Store in dry, tightly closed containers away from water, bases, alcohols, oxidizers, metals and ignition sources.
UN 2577 Quick Details
Common Hazards of UN 2577
- Combustible corrosive liquid; heating can produce ignitable vapors and toxic acid gases.
- Reacts with water or moisture to release hydrogen chloride fumes and heat.
- Vapors are heavier than air and may move along the ground to ignition sources.
- Corrosive vapors and liquid can burn skin, eyes and respiratory tissue.
- Contact with some metals may generate flammable hydrogen gas.
- Containers may rupture if heated or contaminated with water.
- Spill runoff can be acidic and harmful to drains or waterways.
Chemical Identity & Physical Properties
Phenylacetyl chloride is a colorless to pale yellow liquid with a pungent acrid odor. It may fume in moist air and can form acidic vapors.
| Also known as | Phenylacetyl chlorideBenzeneacetyl chloridePhenylethanoyl chlorideα-Toluoyl chloridePhenylacetic acid chloride |
| CAS Number | 103-80-0 |
| Appearance | Colorless to pale yellow liquid with a pungent, acrid odor. Corrosive organic acid chloride that fumes in moist air. |
| Flash Point | 110°C (230°F) |
| Boiling Point | 210-215°C (410-419°F) |
| Vapor Density | 5.3 (heavier than air) |
| Water Reactivity | Reacts violently with water releasing toxic and corrosive hydrogen chloride gas (HCl) and heat. Do not use water directly on material. |
Fireground Response Guidance — UN 2577
Extinguishing Media
PPE Requirements
Use SCBA and acid-resistant chemical protective clothing. Gloves, boots and face protection must be compatible with acid chlorides and organic solvents.
Isolation & Evacuation
First Actions for a UN 2577 Incident
- Call 911 and the emergency response number shown on shipping papers; confirm the material with ERG, SDS and container markings.
- Keep unauthorized personnel away and establish hot, warm and cold zones before entry.
- Stay upwind, uphill and upstream; avoid low areas where vapors, dust or runoff may collect.
- Avoid breathing vapors, dust, mist or decomposition products and prevent skin or eye contact.
- Do not touch damaged packages or containers unless properly trained and wearing suitable chemical PPE.
- Ventilate confined spaces only after atmospheric monitoring and only with trained, equipped personnel.
- Use ERG Guide 156, SDS, shipping papers and monitoring results for isolation, PPE and fire-control decisions.
📋 Copy & Share Field Card
UN 2577 — Phenylacetyl chlorideUse 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.