☣️ UN 1111 • CLASS 3
UN 1111 — Amyl mercaptan
Placard: Flammable. ERG Guide 130. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
🚒☣️
⚠️ This page is a quick-reference aid. For real incidents: stage upwind, isolate, deny entry, request Hazmat early, and consult the current ERG + SOP/SOG.
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UN 1111 Quick Details
UN 1111
Product name: Amyl mercaptan
DOT Class: 3
Placard type: Flammable
ERG Guide: 130 (check current ERG)
Initial isolation: ERG 130: Initial isolation 50m all directions; if tank/rail car involved in fire, isolate 800m all directions
Common Hazards of UN 1111
- HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
- Vapors may form explosive mixtures with air.
- Vapors may travel to source of ignition and flash back.
- Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas
- Vapor explosion hazard indoors, outdoors or in sewers.
- Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
- Runoff to sewer may create fire or explosion hazard.
- Containers may explode when heated.
Chemical Identity & Physical Properties
| Also known as | 1-PentanethiolPentyl mercaptann-Amyl mercaptanPentan-1-thiol |
| CAS Number | 110-66-7 |
| Appearance | Colorless to pale yellow liquid with a strong, offensive, skunk-like odor. Liquid at room temperature with characteristic mercaptan smell. |
| Flash Point | -18°C (0°F) |
| Boiling Point | 126°C (259°F) |
| Vapor Density | 3.6 (heavier than air) |
| Water Reactivity | No significant reaction; immiscible with water, floats on surface |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1111
Extinguishing Media
Alcohol-resistant foam, dry chemical, CO2; water spray for cooling only
PPE Requirements
⚠️ Level B minimum recommended; SCBA required due to toxic vapors and offensive odor; chemical-resistant suit and gloves
Isolation & Evacuation
ERG 130: Initial isolation 50m all directions; if tank/rail car involved in fire, isolate 800m all directions
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 130).
First Actions for a UN 1111 Incident
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area for at least 50 meters (150 feet) in all directions.
- Consider initial downwind evacuation for at least 300 meters (1000 feet).
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📋 Copy & Share Field Card
UN 1111 — Amyl mercaptanHAZMAT RADIO NOTE — UN 1111
Product: Amyl mercaptan
Class 3 / Flammable / ERG 130
PPE: Level B minimum recommended; SCBA required due to toxic vapors and offensive odor; chemical-resistant suit and gloves
ISOLATION: ERG 130: Initial isolation 50m all directions; if tank/rail car involved in fire, isolate 800m all directions
ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO
Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
=== IC HAZMAT BRIEFING ===
UN 1111 — Amyl mercaptan
Class: 3 | Placard: Flammable | ERG Guide: 130
Appearance: Colorless to pale yellow liquid with a strong, offensive, skunk-like odor. Liquid at room temperature with characteristic mercaptan smell.
Water Reactivity: No significant reaction; immiscible with water, floats on surface
Extinguishing: Alcohol-resistant foam, dry chemical, CO2; water spray for cooling only
PPE: Level B minimum recommended; SCBA required due to toxic vapors and offensive odor; chemical-resistant suit and gloves
Isolation: ERG 130: Initial isolation 50m all directions; if tank/rail car involved in fire, isolate 800m all directions
— Key Hazards —
• HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
• Vapors may form explosive mixtures with air.
• Vapors may travel to source of ignition and flash back.
— First Actions —
• CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
• Keep unauthorized personnel away.
• Stay upwind, uphill and/or upstream.
• Ventilate closed spaces before entering, but only if properly trained and equipped.
SOURCE: allfirefighter.com/hazmat/un/1111 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1111 Amyl mercaptan Cls3 ERG130 | ERG 130: Initial isolation 50m all directions; if tank/rail car involved in fire | allfirefighter.com/hazmat/un/1111SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS. Includes link to full page.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions.
Page: https://allfirefighter.com/hazmat/un/1111
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Frequently Asked Questions about UN 1111
HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas Vapor explosion hazard indoors, outdoors or in sewers. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated.
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Keep unauthorized personnel away. Stay upwind, uphill and/or upstream.
Level B minimum recommended; SCBA required due to toxic vapors and offensive odor; chemical-resistant suit and gloves
Water reactivity: No significant reaction; immiscible with water, floats on surface. Recommended extinguishing: Alcohol-resistant foam, dry chemical, CO2; water spray for cooling only.
ERG Guide 130 recommendation: ERG 130: Initial isolation 50m all directions; if tank/rail car involved in fire, isolate 800m all directions
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 130 and your department SOP/SOG for incident-specific protective actions.
Sources (high level): DOT/PHMSA marking & class concepts + ERG usage principles.
This page does not reproduce ERG guide text—always consult the current ERG for incident-specific protective actions.