☣️ UN 2439 • CLASS 8
Sodium hydrogendifluoride
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 2439
Class: 8
Placard type: Corrosive
ERG: Guide 154 (check current ERG)
Isolation: ERG 154: Initial isolation 50m in all directions; spill: 150m downwind day/300m night; fire: 800m in all directions
Chemical & Response Details
| Also known as | Sodium bifluorideSodium hydrogen fluorideSodium acid fluorideNaHF2 |
| CAS Number | 1333-83-1 |
| Appearance | White crystalline solid or powder. Odorless or slight acidic odor. Stable at room temperature. |
| Flash Point | Not applicable (non-combustible solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Dissolves in water producing corrosive and toxic hydrogen fluoride solution |
| Extinguishing | Dry chemical, soda ash, lime; avoid direct water application on material |
| PPE | ⚠️ Level A or B minimum; SCBA required; full chemical-resistant suit; neoprene or butyl rubber gloves |
| Isolation | ERG 154: Initial isolation 50m in all directions; spill: 150m downwind day/300m night; fire: 800m in 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 2439 — Sodium hydrogendifluoride HAZMAT RADIO NOTE — UN 2439
Product: Sodium hydrogendifluoride
Class 8 / Corrosive / ERG 154
PPE: Level A or B minimum; SCBA required; full chemical-resistant suit; neoprene or butyl rubber gloves
ISOLATION: ERG 154: Initial isolation 50m in all directions; spill: 150m downwind day/300m night; fire: 800m in 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 2439 — Sodium hydrogendifluoride
Class: 8 | Placard: Corrosive | ERG Guide: 154
Appearance: White crystalline solid or powder. Odorless or slight acidic odor. Stable at room temperature.
Water Reactivity: Dissolves in water producing corrosive and toxic hydrogen fluoride solution
Extinguishing: Dry chemical, soda ash, lime; avoid direct water application on material
PPE: Level A or B minimum; SCBA required; full chemical-resistant suit; neoprene or butyl rubber gloves
Isolation: ERG 154: Initial isolation 50m in all directions; spill: 150m downwind day/300m night; fire: 800m in 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/2439 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2439 Sodium hydrogendifluoride Cls8 ERG154 | allfirefighter.com/hazmat/un/2439SMS / 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/2439
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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 A or B minimum; SCBA required; full chemical-resistant suit; neoprene or butyl rubber gloves
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.