Chapter 13 Flashcards
Operations level responders with mission specific product control training are able to
Perform their duties with limited risk of exposure at hazmat incident
Flammable and combustible liquids control consideration (5)
Structural firefighters protective clothing can absorb flammable and combustible liquids which can later ignite if exposed to an ignition source
Vapors from flammable and combustible liquids are usually heavier than air
Flammable and combustible liuids are typically lighter then water and if so will float on the surface of water
Flammable and combustible liquids are Class b materials, water is an ineffective extinguishing agent
Flammable and combustible liquids vapors may be toxic for example benzene is carcinogen
Hazardous materials technicians and specialists perform
Most offensive leak control tactics
Operations responders can take offensive actions with these 3 fuels provided they have appropriate training procedures, equipment and PPE
Gasoline,
Diesel,
LPG
Cargo Tank Truck shutoff devices locations may very but often found
Located behind the drivers side cab
MC331 may also have ______ shutdown device
Electronically operated and can be operated 150 feet away
MC 306 /DOT 406 and MC 307 /DOT 407 have emergency shutoff device on
left front corner of the tank behind the driver compartment
MC 323/dog 412 typically
dont have shut off devices
High pressure cryogenic intermodal containers will have
Emergency shutoffs for the bottom internal valve
Spill control is not restricted to controlling liquids, responders may also need to confine dusts, vapors, and gases with the following (5)
Protective covering consisting of a fine spray of water
Layers of earth
Salvage covers
Plastic sheets
Foam blankets on liquids
Strategically placed water streams can direct absorb dilute or move gases reference sources and trainer information can provide the proper procedures for confining gases. the following dictate the type and effectiveness of confinement efforts (7)
Material type
Rate of release
Speed of spread
Number of responder available
Tools and equipment needed
Weather
Topography
Defensive spill control tactics that confine hazardous materials include the following (5)
Absorption
Blanketing/Covering
Vapor Suppression
Adsorption
Dam Dike, Divert and retain
Some defensive spill control tactics include diluting the concentration or changing its physical state of matter of hazard. these 7 tactics include the following
Dilution
Dispersion
Solidification
Ventilation
Dissolution
Neutralization
Vapor Dispersion
Absorption is
like a sponge soaking up water retains a liquid hazardous material in some other material, the bulk of the liquid being absorbed enter the cell structure of the absorbing medium.
5 Common Absorption materials
Sawdust
Clays
Charcoal
Polyolefin type fibers
Specially designed absorbent pads, pillows, booms, and socks
Adsorption is
Differs from absorption in that molecules of the liquid hazardous material physically adhere to the adsorbent material rather then being absorbed into the inner spaces
2 Common Adsorption materials
Activated charcoal
Carbon
For Blanketing or covering solids such as powders and dust the following 4 tools are used
Tarps
Salvage covers
Plastic sheeting
Other materials including foam
Blanketing / covering can also be used in the following situations (3)
At radiological and biological incident as a form of temporary mitigation
At liquified gas leaks to cause the released material to auto refrigerate beneather the tarp or covering
As a temporary option to covering openings of some liquid containers with plastic sheets or tarps to confine vapors
Two Main types of dams
Containment
underflow and overflow
Underflow and overflow dam
permits surface water or runoff to pass either under or over the dam while holding back the hazardous material
Underflow dam retains hazardous materials that are
Lighter than water
Overflow dam retains hazardous materials that are
heavier than water
Retaining is
Holding or containing a liquid in a area until it can be absorbed, neutralized or removed, and is often used as a longer term solution
Dilutions is
The application of water to water soluble material to reduce the hazard
Dispersion is
Involves breaking up or dispersing a hazardous material that has spilled on a solid or liquid surface with both chemical or biological agents
Neutralization is
involves raising or lowering the ph of corrosive materials to render them neutral
Vapor Dispersion
Uses water spray to direct or influence the course of airborne hazardous materials
Vapor Suppression
is the action taken to reduce the emission of vapors, firefighting foams are effective on spills of flammable and combutible liquids if the foam concentrate is compatible with the material
Vapor Suppression
is the action taken to reduce the emission of vapors, firefighting foams are effective on spills of flammable and combustible liquids if the foam concentrate is compatible with the material
Foam Concentrates are divided into two general categories based on the classification
Class A fuel foams = Ordinary combustibles
Class B fuel foam= For Flammable and combustible liquids
To produce high quality foam four elements are necessary
Foam Concentrate
Water
Air
Mechanical Agitation
5 other points to consider when using foam for vapor suppression include
Do not use water streams in conjunction with the application of foam, water destory s and washes away foam blankets
Ensure that a material is below its boiling point, foam cannot seal vapors of boiling liquids
Dot not rely on the film that precedes the foam blanket it is not reliable vapor suppressant
Reapply aerated foam periodically until the foam completely overs the spill
Ensure Foam concentrate is above freezing point
Look for these 4 sets of letters before the name on the foam concentrate container
ARC- Alcohol resistand concentrate
PSL- Polar solvent liquid
ATC- Alcohol type concentrate to use on polar solvent liquids
F3- Flurine free foams for flammable hydrocarbon liquid fires
Drainage time is
The time required for one-fourth (25 percent or one quater) of the total liquid solution to drain from the foam
Expansion ration is
the volume of finished foam that results from a unit volume of foam solution
Responders should consider may factors at hazardous materials incident where flammable or combustible liquids are present or burning including (3)
Where vapors may be present or traveling
Where and what possible ignition sources are present
Whether to extinguish the fire and how
Responders should consider withdrawal as potentially safest tactical option due to conditions such as the following (3)
A threat of catastrophic container failure
Boiling liquid expanding vapor explosion BLEVE or other explosion potential
The resources needed to control the incident are unavailable
If inital water streams will not cool both the tank and exposures given priority to
the involved container
Most potassium based dry chemical agents such as purple k are compatible with foam but do not use the 2 following agents
ABC that use monoammonium phosphate based dry chemical which is yellow in color
BC that use sodium bicarbonate which is blue in color
the most common cause of a BLEVE is
When flames contact the tank shell above the liquid level and the tank shell itself has overheated
When attacking a tank cars that may BLEVE apply
continual water at minimum rate of 500 GPM to the upper portions of the tank
Do not extinguis gas fed fires burning around the relief valves or piping unless
Turning off the supply can stop the leaking product
4 Variety of materials are loosely categorized as flammable solids
Metal Powders
Readily combustible solids that ignite by friction
Self reactive materials that undergo a strong exothermic decomposition
Explosives’ that are wetted to suppress their explosive properties
