☣️ UN 1740 • CLASS 8
UN 1740 — Hydrogendifluorides, solid, n.o.s.
Placard: Corrosive. ERG Guide 154. 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 1740 Quick Details
UN 1740
Product name: Hydrogendifluorides, solid, n.o.s.
DOT Class: 8
Placard type: Corrosive
ERG Guide: 154 (check current ERG)
Initial isolation: ERG 154: isolate spill area at least 25m in all directions; evacuate 800m downwind if large spill or fire involves material
Common Hazards of UN 1740
- 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.
Chemical Identity & Physical Properties
| Also known as | hydrogen difluorideacid fluoridebifluoride saltsacidic fluoride compoundsHF2- compounds |
| Appearance | White to colorless crystalline solids or powders with no distinct odor or a slight acidic odor. Corrosive in nature and may be hygroscopic. |
| Flash Point | Not applicable (non-flammable solid) |
| Boiling Point | Decomposes before boiling, typically above 200C (392F) depending on specific compound |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Reacts with water to release hydrofluoric acid (HF) fumes, highly toxic and corrosive |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1740
Extinguishing Media
Dry chemical, soda ash, lime for neutralization; avoid water spray due to HF generation
PPE Requirements
⚠️ Level A or B required; full chemical-resistant suit, SCBA, acid-resistant gloves and boots mandatory; protect against HF exposure
Isolation & Evacuation
ERG 154: isolate spill area at least 25m in all directions; evacuate 800m downwind if large spill or fire involves material
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 154).
First Actions for a UN 1740 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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UN 1740 — Hydrogendifluorides, solid, n.o.s.HAZMAT RADIO NOTE — UN 1740
Product: Hydrogendifluorides, solid, n.o.s.
Class 8 / Corrosive / ERG 154
PPE: Level A or B required; full chemical-resistant suit, SCBA, acid-resistant gloves and boots mandatory; protect against HF exposure
ISOLATION: ERG 154: isolate spill area at least 25m in all directions; evacuate 800m downwind if large spill or fire involves material
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 1740 — Hydrogendifluorides, solid, n.o.s.
Class: 8 | Placard: Corrosive | ERG Guide: 154
Appearance: White to colorless crystalline solids or powders with no distinct odor or a slight acidic odor. Corrosive in nature and may be hygroscopic.
Water Reactivity: Reacts with water to release hydrofluoric acid (HF) fumes, highly toxic and corrosive
Extinguishing: Dry chemical, soda ash, lime for neutralization; avoid water spray due to HF generation
PPE: Level A or B required; full chemical-resistant suit, SCBA, acid-resistant gloves and boots mandatory; protect against HF exposure
Isolation: ERG 154: isolate spill area at least 25m in all directions; evacuate 800m downwind if large spill or fire involves material
— 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/1740 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1740 Hydrogendifluorides, solid, n.o.s. Cls8 ERG154 | allfirefighter.com/hazmat/un/1740SMS / 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/1740
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Frequently Asked Questions about UN 1740
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 A or B required; full chemical-resistant suit, SCBA, acid-resistant gloves and boots mandatory; protect against HF exposure
Water reactivity: Reacts with water to release hydrofluoric acid (HF) fumes, highly toxic and corrosive. Recommended extinguishing: Dry chemical, soda ash, lime for neutralization; avoid water spray due to HF generation.
ERG Guide 154 recommendation: ERG 154: isolate spill area at least 25m in all directions; evacuate 800m downwind if large spill or fire involves material
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.