☣️ UN 1674 • CLASS 6
UN 1674 — Phenylmercuric acetate
Placard: Toxic. ERG Guide 151. 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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UN 1674 Quick Details
UN 1674
Product name: Phenylmercuric acetate
DOT Class: 6
Placard type: Toxic
ERG Guide: 151 (check current ERG)
Initial isolation: ERG 151: isolate spill/leak area immediately for at least 25-50m in all directions; if large spill isolate 100m; evacuate downwind areas if airborne dust
Common Hazards of UN 1674
- Highly toxic, may be fatal if inhaled, ingested or absorbed through skin.
- 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
- Containers may explode when heated.
- Runoff may pollute waterways.
Chemical Identity & Physical Properties
| Also known as | PMAPhenylmercury acetateMercuric acetate phenylPhenylmercuric monoacetateAcetoxyphenylmercury |
| CAS Number | 62-38-4 |
| Appearance | White to cream-colored crystalline powder or prisms. Practically odorless. Solid at room temperature. |
| Flash Point | Not applicable (non-flammable solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid with negligible vapor pressure) |
| Water Reactivity | Slightly soluble in water; no violent reaction but may slowly hydrolyze |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1674
Extinguishing Media
Dry chemical, CO2, or water spray for surrounding fires; avoid creating dust
PPE Requirements
⚠️ Level B minimum with full-face SCBA; impervious gloves and suit required; prevent all skin contact due to absorption hazard
Isolation & Evacuation
ERG 151: isolate spill/leak area immediately for at least 25-50m in all directions; if large spill isolate 100m; evacuate downwind areas if airborne dust
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 151).
First Actions for a UN 1674 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.
- 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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📋 Copy & Share Field Card
UN 1674 — Phenylmercuric acetateHAZMAT RADIO NOTE — UN 1674
Product: Phenylmercuric acetate
Class 6 / Toxic / ERG 151
PPE: Level B minimum with full-face SCBA; impervious gloves and suit required; prevent all skin contact due to absorption hazard
ISOLATION: ERG 151: isolate spill/leak area immediately for at least 25-50m in all directions; if large spill isolate 100m; evacuate downwind areas if airborne dust
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 1674 — Phenylmercuric acetate
Class: 6 | Placard: Toxic | ERG Guide: 151
Appearance: White to cream-colored crystalline powder or prisms. Practically odorless. Solid at room temperature.
Water Reactivity: Slightly soluble in water; no violent reaction but may slowly hydrolyze
Extinguishing: Dry chemical, CO2, or water spray for surrounding fires; avoid creating dust
PPE: Level B minimum with full-face SCBA; impervious gloves and suit required; prevent all skin contact due to absorption hazard
Isolation: ERG 151: isolate spill/leak area immediately for at least 25-50m in all directions; if large spill isolate 100m; evacuate downwind areas if airborne dust
— Key Hazards —
• Highly toxic, may be fatal if inhaled, ingested or absorbed through skin.
• Avoid any skin contact.
• Fire may produce irritating, corrosive and/or toxic gases.
— 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.
• Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
SOURCE: allfirefighter.com/hazmat/un/1674 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1674 Phenylmercuric acetate Cls6 ERG151 | ERG 151: isolate spill/leak area immediately for at least 25-50m in all directio | allfirefighter.com/hazmat/un/1674SMS / 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/1674
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Frequently Asked Questions about UN 1674
Highly toxic, may be fatal if inhaled, ingested or absorbed through skin. 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 Containers may explode when heated. Runoff may pollute waterways.
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 with full-face SCBA; impervious gloves and suit required; prevent all skin contact due to absorption hazard
Water reactivity: Slightly soluble in water; no violent reaction but may slowly hydrolyze. Recommended extinguishing: Dry chemical, CO2, or water spray for surrounding fires; avoid creating dust.
ERG Guide 151 recommendation: ERG 151: isolate spill/leak area immediately for at least 25-50m in all directions; if large spill isolate 100m; evacuate downwind areas if airborne dust
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 151 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.