EMT · Scene Size-Up and Safety · 6 min read
Hazardous Materials Recognition and Decontamination Needs
- Identify hazardous materials releases and high-risk scenes while maintaining safe positioning and staging protocols.
- Interpret transport placards, facility warning diamonds, and reference resources to determine appropriate initial protective actions.
- Explain the operational control zones, decontamination procedures, vehicle protection rules, and hospital pre-notification requirements.
Hazardous Materials Recognition and Initial Scene Safety
A hazardous material is any substance that poses an unreasonable risk to health, safety, or property. Emergency Medical Technicians are typically trained to the First Responder Awareness level of hazardous materials response. The primary responsibility of an EMT at a hazardous materials incident is personal safety and scene safety. Responders cannot protect or treat patients if they become casualties themselves.
When approaching a suspected hazardous materials release, EMTs should stop at a safe distance and, when possible, position the ambulance uphill, upwind, and upstream. Topography and wind direction dictate where dangerous liquids and vapor clouds travel. EMTs should stage at a safe distance and use binoculars to read placards if doing so helps them avoid approaching the hazard.
Certain locations carry an increased likelihood of chemical emergencies. Facilities such as industrial plants, hardware stores, agricultural sites, and laboratories have a high risk of hazmat incidents. Container shapes, such as pressurized cylinders and rail tank cars, can provide clues that hazardous materials may be present even before any release is confirmed.
Environmental clues can also indicate an active chemical release. Dead vegetation, dead animals, discolored soil, and visible vapor clouds are environmental signs of a hazardous materials release. In evaluating these scenes, EMTs must never rely on senses such as smell, taste, or touch to identify a hazardous material.
Common mistakes
- Entering the hot zone to deliver emergency care without specialized hazardous materials technician training and equipment.
- Using senses like smell, taste, or touch to identify a substance rather than relying on placards, container shapes, and reference guides.
- Applying water immediately to dry chemical powders or water-reactive substances without first brushing away powder or consulting specialist guidance.
- Placing a chemically contaminated patient into an ambulance wrapped in plastic sheeting instead of completing appropriate decontamination.
Key points
- An EMT's primary responsibility at a hazardous materials incident is personal and scene safety, operating at the First Responder Awareness level.
- Position the ambulance uphill, upwind, and upstream at a safe distance, and use binoculars to identify placards and container shapes.
- Most DOT placards indicate a hazard class and may display a UN identification number, but a DANGEROUS placard can identify a mixed load without specifying a class; NFPA 704 rates health, flammability, and instability from 0 to 4, while its white quadrant shows special hazards; the ERG guides initial actions, with Guide 111 used when a more specific guide cannot be selected for unidentified cargo.
- Scenes are divided into hot (exclusion), warm (contamination reduction), and cold (support) zones; EMTs provide care in the cold zone after appropriate decontamination.
- Decontamination limits secondary contamination; removing contaminated outer clothing can remove much of a patient’s surface contamination, often cited as approximately 80 to 90 percent, but further decontamination may be needed.
- Brush away dry powders before washing, use copious low-pressure water for liquids, avoid water on water-reactive substances, and continuously flush contaminated eyes with clean water or normal saline.
- Do not place a patient with residual chemical contamination in an ambulance until appropriate decontamination is completed; notify the receiving hospital early, and do not use plastic sheeting as a substitute for decontamination.
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