Chapter 5 Flashcards
The first step in mitigating or solving any hazmat incident is understanding the problem within the framework of incident priorities, ims, and predetermined procedures.
predetermined procedures
Skillful incident commanders synthesize information quickly in order to form a clear picture of the incident.
synthesize
Ongoing evaluation of influential factors at the scene of an incident.
Size-up
Model used to describe how hazardous materials are accidentally released from their containers and how they behave after the release.
General emergency behavior model
Stress - The container undergoes physical, thermal, or other types of damage that reduces its ability to function and leads to breach or failure.
Stress
Breach - The container becomes open to the environment.
Breach
Release - When a container breaches or fails, contents, stored energy, and pieces of the container may be expelled into the environment.
Release
Dispersion/engulf - This occurs as the hazardous material inside the container and any stored energy release and move away from the container.
Dispersion/engulf
Patterns of dispersion are influenced by chemistry, physics, environment factors, and the chemical and physical characteristics of the product.
physics
Exposure/contact - Anything that is in the area of the release is exposed to the hazardous material.
Exposure/contact
Depending on the container, hazardous material, and energy involved, exposures may result in harm or damage.
Harm
Container stress is caused by thermal energy, chemical energy, and mechanical energy.
mechanical energy
Thermal stress may increase internal pressure and reduce container shell integrity, resulting in sudden failure.
Thermal stress
The appearance of frost is an indicator that a container is under thermal stress.
frost
Uncontrolled reactions/interactions of the container and its contents.
Chemical energy
Physical application of energy could result in container, attachment damage.
Mechanical energy
Chemical reactions may cause a container to bulge, which is a sign of significant stress.
bulge
Mechanical energy can crush or damage a container.
crush
The material’s state of matter will affect the stress experienced by containers.
state of matter
Most solids containers will be damaged via mechanical stressors rather than the physical properties of the materials contained in them.
mechanical stressors
Limits of recovery - A containers design strength or ability to hold contents at pressure.
Limits of recovery
When a container is stressed beyond its Limits of recovery, it opens or breaches and releases its contents.
Limits of recovery
Breach - To make an opening in a structural obstacle without compromising the overall integrity of the wall to allow access into or out of a structure for rescue.
breach
Detonation - Instantaneous and explosive release of stored chemical energy of a hazardous material.
Detonation
Violent rupture - Immediate release of chemical or mechanical energy caused by runaway cracks.
Violent rupture
Rapid relief - Fast release of a pressurized hazardous material through properly operating safety devices.
Rapid relief
Spill/leak - Slow release of a hazardous material under atmospheric or head pressure through holes, rips, tears, or usual openings/attachments.
Spill/leak
Head pressure - Pressure exerted by a stationary column of water, directly proportional to the height of the column.
Head pressure
The dispersion of material is sometimes referred to as engulfment.
engulfment
rapid relief occurs when pressurized hazmat is released through properly operating safety devices.
rapid relief
When evaluating release potential, remember the total amount of product in the container.
release potential
Engulfment occurs when a product disperses, forming a danger zone.
danger zone
Hemispheric release - Semicircular or dome shaped pattern of airborne hazardous material that is still partially in contact with the ground or water.
Hemispheric release
Cloud - Ball shaped pattern of an airborne hazardous material where the material has collectively risen above the ground or water.
Cloud
Plume - Irregularly shaped pattern of an airborne hazardous material where wind and/or topography influence the downrange course from the point of release.
Plume
A hemispheric release generally results from a rapid release of energy.
hemispheric release
Solid cloud cover can reflect the detonation shock wave, increasing the explosion impact.
shock wave
Dispersion of a plume is affected by vapor density and terrain, as well as wind speed and direction.
vapor density, terrain
Cone - Triangular shaped pattern of an airborne hazardous material release with a point source at the breach and wide base downrange.
Cone
stream - Surface following pattern of liquid hazardous material that is affected by gravity and topographical contours.
stream
Pool - Three dimensional slow flowing liquid dispersion.
Pool