☣️ UN 1244 • CLASS 6
UN 1244 — Methylhydrazine
Placard: Toxic. ERG Guide 131. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
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⚠️ 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.
Methylhydrazine is a highly toxic and corrosive liquid that can cause severe health effects. It is a colorless to pale yellow fuming liquid with an ammonia-like or fishy odor.
Hazard overview: Methylhydrazine is toxic and may be fatal if inhaled, ingested, or absorbed through skin. It can also cause skin and eye irritation.
Response guidance: In case of emergency, evacuate the area and provide medical attention immediately. Use alcohol-resistant foam, CO2, or dry chemical to extinguish fires.
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UN 1244 Quick Details
UN 1244
Product name: Methylhydrazine
DOT Class: 6
Placard type: Toxic
ERG Guide: 131 (check current ERG)
Initial isolation: ERG 131: Small spill isolate 60m, large spill 150m; downwind evacuate 800m day, 1600m night if tank/rail car involved
Common Hazards of UN 1244
- TOXIC; may be fatal if inhaled, ingested or absorbed through skin.
- Inhalation or contact with some of these materials will irritate or burn skin and eyes.
- Methyl chloroacetate (UN2295) is an eye irritant/lachrymator (causes flow of tears).
- Fire will produce irritating, corrosive and/or toxic gases.
- Vapors may cause dizziness or asphyxiation, especially when in closed or confined areas.
- Runoff from fire control or dilution water may cause environmental contamination.
- HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
- Vapors may form explosive mixtures with air.
Chemical Identity & Physical Properties
Methylhydrazine is a colorless to pale yellow fuming liquid with an ammonia-like or fishy odor.
| Also known as | MMHMonomethylhydrazine1-MethylhydrazineHydrazomethaneN-Methylhydrazine |
| CAS Number | 60-34-4 |
| Appearance | Colorless to pale yellow fuming liquid with an ammonia-like or fishy odor. Hygroscopic and fuming in air. |
| Flash Point | -8C (17F) |
| Boiling Point | 87C (189F) |
| Vapor Density | 1.6 (heavier than air) |
| Water Reactivity | Soluble in water; no violent reaction but solution is corrosive and toxic |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1244
Extinguishing Media
Alcohol-resistant foam, CO2, dry chemical; regular foam may be ineffective
PPE Requirements
⚠️ Level A required; SCBA mandatory; chemically resistant suit; extremely toxic by all routes
Wear Level A PPE, including a chemically resistant suit, SCBA, and splash goggles.
Isolation & Evacuation
ERG 131: Small spill isolate 60m, large spill 150m; downwind evacuate 800m day, 1600m night if tank/rail car involved
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 131).
First Actions for a UN 1244 Incident
- 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.
- 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 1244 — MethylhydrazineHAZMAT RADIO NOTE — UN 1244
Product: Methylhydrazine
Class 6 / Toxic / ERG 131
PPE: Level A required; SCBA mandatory; chemically resistant suit; extremely toxic by all routes
ISOLATION: ERG 131: Small spill isolate 60m, large spill 150m; downwind evacuate 800m day, 1600m night if tank/rail car involved
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 1244 — Methylhydrazine
Class: 6 | Placard: Toxic | ERG Guide: 131
Appearance: Colorless to pale yellow fuming liquid with an ammonia-like or fishy odor. Hygroscopic and fuming in air.
Water Reactivity: Soluble in water; no violent reaction but solution is corrosive and toxic
Extinguishing: Alcohol-resistant foam, CO2, dry chemical; regular foam may be ineffective
PPE: Level A required; SCBA mandatory; chemically resistant suit; extremely toxic by all routes
Isolation: ERG 131: Small spill isolate 60m, large spill 150m; downwind evacuate 800m day, 1600m night if tank/rail car involved
— Key Hazards —
• TOXIC; may be fatal if inhaled, ingested or absorbed through skin.
• Inhalation or contact with some of these materials will irritate or burn skin and eyes.
• Methyl chloroacetate (UN2295) is an eye irritant/lachrymator (causes flow of tears).
— First Actions —
• 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.
SOURCE: allfirefighter.com/hazmat/un/1244 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN1244 Methylhydrazine Cls6 ERG131 | ERG 131: Small spill isolate 60m, large spill 150m; downwind evacuate 800m day, | allfirefighter.com/hazmat/un/1244SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions.
Page: https://allfirefighter.com/hazmat/un/methylhydrazine-un-1244
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Frequently Asked Questions about UN 1244
Yes, methylhydrazine is highly flammable.
Yes, methylhydrazine is toxic and may be fatal if inhaled, ingested, or absorbed through skin.
Yes, methylhydrazine can cause skin and eye irritation.
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.