UN 3071 — Mercaptan mixture, liquid, poisonous, flammable, n.o.s.
Placard: Toxic. ERG Guide 131. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3071 is Mercaptan mixture, liquid, poisonous, flammable, n.o.s., a toxic flammable n.o.s. mercaptan mixture assigned to ERG Guide 131. Odor is not a safe exposure indicator.
Hazard overview: TOXIC and FLAMMABLE mercaptan mixture; inhalation, ingestion or skin absorption may cause severe injury. Vapors may ignite and form explosive mixtures with air. Very strong odor does not reliably indicate safe concentration or exposure limits.
Response guidance: For UN 3071, isolate the area, avoid skin contact and use SCBA where vapor, dust, mist or fire is present. Contain runoff and verify controls with SDS and ERG 131.
Firefighter training notes: Training for UN 3071 should emphasize exposure routes, SCBA use, vapor/dust monitoring, decontamination, runoff containment and SDS/package verification. Use ERG 131, SDS and local SOP.
Regulatory context: Mercaptan mixture, liquid, poisonous, flammable, n.o.s. is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, formulation and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Mercaptan mixture, liquid, poisonous, flammable, n.o.s. should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 3071 Quick Details
Common Hazards of UN 3071
- TOXIC and FLAMMABLE mercaptan mixture; inhalation, ingestion or skin absorption may cause severe injury.
- Vapors may ignite and form explosive mixtures with air.
- Very strong odor does not reliably indicate safe concentration or exposure limits.
- Vapors are heavier than air and may collect in low or confined areas.
- Fire may produce sulfur oxides and irritating/toxic smoke.
- Runoff may carry toxic sulfur-containing contamination.
- Exact mercaptan composition must be verified from SDS and shipping papers.
Chemical Identity & Physical Properties
Clear to pale yellow liquid with an extremely strong, offensive, putrid odor resembling rotten cabbage or garlic. Liquid at room temperature.
| Also known as | Mercaptan blendThiol mixtureOrganic sulfur compound mixtureFlammable poisonous mercaptan solution |
| Appearance | Clear to pale yellow liquid with an extremely strong, offensive, putrid odor resembling rotten cabbage or garlic. Liquid at room temperature. |
| Flash Point | Varies by composition, typically below 23C (73F) for flammable mercaptans |
| Boiling Point | Varies by composition, typically 35-150C (95-302F) depending on specific mercaptan components |
| Vapor Density | 2-4 (heavier than air), vapors will accumulate in low-lying areas |
| Water Reactivity | No significant reaction with water, but insoluble or slightly soluble; releases toxic vapors |
Fireground Response Guidance — UN 3071
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, dust, mist, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 3071 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.
- Eliminate ignition sources if this can be done safely.
- Avoid breathing vapor, dust, gas, mist, smoke or fumes and avoid skin or eye contact.
- Do not touch damaged containers 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 131, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3071 — Mercaptan mixture, liquid, poisonous, flUse 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.