Chapter 2 Flashcards
What is the definition of Physical Changes?
A transformation in which a material changes its state of matter (ex. from a liquid to a solid)
(CHIEF CONCEPT) What is an important first step in understanding that hazards associated with any chemical?
Identifying the State of Matter, defining whether the substance is a solid, liquid or a gas
The State of Matter is
The physical state of the substance. A solid, liquid or a gas.
What is a critical step in comprehending the nature of a release?
Identifying the reason(s) why the container failed
What does BLEVE stand for?
Boiling Liquid Expanding Vapor Explosion
What is a BLEVE
Occurs when a pressurized liquefied materials inside a closed vessel are exposed to a source of high heat. Occurs if relief valve can’t contain the increased pressure.
What is expansion ratio?
The volume increase that occurs when a compressed liquefied gas material changes to a gas
What is chemical reactivity (chemical change)?
The ability of a substance to undergo a transformation at the molecular level, usually with a release of some form of energy
(CHIEF CONCEPTS) What are the critical characteristics of flammable liquids?
- Flash Point
- Ignition Temperature
- Flammable Range
What is flash point?
The minimum temperature at which a liquid or a solid releases sufficient vapor to form an ignitable mixture with air.
What is ignition temperature (autoignition)?
The minimum temperature at which a fuel, when heated, will ignite in the presence of air and continue to burn. The ignition temperature for gasoline is 475 Fahrenheit.
True or False: When a liquid fuel is heated beyond it’s initial ignition temperature, it will ignite without an external ignition source
True (ex. a pan full of cooking oil)
What is flammable range?
A fuel/air mixture, defined by upper and lower limits that reflects an amount of flammable vapor mixed with a given volume of air.
What is the flammable range of gasoline vapors?
1.4% to 7.6%
(TEST) What is a lower explosive limit (LEL)?
The minimum amount of gaseous fuel that must be present for the air/fuel mixture to be flammable/explosive
(TEST) What is an upper explosive limit (UEL)?
The maximum amount of gaseous fuel that can be present for the fuel/air mixture to be flammable/explosive
True or False: If a fuel/air mixture falls between the UEL and LEL, an ignition source is still needed for a flash fire to occur
True
True or False: The wider the flammable range, the more dangerous the material
True. Hydrogen is 4.0% to 75%, natural gas is 5% to 15%, and propane is 2.5% to 9.0%
What is vapor pressure?
The pressure associated with liquids held inside any type of closed container
What is the key point to understanding vapor pressure?
The vapor pressure released from the surface of any liquid needs to be contained in order to exert pressure
How is vapor pressure expressed?
In PSI, atmospheres (atm), torr, millimeters of mercury (mm Hg), or bar
What is boiling point?
Temperature at which a liquid will continually give off vapors and if boiling long enough, will turn completely into gas.
What is the boiling point of water?
212 F
What is fire point?
The temperature at which sustained combustion will occur.
How does fire point compare to flash point?
Fire point is usually only slightly higher than the flash point.
True or False: Solids and liquids do not burn
True, the gas or vapor they give off is what’s ignited
Will flammable liquids readily burn?
Yes
Are many flammable liquids toxic?
Yes
Do most flammable liquids give off vapors that are heavier or lighter than air?
Vapors that are heavier than air
Can flammable liquids mix with or be carried with air?
Yes
What is vapor density?
The weight of an airborne concentration of a vapor or gas as compared to an equal volume of dry air
What is the vapor density of air?
1.0
A substance that is heavier than air has a vapor density…
Greater than 1.0
A substance that is lighter than air has a vapor density….
Lower than 1.0
What is an example of a substance that is heavier than air?
Propane (1.51) or chlorine
What’s an example of a substance that is lighter than air
Hydrogen, acetylene, or natural gas
What does 4H MEDIC ANNA tell you?
What some of the lighter than air gases are
In the mnemonic device 4H MEDIC ANNA, what are the 4H’s?
- Hydrogen
- Helium
- Hydrogen Cyanide
- Hydrogen Fluoride
In the mnemonic device 4H MEDIC ANNA, what does MEDIC stand for?
M - Methane E- Ethylene D - Diborane I - Illuminating gas (methane/ethane mixture) C - Carbon monoxide (CO)
In the mnemonic device 4H MEDIC ANNA, What does ANNA stand for?
A - Ammonia
N - Neon
N - Nitrogen
A - Acetylene
What is specific gravity?
The weight of a liquid as compared to water
What is the specific gravity of water?
1.0
Most of what kind of liquids will float on water?
Flammable liquids
A specific gravity of less than 1 will….
Float on water
A specific gravity of greater than 1 will….
Sink in water
What is water solubility?
The ability of a substance to dissolve in water
What is the predominant agent used to extinguish a fire?
Water
Why is water not always the best and safest choice in a chemical emergency?
Because it is a very aggressive solvent and may react violently with certain substances
What may knock down vapor clowds?
Fog streams
What is Corrosivity (pH)
The ability of a material to cause damage (on contact) to skin, eyes, or other body parts
What 2 classes are corrosives put into?
Acids and bases
What is the range of the pH scale?
0-14
What is pH?
An expression of the amount of dissolved hydrogen ions (H+) in a solution
What is an acid?
A material with a pH of less than 7
What is a base?
A material with a pH greater than 7
When is a chemical considered neutral?
When it has a pH equal to 7
What pH values are considered to be strong?
2.5 or less and 12.5 or greater
Strong pH values will react more aggressively with…
Metallic substances
What are toxic products of combustion?
The hazardous chemical compounds released when a material decomposes under heat.
What does combustion generate?
Chemical by-products
What are some notable substances found in most fire smoke?
- Soot
- Carbon monoxide
- Carbon dioxide
- Water vapor
- Formaldehyde
- Cyanide compounds
- Oxides of nitrogen
The oxides of nitrogen causes a pulmonary edema, which is….
Fluid build of in the lungs
What is radiation?
Energy transmitted through space in the form of electromagnetic waves or energetic particles
The health hazards that radiation causes are dependent on what 2 factors?
- Amount of radiation your body absorbs
2. The exposure time
What is an alpha particle?
A type of radiation that quickly loses energy and can not travel far, 1 or 2 inches. Can’t pass through fabric.
What is a beta particle?
Type of radiation that can travel farther than alpha, 10 to 15 feet. Heavier materials can stop this, such as metal and glass.
What is gamma radiation?
Type of radiation that can travel significant distances. can penetrate most materials and go through the body
What is the most destructive type of radiation?
Gamma radiation
What is ionizing radiation?
Radiation with capability to cause changes in human cells, which may lead to mutation of the cell, and cancer.
What is a hazard?
A material capable of causing harm. Could be to health, safety, or the environment
What is an exposure?
Process by which something is subjected to or come into contact with a hazardous material.
What is contamination?
The process of transferring a hazardous material from its source to people, animals, environment or equipment, all of which may act as carriers.
What is decontamination?
The physical and/or chemical process of reducing and preventing the spread of contaminants from who/what’s involved at hazmat/wmd incidents
What is secondary comtamination(AKA cross contamination)?
When a person or object transfers the contaminant to another person or object by direct contact
True or False: PPE is worn to enable you to contact the contaminated product
False, this is a common misconception
What is the true purpose of PPE?
To protect you in the event that you cannot avoid contact with the contaminated product
What is the mnemonic device to remember the 7 types of damage that can be caused by WMD’s?
TRACEMP
What does TRACEMP stand for?
T - Thermal R - Radiological A - Asphyxiation C - Chemical E - Etiological M - Mechanical P - Psychogenic
What is the thermal part of TRACEMP?
Heat created from intentional explosions or fires, or cold generated by cryogenic liquids
What is the radiological part of TRACEMP?
Radioactive contamination from dirty bombs
What is the asphyxiation part of TRACEMP?
Oxygen deprivation caused by materials such as nitrogen; tissue asphyxiation from blood agents
What is the chemical part of TRACEMP?
Injury and death caused by intentional release of toxic industrial chemicals, nerve agents, vesicants, poisons or other chemicals
What is the etiological part of TRACEMP?
Illness and death resulting from biohazards such as anthrax, plague and smallpox; hazards posed by bloodborne pathogens
What is the mechanical part of TRACEMP?
Property damage and injury caused by explosions, debris, shrapnel, firearms, and slips trips and falls
What is the psychogenic part of TRACEMP?
Mental harm from being exposed to, contaminated by, and even being in close proximity to an incident
What is a nerve agent?
A toxic substance that attacks the central nervous system,
What is the main threat of a nerve agent?
Its ability to enter the body through the lungs or skin and then systematically affect the functions of the body
What does the mneumonic device, SLUDGEM, summarize?
SOme off the common signs and symptoms of exposure to nerve agents
What does SLUDGEM stand for?
S - Salivation L - Lacrimation (tearing) U - Urination D - Defecation G - Gastric disturbance E - Emesis (vomiting) M - Miosis (constriction of pupil)
What are blister agents (AKA vesicants)?
Agents that can cause blistering of the skin
What are some examples of blister agents?
Sulfur mustard and lewisite
What are blood agents?
Chemicals that interfere with the transfer of oxygen from the blood to the cells
What are some signs and symptoms of cyanide exposure (blood agent)?
Vomiting, dizziness, watery eyes, and deep and rapid breathing. In high concentrations: convulsions inability to breathe, loss of consciousness, and death
What are choking agents?
Chemical designed to inhibit breathing and typically intended to incapacitate rather than to kill
What are irritants (riot control agents)?
Substances, such as mace, that can be dispersed to briefly incapacitate a person
What are convulsants?
Chemicals capable of causing convulsions or seizures when absorbed by the body
(IMPORTANT FOR TEST) What are the 4 routes of entry?
- Inhalation
- Ingestion
- Absorption
- Injection
What is inhalation?
Brought into the body through the respiratory system
To fight inhalation, what is the most important piece of PPE a firefighter has?
A positive pressure, open circuit SCBA
Why are air puryifying respirators (APRs) not a viable option when oxygen content is low?
APRs do not provide oxygen
According to OSHA, when is an area considered oxygen deficient, requiring an SCBA?
When there is less than 19.5% oxygen in the area
What is the difference between infectious and contagious?
Infectious is capable of causing an illness, contagious is the capability to transmit a disease
Is anthrax infectious and/or contagious?
Anthrax is infectious but not contagious, because it can’t be passed to someone else.
What is absorption?
Permeating the skin
What is ingestion?
Brought into the body through the gastrointestinal tract
What is injection?
Brought into the body through open cuts and abrasions
What is a chronic health hazard?
An adverse health effect that occurs gradually over time after long term exposure
What is an acute health effects?
Health effects caused by short exposure periods to a harmful substance, produces observable conditions such as eye irritation, coughing, dizziness, and skin burns.
What is toxicity?
Measure of the degree to which something is toxic or poisonous
(CHIEF CONCEPTS) What is the most fundamental of all actions?
The ability to observe the scene and understand the problem
(CHIEF CONCEPTS) What is a critical step in comprehending the nature of a release?
Understanding why the vessel failed
(CHIEF CONCEPTS) What is the difference between a chemical change and a physical change?
A physical change is a change in state which a chemical change is a transformation at the molecular level
(CHIEF CONCEPTS) Nerve agents, blister agents, blood agents, choking agents, irritants, and convulsants are examples of what?
Hazardous materials that may be used as WMDs
(CHIEF CONCEPTS) Irritants, such as mace, can cause….
Immediate irritation of the skin, eyes and mucous membranes
(CHIEF CONCEPTS) What can APRs and SCBAs protect lungs from?
Select particulates such as smoke, dust and fumes
(CHIEF CONCEPTS) When may chronic health effects occur?
After years of exposure
