Transcript Slide 1

Properties and Hazards
• Introduction
– Hazardous materials may be
• Elements
• Compounds
• Mixtures
– Gaseous
– Liquid
– Solids
Properties and Hazards
• Introduction
– They may present a direct threat to health
• Poison
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Carcinogens
Toxic or highly toxic
Irritants
Corrosives
Sensitizers
Properties and Hazards
• Introduction
– They may be considered dangerous because
of their physical hazards
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Flammable
Compressed gases
Explosives
Organic peroxides
Oxidizers
Pyrophoric chemicals
Cryogenic materials
Radioactive materials
Water-reactive materials
Properties and Hazards
• Introduction
– The severity of hazards these materials
present range from
• Insignificant
• Catastrophic
– Depends on material and quantity involved
Properties and Hazards
• Introduction
– Exposures to hazardous materials
• Acute
– Single occurrence
• Chronic
– Long-term
– Reoccurring
Properties and Hazards
• Introduction
– Health effects from exposure
• Acute
– Short-term effects
– Appear within hours or days
» Vomiting
» Diarrhea
• Chronic
– May take years to appear
» Cancer
Properties and Hazards
• Hazardous Materials Properties
– Awareness level
• Need to understand
– Basic hazards associated with different classes of
hazardous materials
» Flammables
» Corrosives
» Reactives
– Operations level
• Need to know how hazardous materials
behave
• Signs and symptoms of an exposure
Properties and Hazards
• Hazardous Materials Properties
– Matter
• Substances that make up everything in the world
– Gas
» Fluid that has neither independent shape nor
volume
» Tend to expand indefinitely
– Liquid
» Fluid that has no independent shape but does
have a specific volume
» Flow in accordance with the laws of gravity
– Solid
» Substance that has both a specific shape and
volume (without a container)
Properties and Hazards
• Hazardous Materials Properties
– Flammability
• Majority of hazardous materials incidents involve
materials that are flammable
– Burn
– Explode
• Flammable hazards depend on
– Flash point
– Autoignition temperature
– Explosive or combustible range
Properties and Hazards
• Hazardous Materials Properties
– Flash Point
• Minimum temperature at which a liquid or
volatile solid gives off sufficient vapors to form an
ignitable mixture with air near its surface
– Vapors will flash
– Will NOT continue to burn
• DO NOT confuse with Fire Point
Properties and Hazards
• Hazardous Materials Properties
– Fire Point
• Temperature at which enough vapors are given off
to support continuous burning
– Temperature is usually only slightly higher than the
flash point
• Liquids and solids themselves do not burn
– Vapors they produce burn
» As temperature increases, more vapors are
produced
• Flammable gases have no flash point
Properties and Hazards
• Hazardous Materials Properties
– Autoignition Temperature/Autoignition Point
• Minimum temperature to which the fuel in air
must be heated to initiate self-sustained
combustion
– No independent ignition source
– Spontaneously ignites
– Considerably higher than the flash and fire points
• Ignition temperature is often used
synonymously
Properties and Hazards
• Hazardous Materials Properties
– Flammable, Explosive or Combustible Range
• Percentage of the gas or vapor concentration in
air that will burn or explode if ignited
Properties and Hazards
• Hazardous Materials Properties
– Flammable, Explosive or Combustible Range
• Lower explosive limit / lower flammable limit
– LEL / LFL
» Lowest concentration of a vapor/gas that will
produce a flash of fire
» Concentrations lower than the LEL
• Mixture is too lean to burn
Properties and Hazards
• Hazardous Materials Properties
– Flammable, Explosive or Combustible Range
• Upper explosive limit / upper flammable limit
– UEL / UFL
» Highest concentration of a vapor / gas that will
produce a flash of fire
» Concentrations higher than the UEL
• Mixture is too rich to burn
Properties and Hazards
• Hazardous Materials Properties
– Vapor Pressure
• Pressure exerted by a saturated vapor above its
own liquid in a closed container
– Pressure produced or exerted by the vapors released by
a liquid
» Can be expressed in terms of
• Pounds Per Square Inch (PSI)
• Kilopascals (kPa)
• Bars
• Millmeters of mercury (mmHg)
• Usually found on MSDS
• Atmospheres (atm)
Properties and Hazards
• Hazardous Materials Properties
– Vapor Pressure
• The higher the temperature of a substance, the
higher the vapor pressure will be
– Higher temperature provide more energy to a liquid
» Allows liquid to escape into a gas form
– The lower the boiling point of a substance, the higher
its vapor pressure will be
– Used as a general gauge to tell how fast a product
will evaporate under normal circumstances
Properties and Hazards
• Hazardous Materials Properties
– Boiling Point
• The temperature at which the vapor pressure of a
liquid is equal to or greater than atmospheric
pressure
– The temperature at which a liquid changes to a gas
– 760 mmHg = 14.7 psi or 1 atmosphere
Properties and Hazards
• Hazardous Materials Properties
– Boiling Liquid Expanding Vapor Explosion
• BLEVE
– Also called Violent Rupture
• Can occur when a liquid within a container is
heated
– Causes material inside to boil / vaporize
– Increases vapor pressure
– Exceeds the vessel’s ability to relieve the excess
pressure
» Most commonly occur when flames contact
a tank shell above the liquid level
Properties and Hazards
• Hazardous Materials Properties
– Melting Point
• Temperature at which a solid substance changes to a
liquid state
– Freezing Point
• Temperature at which a liquid becomes a solid
– Sublimation
• Substances changes from a solid directly
Into a gas
– Carbon dioxide (dry ice)
– Mothballs
Properties and Hazards
• Hazardous Materials Properties
– Vapor Density
• Weight of a given volume of pure gas
• Gas compared to the weight of an equal volume
of dry air
– Air has a value of 1
» Vapor density <1
• Vapor is lighter than air
» Vapor density >1
• Vapor is heavier than air
– All vapors / gases will mix with air
– Spread can not be predicted exactly from vapor
density
Properties and Hazards
• Hazardous Materials Properties
– Solubility
• Term expressing the percentage of a material (by
weight) that will dissolve in water at ambient
temperature
– Used for spill clean up methods
– Extinguishing agents
» Non-water soluble
• Liquids remain separate from water
» Polar solvent
• Liquids mix easily with water
Properties and Hazards
• Hazardous Materials Properties
– Solubility
• Health effects
– Water-soluble agents
» Cause early upper respiratory tract irritation
– Partially water-soluble agents
» Penetrate into the lower respiratory system
» Delayed symptoms
• 12-24 hours
» Causes breathing difficulties
• Pulmonary edema
• Coughing up blood
Properties and Hazards
• Hazardous Materials Properties
– Miscibility / Immiscibility
• The degree or readiness to which two or more
gases or liquids are able to mix with or dissolve
into each other
– Miscible
» Two liquids that dissolve into each other in any
proportion
– Immiscible
» Two materials that do not readily dissolve into
each other
Properties and Hazards
• Hazardous Materials Properties
– Specific Gravity
• Ratio of the density of a material to the density of
some standard material
– Heaviness of a material
– Water has a value of 1
» Specific gravity <1
• Liquid is lighter than water and will float
» Specific gravity >1
• Liquid is heavier than water and will sink
Properties and Hazards
• Hazardous Materials Properties
– Reactivity
• Relative ability to undergo a chemical reaction
with another material
– The fire tetrahedron
» Reactive triangle
• Fuel (Reducing Agent)
• Heat
• Oxygen (Oxidizer)
– Activation energy
» Required energy to get them started
• Starting a fire with a match
Properties and Hazards
• Hazardous Materials Properties
– Reactivity
• Examples
– Light-sensitive
– Heat-sensitive
– Shock-sensitive
• Polymerization
– Often results in a tremendous release of energy
» Designated with a “P” in the ERG
– Inhibitors are added in order to control or
prevent an undesired reaction
Properties and Hazards
• Hazardous Materials Hazards
– Health hazards
• Directly effect an individual’s health
– Poisons
– Corrosives
– Physical hazards
• Present a threat because of the material’s physical
properties
– Temperature
– Radioactivity
Properties and Hazards
• Hazardous Materials Hazards
– U.S. National Fire Academy (NFA)
• Uses a simple classification system
– TRACEMP
»T
»R
»A
»C
»E
»M
»P
Thermal
Radiological
Asphyxiation
Chemical
Etiological
Mechanical
Psychological
Properties and Hazards
• Hazardous Materials Hazards
– U.S. National Fire Academy (NFA)
• Uses a simple classification system
– TRACEMP
»T
Thermal
• Thermal harm is the result of exposure to
extremes of heat and cold
»R
Radiological
• Refers to nuclear radiation
• Alpha
• Beta
• Gamma
Properties and Hazards
• Hazardous Materials Hazards
– U.S. National Fire Academy (NFA)
• Uses a simple classification system
– TRACEMP
»A
Asphyxiation
• Interfere with oxygen flow during normal
breathing
• Simple asphyxiants
• Inert gases that displace or dilute
oxygen
• Chemical asphyxiants
• Blood poisons
Properties and Hazards
• Hazardous Materials Hazards
– U.S. National Fire Academy (NFA)
• Uses a simple classification system
– TRACEMP
»C
Chemical
• Toxic
• Harm depends on concentration and
length of exposure
• Corrosive
• Harm causes visible destruction
Properties and Hazards
• Hazardous Materials Hazards
– U.S. National Fire Academy (NFA)
• Uses a simple classification system
– TRACEMP
»E
Etiological
• Harm involves exposure to a living
microorganism
»M
Mechanical
• Causes trauma
• Shrapnel during an explosion
»P
Psychological
• Causes strong emotional reaction
Properties and Hazards
• Hazardous Materials Hazards
– Cryogenics
• Refrigerated liquefied gas
• Gases that turn into a liquid at or below -130o F
• Vaporize rapidly when released from container
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Liquid oxygen (LOX)
Liquefied natural gas (LNG)
Nitrogen
Helium
Hydrogen
Argon
Properties and Hazards
• Hazardous Materials Hazards
– Radiological
• Nonionizing radiation
– Has enough energy to move atoms around but not
change them chemically
» Radio waves
» Infrared radiation
» Microwaves
• Ionizing radiation
– The most energetic form of radiation
Properties and Hazards
• Hazardous Materials Hazards
– Radiological
• Ionizing radiation
– Has sufficient energy to remove electrons from atoms
» Disrupts chemical bonds
» Called “Ionization”
– Causes damage to the human body
Properties and Hazards
• Hazardous Materials Hazards
– Radiological
• Alpha Particles
– Lose energy rapidly in matter
– Do not penetrate very far
– Blocked by paper
• Beta Particles
– Fast moving
– Blocked by aluminum
Properties and Hazards
• Hazardous Materials Hazards
– Radiological
• Gamma Rays
– Similar to X-rays
– Completely pass through the human body
» Radiation hazard
– Stopped by a few inches of lead or several feet of
concrete
• X-rays
– Lower energy then gamma rays
– Stopped by a few inches of lead or several feet of
concrete
Properties and Hazards
• Hazardous Materials Hazards
– Radiological
• Neutrons
– Ultrahigh energy particles
– Highly penetrating
Properties and Hazards
• Hazardous Materials Hazards
– Radiological
• Exposure pathways
– Inhalation
» Breathe radioactive materials into the lungs
» Can remain in the lungs for a long time
– Ingestion
» Swallowing radioactive materials
» Expose entire digestive system
– Direct Exposure
» Skin contact
Properties and Hazards
• Hazardous Materials Hazards
– Radiological
• Protection Strategies
– Time
» Limit exposure time to radiation source
– Distance
» Increase distance from source
• Doubling distance reduces the exposure by a
factor of four
– Shielding
» Lead
» Concrete
Properties and Hazards
• Hazardous Materials Hazards
– Toxic Materials
• Nephrotoxic agents
– Affect the kidneys
• Hematotoxic agents
– Affect the blood
• Neurotoxic agents
– Affect the nervous system
• Hepatotoxic agents
– Affect the liver
Properties and Hazards
• Hazardous Materials Hazards
– Toxic Materials
• Lethal dose (LD)
– The minimum amount of a solid or liquid that will cause
death
• Median lethal dose (LD50)
– Single dose of a substance that can be expected to cause
death in 50% of animals
» Administered orally
» The other half isn’t completely well
• They just didn’t die
• Lethal dose low (LDLO or LDL)
– Lowest administered dose of a material capable of
killing a specific test species
Properties and Hazards
• Hazardous Materials Hazards
– Toxic Materials
• Lethal concentration (LC)
– Minimum concentration of an inhaled substance in the
gaseous state that will be fatal
» Usually within 1-4 hours
» May be expressed in LC50
• Lethal concentration low (LCLO or LCL)
– Lowest concentration of a gas or vapor capable of
killing a specified species over time
Properties and Hazards
• Hazardous Materials Hazards
– Toxic Materials
• Immediately Dangerous to Life or Health (IDLH)
– An atmospheric concentration of a substance that
poses an immediate threat to life
• Permissible Exposure Limit (PEL)
– Maximum concentration to which the majority of
healthy adults can be exposed over a 40-hour
workweek
» Time-Weighted Average (TWA)
• 8-hour period
Properties and Hazards
• Hazardous Materials Hazards
– Toxic Materials
• Permissible Exposure Limit Ceiling Limit (PEL) (C)
– The maximum concentration to which an employee
may be exposed at any time
» Instantaneous
• Short-term Exposure Limit (STEL)
– The maximum concentration allowed for a 15-minute
exposure
Properties and Hazards
• Hazardous Materials Hazards
– Toxic Materials
• Irritants
– Toxins that cause temporary but sometimes severe
inflammation to the eyes, skin or respiratory system
» Attack the mucous membranes of the body
• Convulsants
– Toxic materials that can cause convulsions
» Sensation of difficulty breathing
» Painful muscle spasms
• 3-30 minutes
Properties and Hazards
• Hazardous Materials Hazards
– Toxic Materials
• Corrosives
– Chemicals that destroy or burn living tissues and have
destructive effects
– With the exception of liquid and gas fuels
» Corrosives comprise the largest usage class in
industry
– Acids
» pH <6
– Bases (Alkalis)
» pH 8-14
Properties and Hazards
• Hazardous Materials Hazards
– Toxic Materials
• Carcinogens
– Cancer-causing agents
• Mutagens
– Substances or agents that are capable of altering the
genetic material in a living cell
Properties and Hazards
• Hazardous Materials Hazards
– Toxic Materials
• Teratogens
– Substances or agents that are capable of causing
developmental abnormalities in utero
» Malformation in the fetus of a pregnant female
• Sensitizers
– Chemicals that cause the development of allergic
reactions in people with repeated exposures
• Allergens
– Substances that cause allergic reactions
Properties and Hazards
Works Cited
N.F.P.A. 472 “Standard for Competence of responders to Hazardous
Materials/Weapons of Mass Destruction Incidents” 2008 Edition
N.F.P.A 1001 “Standard for Professional Firefighter Qualifications” 2008 Edition
N.F.P.A. 1561 “Standard on Emergency Services Incident Management System” 2008
Edition
O.S.H.A 29 CFR 1910.120 “Hazardous Waste Operations and Emergency Response”
U.S. DOT “Emergency Response Guidebook” 2008 Edition