UN 3458 — Nitroanisoles, solid
Placard: Toxic. ERG Guide 152. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3458 is Nitroanisoles, solid, a toxic combustible nitroanisole solid assigned to ERG Guide 152. Isomer identity and dermal exposure must be verified.
Hazard overview: HIGHLY TOXIC methoxy nitroaromatic solid; inhalation, ingestion or skin absorption may cause severe injury. Combustible solid: may burn but does not ignite readily. Molten material can cause severe thermal/chemical burns and increase contact exposure.
Response guidance: For UN 3458, isolate the area, avoid skin contact and use SCBA where vapor, dust, mist or fire is present. Contain runoff and verify controls with SDS/ERG 152.
Firefighter training notes: Training for UN 3458 should emphasize exposure routes, SCBA use, vapor/dust monitoring, decontamination, runoff containment and SDS verification. Use ERG 152, SDS and local SOP.
Regulatory context: Nitroanisoles, solid is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, concentration, formulation and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Nitroanisoles, solid should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 3458 Quick Details
Common Hazards of UN 3458
- HIGHLY TOXIC methoxy nitroaromatic solid; inhalation, ingestion or skin absorption may cause severe injury.
- Combustible solid: may burn but does not ignite readily.
- Molten material can cause severe thermal/chemical burns and increase contact exposure.
- Dust, crystals or residue can contaminate clothing, tools and runoff.
- Fire may produce nitrogen oxides, hydrogen halides where applicable and toxic aromatic smoke.
- Runoff may carry persistent toxic nitroaromatic contamination.
- Exact isomer mixture and physical form should be verified from SDS.
Chemical Identity & Physical Properties
Yellowish to pale brown crystalline solid or powder with a faint aromatic odor. May be found as ortho-, meta-, or para- isomers.
| Also known as | Mononitro anisolesMethoxy nitrobenzenesNitro methoxybenzenesNitrated anisoles |
| Appearance | Yellowish to pale brown crystalline solid or powder with a faint aromatic odor. May be found as ortho-, meta-, or para- isomers. |
| Flash Point | 132-150C (270-302F) depending on isomer |
| Boiling Point | 258-272C (496-522F) depending on isomer |
| Vapor Density | 5.3 (heavier than air) |
| Water Reactivity | No significant reaction with water; very low solubility |
Fireground Response Guidance — UN 3458
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA where vapor, dust, mist, smoke or fire is present. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 3458 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.
- Do not touch damaged containers, equipment 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 152, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3458 — Nitroanisoles, solidUse 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.