☣️ UN 2236 • CLASS 6
UN 2236 — 3-Chloro-4-methylphenyl isocyanate, liquid
Placard: Toxic. ERG Guide 156. 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 2236 Quick Details
UN 2236
Product name: 3-Chloro-4-methylphenyl isocyanate, liquid
DOT Class: 6
Placard type: Toxic
ERG Guide: 156 (check current ERG)
Initial isolation: ERG 156: Isolate spill or leak area immediately for at least 25-50 meters in all directions. If tank/rail car involved in fire, isolate 800 meters in all directions and consider initial evacuation for 800 meters.
Common Hazards of UN 2236
- Combustible material: may burn but does not ignite readily.
- Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff.
- When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion
- Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas
- Vapors may travel to source of ignition and flash back.
- Corrosives in contact with metals may evolve flammable hydrogen gas.
- Containers may explode when heated or if contaminated with water.
- TOXIC and/or CORROSIVE; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance
Chemical Identity & Physical Properties
| Also known as | 3-Chloro-4-methylphenyl isocyanateIsocyanic acid, 3-chloro-4-methylphenyl ester3-Chloro-p-cresyl isocyanate6-Chloro-4-cresyl isocyanate |
| CAS Number | 28479-22-3 |
| Appearance | Colorless to pale yellow liquid with a sharp, pungent, irritating odor. Isocyanate functional group makes it highly reactive. |
| Flash Point | 118°C (244°F) |
| Boiling Point | Approximately 240-250°C (464-482°F) |
| Vapor Density | 5.8 (heavier than air) |
| Water Reactivity | Reacts with water releasing toxic and corrosive gases (carbon dioxide, hydrogen chloride, amines). Reaction is exothermic and may be violent. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 2236
Extinguishing Media
Dry chemical, CO2, or foam if alcohol-resistant. Avoid water spray directly on liquid.
PPE Requirements
⚠️ Level B minimum with full-face SCBA required. Chemical-resistant suit, gloves, and boots. Avoid all skin and eye contact due to severe irritant properties.
Isolation & Evacuation
ERG 156: Isolate spill or leak area immediately for at least 25-50 meters in all directions. If tank/rail car involved in fire, isolate 800 meters in all directions and consider initial evacuation for 800 meters.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 156).
First Actions for a UN 2236 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 in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
- For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
- For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind
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📋 Copy & Share Field Card
UN 2236 — 3-Chloro-4-methylphenyl isocyanate, liquHAZMAT RADIO NOTE — UN 2236
Product: 3-Chloro-4-methylphenyl isocyanate, liquid
Class 6 / Toxic / ERG 156
PPE: Level B minimum with full-face SCBA required. Chemical-resistant suit, gloves, and boots. Avoid all skin and eye contact due to severe irritant properties.
ISOLATION: ERG 156: Isolate spill or leak area immediately for at least 25-50 meters in all directions. If tank/rail car involved in fire, isolate 800 meters in all directions and consider initial evacuation for 800 meters.
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 2236 — 3-Chloro-4-methylphenyl isocyanate, liquid
Class: 6 | Placard: Toxic | ERG Guide: 156
Appearance: Colorless to pale yellow liquid with a sharp, pungent, irritating odor. Isocyanate functional group makes it highly reactive.
Water Reactivity: Reacts with water releasing toxic and corrosive gases (carbon dioxide, hydrogen chloride, amines). Reaction is exothermic and may be violent.
Extinguishing: Dry chemical, CO2, or foam if alcohol-resistant. Avoid water spray directly on liquid.
PPE: Level B minimum with full-face SCBA required. Chemical-resistant suit, gloves, and boots. Avoid all skin and eye contact due to severe irritant properties.
Isolation: ERG 156: Isolate spill or leak area immediately for at least 25-50 meters in all directions. If tank/rail car involved in fire, isolate 800 meters in all directions and consider initial evacuation for 800 meters.
— Key Hazards —
• Combustible material: may burn but does not ignite readily.
• Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff.
• When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion
— 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/2236 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2236 3-Chloro-4-methylphenyl isocyanate, liquid Cls6 ERG156 | allfirefighter.com/hazmat/un/2236SMS / 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/2236
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Frequently Asked Questions about UN 2236
Combustible material: may burn but does not ignite readily. Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas Vapors may travel to source of ignition and flash back. Corrosives in contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water. TOXIC and/or CORROSIVE; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance
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 with full-face SCBA required. Chemical-resistant suit, gloves, and boots. Avoid all skin and eye contact due to severe irritant properties.
Water reactivity: Reacts with water releasing toxic and corrosive gases (carbon dioxide, hydrogen chloride, amines). Reaction is exothermic and may be violent.. Recommended extinguishing: Dry chemical, CO2, or foam if alcohol-resistant. Avoid water spray directly on liquid..
ERG Guide 156 recommendation: ERG 156: Isolate spill or leak area immediately for at least 25-50 meters in all directions. If tank/rail car involved in fire, isolate 800 meters in all directions and consider initial evacuation for 800 meters.
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 156 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.