☣️ UN 2693 • CLASS 8
Bisulphites, aqueous solution, n.o.s.
Placard: Corrosive. 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 2693
Class: 8
Placard type: Corrosive
ERG: Guide 154 (check current ERG)
Isolation: ERG 154: isolate spill 25-50m; if tank/rail car involved in fire, isolate 800m all directions
Chemical & Response Details
| Also known as | Bisulfites aqueous solutionHydrogen sulfite solutionAcid sulfite solutionBisulphite liquorHSO3- solution |
| Appearance | Clear to yellowish aqueous solution with a pungent, sharp sulfur dioxide odor. Liquid at room temperature with acidic pH. |
| Flash Point | Not applicable (non-flammable aqueous solution) |
| Boiling Point | Approximately 100C (212F), similar to water depending on concentration |
| Vapor Density | Not applicable (aqueous solution; vapors if any are SO2) |
| Water Reactivity | Miscible with water; may release sulfur dioxide gas upon dilution or heating |
| Extinguishing | Water spray, fog, or regular foam acceptable for neighboring fires |
| PPE | ⚠️ Level B minimum; chemical-resistant suit, gloves, boots; SCBA for vapor exposure; face shield and eye protection mandatory |
| Isolation | ERG 154: isolate spill 25-50m; if tank/rail car involved in fire, isolate 800m all directions |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury
- Contact with molten substance may cause severe burns to skin and eyes.
- Avoid any skin contact.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental
- Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive
- Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.).
- Corrosives in contact with metals may evolve flammable hydrogen gas.
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 2693 — Bisulphites, aqueous solution, n.o.s. HAZMAT RADIO NOTE — UN 2693
Product: Bisulphites, aqueous solution, n.o.s.
Class 8 / Corrosive / ERG 154
PPE: Level B minimum; chemical-resistant suit, gloves, boots; SCBA for vapor exposure; face shield and eye protection mandatory
ISOLATION: ERG 154: isolate spill 25-50m; 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 2693 — Bisulphites, aqueous solution, n.o.s.
Class: 8 | Placard: Corrosive | ERG Guide: 154
Appearance: Clear to yellowish aqueous solution with a pungent, sharp sulfur dioxide odor. Liquid at room temperature with acidic pH.
Water Reactivity: Miscible with water; may release sulfur dioxide gas upon dilution or heating
Extinguishing: Water spray, fog, or regular foam acceptable for neighboring fires
PPE: Level B minimum; chemical-resistant suit, gloves, boots; SCBA for vapor exposure; face shield and eye protection mandatory
Isolation: ERG 154: isolate spill 25-50m; if tank/rail car involved in fire, isolate 800m all directions
— Key Hazards —
• TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury
• Contact with molten substance may cause severe burns to skin and eyes.
• Avoid any skin contact.
— 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/2693 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2693 Bisulphites, aqueous solution, n.o.s. Cls8 ERG154 | allfirefighter.com/hazmat/un/2693SMS / 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/2693
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FAQ
TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Corrosives in contact with metals may evolve flammable hydrogen gas.
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; chemical-resistant suit, gloves, boots; SCBA for vapor exposure; face shield and eye protection mandatory
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 154 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.