Chapter 4 Flashcards
Operations level responders need to know how hazardous materials:
Behave in addition to the symptoms and effects of an exposure.
Pg 192
Matter is found in three states:
Gas,liquid, solid
P 193
Gases are difficult to contain for mitigation purposes and will move according to:
Prevailing wind and air movement
Pg 193
Liquids will flow or pool according to:
Surface contours and topography permitting opportunities for containment of confinement
Pg 193
Solids may be moved by exterior forces but will typically remain in place unless:
Acted upon
The majority of haz mat incidents involve materials that are:
Flammable
Pg 194
Flash point:
The minimum temperature at which a liquid or volatile solid gives of sufficient vapors to form an ignitable mixture with air near its surface. At this temp the vapors will flash but will not continue to burn
Pg 194
Fire point:
The temperature at which enough vapor are given off to support continuous burning
Pg 196
Autoignition temperature:
The minimum temp to which the fuel in air must be heated to initiate self sustained combustion without initiation from an independent ignition source. This temperature is the point at which a fuel spontaneously ignites
Pg 197
Vapor pressure:
Pressure exerted by a saturated vapor above its own liquid in a closed container or more simply it is the pressure produced or exerted by the vapors released by a liquid
The higher the temp the higher the vapor pressure
Pg 200
The lower the boiling point of a substance,
The higher its vapor pressure will be
Pg 200
Boiling point:
The temp at which the vapor pressure of a liquid is equal to or greater than atmospheric pressure
Pg 202
Melting point:
Temp at which a solid substance changes to a liquid state at normal atmospheric pressure
Pg 202
Freezing point:
The temp at which a liquid becomes a solid at normal atmospheric pressure
Pg 203
Vapor density:
The weight of a given volume of pure vapor or gas compared to the weight of an equal volume of dry air at the same temperature and pressure
Pg 204
Solubility in water:
Percentage of a material that will dissolve in water at ambient temperature. A substances solubility affects whether it mixes in water
Pg 205
Irritant agents that are water soluble usually cause:
Early upper respiratory tract irritation resulting in coughing and throat irritation
Pg 205
Partially water soluble chemicals penetrates into the:
Lower respiratory system causing delayed symptoms that include breathing difficulties pulmonary edema and coughing up blood
Pg 205
Miscible:
Two liquids that dissolve into each other.
Pg 205
Specific gravity:
The ratio of the density (heaviness) of a material to the density of some standard material at standard conditions of pressure and temperature
Pg 205
The persistence of a chemical is its ability to:
Remain in the environment
Pg 207
Reactivity of a substance:
Is its relative ability to undergo a chemical reaction with another material
Pg 207
Reactive materials commonly react vigorously or violently with:
Air, water, heat, each other or other materials
Pg 207
All reactions require some energy to get them started, which is commonly referred to as:
Activation energy
Pg 208
Strong oxidizers are materials that:
Encourage a strong reaction from reducing agents:
Pg 209
Materials that may undergo polymerization if subjected to heat or contamination are designated with a ______ in the blue and yellow sections of the ERG book
P
209
Inhibitors are materials that are:
Added to products that easily polymerize in order to control or prevent an undesired reaction
Pg209
In hazardous materials incidents the following sequences generally occurs:
Stress Reach Release Dispersion/engulf Exposure/contact Harm Pg 215
Container stress is classified as:
Stimulus causing strain(excessive tension or compression)
Pressure (force applied at right angles to a surface)
Deformity ( distortion by torque or twisting)
Pg 215
Almost 1/4 of all reported hazmat incidents are caused by:
Container failure
Pg 215
When evaluating container stress consider:
Type of container, type and amount of stress, and its potential duration
Pg 215
Thermal stress:
Excessive heat or cold causing intolerable expansion, contraction, weakening or consumption of the container an its parts
Pg 215
Chemical stress:
Uncontrolled reactions/ interactions of contents in the container and the container itself resulting in a sudden or long term deterioration of the container
Pg 215
Mechanical stress:
Physical application of energy resulting in container attachment damage
Pg 216
Breach:
When a container is stressed beyond its limits of recovery it opens or breaches and releases its contents
Pg 216
Disintegration breach:
Container suffers a general loss of integrity
Pg 216
Runaway cracking breach:
Crack develops in a container as a result of some type of damage which continues to grow rapidly breaking the container into two or more relatively large pieces
Pg 216
When a container fails three things may release:
The product, energy and the container
Pg 217
Releases are classified based on:
How fast they occur
Pg 217
Detonation release:
Instantaneous and explosive release of stored chemical energy of a hazardous material
Pg 217
Violent rupture release:
Immediate release of chemical or mechanical energy caused by runaway cracks. Usually occur in one second or less
Pg 217
Rapid relief release:
Fast release of a pressurized hazadous material through properly operating safety devices. Takes several seconds to several minutes
Pg 218
Spill/leak release:
Slow release of haz mat under atmospheric or head pressure through holes, rips, tears or usual openings. Several minutes to several days
Pg 218
Dispersion of the product, energy and container components depends on the:
Type of release as well as physical and chemical laws
Pg 218
Once a container has been compromised, the hazardous materials will be distributed over the surrounding area according to the following five factors:
Physical/chemical properties Prevailing weather conditions Local topography Duration of the release Control efforts of responders Pg 219
Hemispheric dispersion pattern:
Semicircular or dome shaped pattern of airborne hazardous material that is still partially in contact with the ground or water
Pg 219
Cloud dispersion pattern:
Ball shaped pattern of the airborne hazardous material where the material has collectively risen above the ground or water. Terrain or wind effects can transform a cloud into a plume
Pg 220
Plume dispersion:
Irregularly shaped pattern of an airborne hazardous material where wind and topography influence the downrange course from the point of release.
Pg 220
Dispersion of a plume is affected by:
Vapor density and terrain as well as wind speed and direction.
Pg 220
Cone release:
Triangular shaped pattern of a hazardous material with a point source at the breach and a wide base downrange
Pg 221
Stream dispersion:
Surface following pattern of liquid hazardous material that is affected by gravity and topographical contours
Pg 222
Pool dispersion:
Three dimensional slow flowing liquid dispersion. Liquids assume the shape of their container and pool in low areas
Pg 222
The health and pysical. Hazards that could cause harm in a hazardous materials incident are:
Thermal Mechanical Poisonous Corrosive Asphyxiation Radiation Biological Pg 225
Release time frames:
Immediate: milliseconds Short term: minutes hours Medium term: days weeks months Long term: years, generations Pg 224
