☣️ UN 1595 • CLASS 6

Dimethyl sulphate

Placard: Toxic. 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.
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Quick details
UN 1595
Class: 6
Placard type: Toxic
ERG: Guide 156 (check current ERG)
Isolation: ERG 156: isolate spill 50m all directions; for large spill isolate 800m downwind; evacuate immediate area if fire involved
Chemical & Response Details
Also known asDMSMethyl sulfateSulfuric acid dimethyl esterDimethylsulfatDMSO4
CAS Number77-78-1
AppearanceColorless to pale yellow oily liquid with a faint onion-like odor. Denser than water and sinks.
Flash Point83°C (182°F)
Boiling Point188°C (370°F)
Vapor Density4.35 (heavier than air)
Water ReactivityReacts slowly with water forming sulfuric acid and methanol; reaction accelerates with heat producing corrosive and flammable decomposition products
ExtinguishingAlcohol-resistant foam, dry chemical, CO2; water spray for cooling only, not directly on material
PPE⚠️ Level A required for spill response; SCBA and full chemical-protective suit; extremely toxic by inhalation and skin absorption; delayed effects possible
IsolationERG 156: isolate spill 50m all directions; for large spill isolate 800m downwind; evacuate immediate area if fire involved
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • 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
First actions (field-minded)
  • 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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UN 1595 — Dimethyl sulphate
HAZMAT RADIO NOTE — UN 1595 Product: Dimethyl sulphate Class 6 / Toxic / ERG 156 PPE: Level A required for spill response; SCBA and full chemical-protective suit; extremely toxic by inhalation and skin absorption; delayed effects possible ISOLATION: ERG 156: isolate spill 50m all directions; for large spill isolate 800m downwind; evacuate immediate area if fire involved ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO

Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.

SMS WhatsApp
=== IC HAZMAT BRIEFING === UN 1595 — Dimethyl sulphate Class: 6 | Placard: Toxic | ERG Guide: 156 Appearance: Colorless to pale yellow oily liquid with a faint onion-like odor. Denser than water and sinks. Water Reactivity: Reacts slowly with water forming sulfuric acid and methanol; reaction accelerates with heat producing corrosive and flammable decomposition products Extinguishing: Alcohol-resistant foam, dry chemical, CO2; water spray for cooling only, not directly on material PPE: Level A required for spill response; SCBA and full chemical-protective suit; extremely toxic by inhalation and skin absorption; delayed effects possible Isolation: ERG 156: isolate spill 50m all directions; for large spill isolate 800m downwind; evacuate immediate area if fire involved — 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/1595 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.

SMS (short)
UN1595 Dimethyl sulphate Cls6 ERG156 | ERG 156: isolate spill 50m all directions; for large spill isolate 800m downwind | allfirefighter.com/hazmat/un/1595SMS / 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/1595
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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FAQ

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 A required for spill response; SCBA and full chemical-protective suit; extremely toxic by inhalation and skin absorption; delayed effects possible

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.