UN 1990 — Benzaldehyde
Placard: Miscellaneous. ERG Guide 171. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1990 is Benzaldehyde, a Class 9 combustible organic liquid assigned to ERG Guide 171. It may burn when heated and can irritate eyes, skin and respiratory tract.
Hazard overview: COMBUSTIBLE Class 9 liquid; may burn but does not ignite readily. Vapors may irritate eyes, skin and respiratory tract. Heated containers may rupture or fail.
Response guidance: For a UN 1990 incident, verify the product with shipping papers, container markings, SDS and ERG Guide 171. Establish incident command, isolate the area, stay upwind, control ignition or downwind hazards, cool exposed containers from a protected distance when appropriate and base entry decisions on monitoring and local SOP.
Firefighter training notes: Training for UN 1990 should emphasize fire behavior, exposure routes, air monitoring, PPE selection, evacuation, runoff control and ERG/SDS verification. Use ERG 171, SDS and local SOP.
Regulatory context: Benzaldehyde is regulated as a hazardous material for transportation and emergency response purposes. Storage, workplace exposure, emergency planning, spill reporting and waste handling requirements vary by exact product, concentration, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, container markings and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Benzaldehyde should be stored in compatible containers in a secure, cool, ventilated hazardous-material area according to SDS and local procedures.
UN 1990 Quick Details
Common Hazards of UN 1990
- COMBUSTIBLE Class 9 liquid; may burn but does not ignite readily.
- Vapors may irritate eyes, skin and respiratory tract.
- Heated containers may rupture or fail.
- Fire may produce irritating and/or toxic smoke including carbon monoxide.
- Liquid is only slightly soluble and may spread on surfaces or water.
- Runoff may carry organic liquid contamination.
- Specific exposure limits and cleanup methods should be verified from SDS.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid with a characteristic bitter almond odor. Oily consistency at room temperature.
| Also known as | Benzoic aldehydeBenzenecarboxaldehydePhenylmethanalArtificial almond oil |
| CAS Number | 100-52-7 |
| Appearance | Colorless to pale yellow liquid with a characteristic bitter almond odor. Oily consistency at room temperature. |
| Flash Point | 63C (145F) |
| Boiling Point | 179C (354F) |
| Vapor Density | 3.7 (heavier than air) |
| Water Reactivity | Insoluble in water; no significant reaction |
Fireground Response Guidance — UN 1990
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for fire, heavy vapor or confined-space exposure. Wear chemical-resistant gloves, eye/face protection and protective clothing selected from SDS.
Isolation & Evacuation
First Actions for a UN 1990 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, gas, smoke, mist or dust and avoid skin or eye contact.
- Do not touch damaged containers or spilled/released 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 release or spill area and expand the perimeter for fire involvement, vapor accumulation, cylinder/tank heating or unknown product identity.
- Use ERG Guide 171, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1990 — BenzaldehydeUse 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.