UN 1748 — Calcium hypochlorite mixture, dry, with more than 39% available chlorine (8.8% available oxygen)
Placard: Oxidizer. ERG Guide 140. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1748 is Calcium hypochlorite mixture, dry, with more than 39% available chlorine (8.8% available oxygen), a Class 5 oxidizer assigned to ERG Guide 140. It can accelerate burning and may release chlorine-type gases if heated, contaminated, wetted or acidified.
Hazard overview: UN 1748 presents oxidizer fire acceleration, decomposition, chlorine-type gas and contaminated-runoff hazards. Keep it away from fuels, organics, acids, ammonia compounds and reducing agents.
Response guidance: For a UN 1748 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 140. Establish incident command, isolate the area, stay upwind, prevent incompatible contact, control runoff and choose entry or fire-control actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1748 should emphasize oxidizer fire acceleration, chlorine-type gas release, contamination with organics/acids/ammonia, dust control and runoff containment. Use ERG 140, SDS and local SOP.
Regulatory context: Calcium hypochlorite mixture, dry, with more than 39% available chlorine (8.8% available oxygen) is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, waste handling, storage and environmental requirements may vary by concentration, formulation, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Calcium hypochlorite mixture, dry, with more than 39% available chlorine (8.8% available oxygen) should be stored dry in compatible oxidizer storage away from acids, ammonia compounds, fuels, organics, reducing agents, heat and contamination. Keep containers closed, separated from combustible packaging and protected from moisture.
UN 1748 Quick Details
Common Hazards of UN 1748
- OXIDIZER; accelerates burning and can intensify fires involving combustibles.
- May decompose violently when heated, contaminated or mixed with incompatible materials.
- Can react dangerously with fuels, organics, ammonia compounds, acids or reducing agents.
- Acid contact or decomposition may release chlorine-type toxic gases.
- Dust or solution can burn or irritate eyes, skin and respiratory tissue.
- Containers may rupture or explode when heated.
- Runoff may spread oxidizing and corrosive contamination.
Chemical Identity & Physical Properties
White granular solid or powder with a strong chlorine-like odor. May appear slightly yellow or gray depending on purity.
| Also known as | Calcium oxychlorideChlorinated limeHTHLosantinPittchlorBleaching powder |
| CAS Number | 7778-54-3 |
| Appearance | White granular solid or powder with a strong chlorine-like odor. May appear slightly yellow or gray depending on purity. |
| Flash Point | Not applicable (oxidizing solid, non-flammable but supports combustion) |
| Boiling Point | Not applicable (decomposes at approximately 180C/356F) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Reacts with water releasing oxygen and heat; may produce chlorine gas when wet or in acidic conditions |
Fireground Response Guidance — UN 1748
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for dust, chlorine-type vapor, fire or confined-space exposure. Wear chemical-resistant gloves, eye/face protection and protective clothing selected from SDS; avoid contaminated dust and runoff.
Isolation & Evacuation
First Actions for a UN 1748 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Avoid breathing vapors, fumes, dust, mist or gas and avoid skin or eye contact.
- Keep fuels, organics, reducing agents and contaminated absorbents away from the material.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Ventilate closed spaces before entering, but only if properly trained, equipped, monitored and authorized by incident command.
- Isolate the spill or leak area and expand the perimeter if vapor, gas, dust, fire involvement, water reaction or unknown concentration is present.
- Use ERG Guide 140, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1748 — Calcium hypochlorite mixture, dry, withUse for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.