☣️ UN 1831 • CLASS 8

Sulphuric acid, fuming

Placard: Corrosive. 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.
Advertisement
Quick details
UN 1831
Class: 8
Placard type: Corrosive
ERG: Guide 137 (check current ERG)
Isolation: ERG 137: Initial isolation 60m (200 ft) all directions. Protective action distance up to 0.8 km (0.5 mi) downwind for large spill. Evacuate immediate area if container exposed to fire.
Chemical & Response Details
Also known asOleumFuming sulfuric acidDisulfuric acidPyrosulfuric acidNordhauser acid
CAS Number8014-95-7
AppearanceDense, colorless to dark brown oily liquid that fumes heavily in moist air, producing thick white vapors with a pungent, choking odor. Contains dissolved sulfur trioxide (SO3) in concentrated sulfuric acid.
Flash PointNot applicable (non-flammable)
Boiling PointApproximately 338C (640F), varies with SO3 concentration
Vapor Density3.4 (heavier than air)
Water ReactivityReacts violently with water, generating extreme heat and spattering. Never add water to acid. May boil and release dense toxic SO3 fumes.
ExtinguishingDo not use water or foam. Use dry chemical, soda ash, or lime to neutralize spills. CO2 ineffective.
PPE⚠️ Level A required for significant spills or leaks. Full encapsulating suit, SCBA, acid-resistant gloves and boots. Extreme corrosive hazard to skin, eyes, respiratory tract.
IsolationERG 137: Initial isolation 60m (200 ft) all directions. Protective action distance up to 0.8 km (0.5 mi) downwind for large spill. Evacuate immediate area if container exposed to fire.
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • CORROSIVE and/or TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance
  • Fire will produce irritating, corrosive and/or toxic gases.
  • Reaction with water may generate much heat that will increase the concentration of fumes in the air.
  • Contact with molten substance may cause severe burns to skin and eyes.
  • Runoff from fire control or dilution water may cause environmental contamination.
  • EXCEPT FOR ACETIC ANHYDRIDE (UN1715), THAT IS FLAMMABLE, some of these materials may
  • May ignite combustibles (wood, paper, oil, clothing, etc.).
  • Substance will react with water (some violently), releasing corrosive and/or toxic gases and runoff.
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
Advertisement
📋 Copy & Share
UN 1831 — Sulphuric acid, fuming
HAZMAT RADIO NOTE — UN 1831 Product: Sulphuric acid, fuming Class 8 / Corrosive / ERG 137 PPE: Level A required for significant spills or leaks. Full encapsulating suit, SCBA, acid-resistant gloves and boots. Extreme corrosive hazard to skin, eyes, respiratory tract. ISOLATION: ERG 137: Initial isolation 60m (200 ft) all directions. Protective action distance up to 0.8 km (0.5 mi) downwind for large spill. Evacuate immediate area if container exposed to fire. 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 1831 — Sulphuric acid, fuming Class: 8 | Placard: Corrosive | ERG Guide: 137 Appearance: Dense, colorless to dark brown oily liquid that fumes heavily in moist air, producing thick white vapors with a pungent, choking odor. Contains dissolved sulfur trioxide (SO3) in concentrated sulfuric acid. Water Reactivity: Reacts violently with water, generating extreme heat and spattering. Never add water to acid. May boil and release dense toxic SO3 fumes. Extinguishing: Do not use water or foam. Use dry chemical, soda ash, or lime to neutralize spills. CO2 ineffective. PPE: Level A required for significant spills or leaks. Full encapsulating suit, SCBA, acid-resistant gloves and boots. Extreme corrosive hazard to skin, eyes, respiratory tract. Isolation: ERG 137: Initial isolation 60m (200 ft) all directions. Protective action distance up to 0.8 km (0.5 mi) downwind for large spill. Evacuate immediate area if container exposed to fire. — Key Hazards — • CORROSIVE and/or TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance • Fire will produce irritating, corrosive and/or toxic gases. • Reaction with water may generate much heat that will increase the concentration of fumes in the air. — 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/1831 | 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)
UN1831 Sulphuric acid, fuming Cls8 ERG137 | ERG 137: Initial isolation 60m (200 ft) all directions. Protective action distan | allfirefighter.com/hazmat/un/1831SMS / 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/1831
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
Advertisement

FAQ

CORROSIVE and/or TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance Fire will produce irritating, corrosive and/or toxic gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Contact with molten substance may cause severe burns to skin and eyes. Runoff from fire control or dilution water may cause environmental contamination. EXCEPT FOR ACETIC ANHYDRIDE (UN1715), THAT IS FLAMMABLE, some of these materials may May ignite combustibles (wood, paper, oil, clothing, etc.). Substance will react with water (some violently), releasing corrosive and/or toxic gases and runoff.

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 significant spills or leaks. Full encapsulating suit, SCBA, acid-resistant gloves and boots. Extreme corrosive hazard to skin, eyes, respiratory tract.

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 137 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.