☣️ UN 2784 • CLASS 3

UN 2784 — Organophosphorus pesticide, liquid, flammable, poisonous

Placard: Flammable. ERG Guide 131. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.

🚒☣️
⚠️ Verification required: Broad or variable material category; verify exact product, SDS and shipping papers.
⚠️ 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.

Organophosphorus pesticide, liquid, flammable, poisonous is a variable pesticide formulation shipped as a toxic flammable liquid. The active ingredient and solvent system must be verified before responders choose final tactics.

Hazard overview: Organophosphorus pesticide may be highly toxic by inhalation, ingestion or skin absorption. Liquid or dust contact can irritate or burn skin and eyes depending on the formulation. Fire or heating may produce irritating, toxic and corrosive decomposition products.

Response guidance: For a Organophosphorus pesticide, liquid, flammable, poisonous release, isolate the area, remove ignition sources if present, and keep runoff out of drains. Responders should use SCBA with chemical-resistant clothing and base tactics on SDS, shipping papers and monitoring.

Firefighter training notes: Train responders to identify the UN number, product name, placard, container type and exposure route before committing personnel to the hot zone.

Regulatory context: Use the proper DOT shipping description, ERG guide, SDS and site-specific response plan; do not substitute this summary for regulatory compliance.

Storage & handling: Store away from heat, sparks, oxidizers, drains and food/feed materials; segregate by pesticide formulation and SDS requirements.

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UN 2784 Quick Details

UN 2784
Product name: Organophosphorus pesticide, liquid, flammable, poisonous
DOT Class: 3
Placard type: Flammable
ERG Guide: 131 (check current ERG)
Initial isolation: Use ERG Guide 131 initial isolation, then adjust with SDS, shipping papers, wind, monitoring and amount released.

Common Hazards of UN 2784

  • Organophosphorus pesticide may be highly toxic by inhalation, ingestion or skin absorption.
  • Liquid or dust contact can irritate or burn skin and eyes depending on the formulation.
  • Fire or heating may produce irritating, toxic and corrosive decomposition products.
  • Runoff, wash water and contaminated absorbent can carry pesticide into drains or waterways.
  • Exact active ingredient, solvent carrier and concentration must be verified from SDS and shipping papers.
  • Flammable solvent vapors may form explosive mixtures with air.
  • Vapors can travel to ignition sources and flash back, especially in low or confined areas.
  • Containers may rupture or explode when heated.

Chemical Identity & Physical Properties

Typically an oily or viscous liquid, color varies by formulation (colorless to amber or brown). Odor ranges from mild to garlic-like or sulfurous depending on specific compound. Liquid at room temperature.

Also known asOrganophosphate pesticide liquidOP pesticide flammablePhosphoric acid ester pesticideOrganophosphorus insecticide liquid
AppearanceTypically an oily or viscous liquid, color varies by formulation (colorless to amber or brown). Odor ranges from mild to garlic-like or sulfurous depending on specific compound. Liquid at room temperature.
Flash PointVaries by formulation, typically -18C to 61C (0F to 142F) — flammable
Boiling PointVaries by compound, typically 100C to 300C (212F to 572F)
Vapor DensityGreater than 1 (heavier than air)
Water ReactivityNo violent water reaction is expected, but water can spread toxic pesticide contamination; verify formulation-specific SDS.
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 2784

Extinguishing Media

Alcohol-resistant foam, dry chemical or CO2 are preferred for flammable solvent formulations; water spray may cool containers.

PPE Requirements

⚠️ SCBA with Level A or B chemical protection may be required; avoid all skin contact and use product-specific pesticide decon.

Level A or B with SCBA required; full chemical-resistant suit; butyl or nitrile gloves; decontamination essential due to skin absorption risk

Isolation & Evacuation

Use ERG Guide 131 initial isolation, then adjust with SDS, shipping papers, wind, monitoring and amount released.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 131).

First Actions for a UN 2784 Incident

  • Call 911 and the emergency response number shown on the shipping papers.
  • Keep unauthorized personnel away and establish an initial isolation perimeter.
  • Stay upwind, uphill and upstream; avoid low areas where vapors or runoff may collect.
  • Avoid breathing vapors, dust, mist or smoke and prevent skin and eye contact.
  • Do not touch damaged packages, leaking containers or spilled material without appropriate PPE.
  • Eliminate ignition sources; stop traffic, engines, smoking and open flames if it can be done safely.
  • Ventilate confined spaces only when responders are trained, equipped and monitoring conditions.
  • Use ERG, SDS, shipping papers and air monitoring to set final isolation, evacuation and decon actions.
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📋 Copy & Share Field Card

UN 2784 — Organophosphorus pesticide, liquid, flam
HAZMAT RADIO NOTE — UN 2784 Product: Organophosphorus pesticide, liquid, flammable, poisonous Class 3 / Flammable / ERG 131 PPE: SCBA with Level A or B chemical protection may be required; avoid all skin contact and use product-specific pesticide decon. ISOLATION: Use ERG Guide 131 initial isolation, then adjust with SDS, shipping papers, wind, monitoring and amount released. 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 2784 — Organophosphorus pesticide, liquid, flammable, poisonous Class: 3 | Placard: Flammable | ERG Guide: 131 Appearance: Typically an oily or viscous liquid, color varies by formulation (colorless to amber or brown). Odor ranges from mild to garlic-like or sulfurous depending on specific compound. Liquid at room temperature. Water Reactivity: No violent water reaction is expected, but water can spread toxic pesticide contamination; verify formulation-specific SDS. Extinguishing: Alcohol-resistant foam, dry chemical or CO2 are preferred for flammable solvent formulations; water spray may cool containers. PPE: SCBA with Level A or B chemical protection may be required; avoid all skin contact and use product-specific pesticide decon. Isolation: Use ERG Guide 131 initial isolation, then adjust with SDS, shipping papers, wind, monitoring and amount released. — Key Hazards — • Organophosphorus pesticide may be highly toxic by inhalation, ingestion or skin absorption. • Liquid or dust contact can irritate or burn skin and eyes depending on the formulation. • Fire or heating may produce irritating, toxic and corrosive decomposition products. — First Actions — • Call 911 and the emergency response number shown on the shipping papers. • Keep unauthorized personnel away and establish an initial isolation perimeter. • Stay upwind, uphill and upstream; avoid low areas where vapors or runoff may collect. • Avoid breathing vapors, dust, mist or smoke and prevent skin and eye contact. SOURCE: allfirefighter.com/hazmat/un/organophosphorus-pesticide-liquid-flammable-un-2784 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.

SMS (short)
UN2784 Organophosphorus pesticide, liquid, flammable, poisonous Cls3 ERG131 | allfirefighter.com/hazmat/un/organophosphorus-pesticide-liquid-flammable-un-2784SMS / 160 CHAR

Use for: Quick text to command or incoming units. Fits in a single SMS.

Open in Messages WhatsApp
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/organophosphorus-pesticide-liquid-flammable-un-2784

Related UN Numbers in Class 3

Open Class Guide →Hazmat Hub →
UN 1088UN 1089UN 1090UN 1091UN 1104UN 1105UN 1106UN 1107UN 1108UN 1109UN 1110UN 1111
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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Frequently Asked Questions about UN 2784

UN 2784 covers Organophosphorus pesticide, liquid, flammable, poisonous. Use the shipping papers and SDS to confirm the exact product before choosing tactics.

Yes. Exposure may be harmful or fatal by inhalation, ingestion or skin absorption, depending on concentration and formulation.

Yes. Keep ignition sources away because vapors can ignite and flash back from low or confined areas.

No violent water reaction is expected, but water can spread contamination and does not reduce toxicity.

Alcohol-resistant foam, dry chemical, CO2; avoid water jets but water spray may reduce vapors

Use SCBA and chemical-resistant protective clothing. Level A or B may be needed when vapors, splash risk or product identity is uncertain.

This entry can cover different formulations, active ingredients and solvents, so response details may change by product.
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.
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