4 Chemical properties and hazmat behavior Flashcards
Gas
Fluid that has no independent shape or volume
Gasses tend to expand indefinitely
Liquid
No independent shape but does have volume, flow with gravity
Solid
Specific shape and volume order its own form
Gasses expand when release, on loving large areas, are difficult to contain and will move
According to air flow and prevailing winds
Dust
Solid particle formed or generated from solid material by mechanical means
Fume
Suspension of particles that form when material from volatile or vapors state solid condenses in cool air.
Mist
Finely divided liquid suspended in atmosphere
Aerosol
Mist form of minute particles of liquid, respirable
Fiber
Solid particle that’s much longer than wide
Vapor
Gaseous form of substance that is solid or liquid at room temp and pressure
Flash point
Minimum temp at which liquid gives enough vapor to form ignitable mixture with air near liquid surface. Will flash but not continue to burn
Fire point
Point at which enough vapors are given off to support continuous combustion. Usually slightly higher than flash point
Flash point of gasoline
-45F
Fire point of gasoline
-40 to -35F
Boiling point of gasoline
100-104F
Ignition temp of gasoline
536F
Flammable gasses have no flash point because
They are already in gaseous/vapor state
Epa and dot flammable liquid temp
Dot 141F or less
Eva 140 f or less
OSHA and nfpa flammable temp
Less than 100f
Dot combustible liquid temp
141-200f
Nfpa and OSHA combustible temp
100F or greater
Auto ignition temp
Minimum temp to support self sustained combustion without ignition source
Spontaneous ignition temp
Nfpa denies auto ignition and ignition temp as
Autoignition- temp with spontaneously ignite
Ignition temp- temp that initiate self sustained combustion independent of heating element.
CO binds to hemoglobin how many times more than 02
200 times
Hydrogen cyanide. HCN
Colorless toxic gas, bitter almonds, produced from combustion of nitrogen bearing substances
Flammable range of acetylene
2.5-100
Flammable range of CO
12.5-74.0
Ethyl aclohol flammable range
3.3-19
Fuel oil no1 flammable range
0.7-5
Gasoline flammable range
1.4-7.6
Methane flammable range (natural gas)
5-15
Propane flammable range
2.1-9.5
Vapor pressure
Measure of substances tendency to evaporate.
Pressure produced or exerted by vapors released from liquid.
As temp increases so do vapors
The higher the temp of a substance what will the vapor pressure be
Higher
The lower the boiling point of a substance the _______ the vapor pressure will be
Higher
Boiling point
Temp at which vapor pressure equals or exceeds atmospheric pressure. Rate of Evan exceeds rate of condensing.
More liquid turn the gas than turns back into liquid.
Flames impinging the vapor space of a tank can cause
Bleve faster. Liquid isn’t absorbing heat
Melting point
Temp a Solid turns to liquid at normal atmospheric pressure
Freezing point
Temp liquid becomes solid at normal atmospheric pressure.
Sublime
Changing directly into gas from solid with no liquid stage possible. Ex, co2 at atmospheric pressure is either solid or gas
Vapor density
Weight of given volume of pure vapor or gas compared to equal dry air. Less than 1 is lighter than air
More than 1 is heavier than air
Vapor density Less than 1
ammonia acetylene Helium, hydrogen, HCN, hydrogen fluoride, methane, neon, nitrogen,
Vapor density greater than 1
butane chlorine, ethane hydrogen sulfide Propane sulfur dioxide
Polar solvents _______ with water
Mix with water.
Water soluble irritants when inhaled cause symptoms
Soon
Partially water soluble chicks cause respiratory symptoms
Later, delayed, 12-24 hrs
penetrate desperate on respiratory system.
Miscibility
Two or more gas or liquids capability to mix together.
Immiscible
Two or more materials that do not readily dissolve or mix with one another
Specific gravity
Weight of substance in relation to equal volume of water at given temp.
Less than 1 lighter than water
Greater than 1 heavier than water
Persistence
Time a chem agent remains effective without dispersing
Time chem remains in environment without breaking down
Time chem agent remains liquid, typically more than 24 hrs
Reactivity
Substance ability to chem react with another material.
Reactivity triangle components
Oxidizing agent (02, peroxides, alkyl nitrates) Activation agent (heat, light, shock, radiation.) Reducing agent (fuel)
Strong oxidizer
Material encourages strong oxidation reaction, by readily accepting electrons, form a reducing agent (fuel)
If liquid Cryo O2 is spilled on asphalt, if stepped on the roadway could
Explode from oxidation rxn
Wood is less prone to undergo ______ as a highly flammable liquid like MEK
Rapid oxidation (won’t burn as easily)
The loss of electrons from a reducing agent to an oxidizer causes
Energy to be released, stronger the oxidation, stronger energy release
Polymerization
Chem rxn where catalyst causes simple molecules to combine, forming long chains, releases energy.
Substances that undergo violent polymerization if subjected to hear or contamination are marked with what in the blue and yellow sections of erg
Designated with a P
Inhibitors
Material added to control or prevent polymerization. Aka stabilizer
Inhibitors may be time sensitive, meaning
The become less effective over time
Overwhelmed by reaction trigger like heat
Exhausted over time by contamination
General hazardous material behavior model
General emergency behavior model GEBMO
Ludwig benner
Hazmats are things that can escape their containers and hurt or harm the things they touch.
Three states of matter
Gas
Liquid
Solid
GEBMO helps first responders
Predict course of incident, limit effects of hazmat
Defensive mode action
Sequence of events in hazmat incident
Stress Breach Release Dispersion/engulf Exposure/contact Harm
According to dot, what percentage is stress responsible for hazmat incident
1/4th
Stress
Stimulus causing strain,
Tension compression
Pressure, force applied at right angles
Deformity- torque or twisting
When evaluating container stress, consider
Type of container, type and amount of stress, duration of stress
Thermal stress
Excessive heat or cold causes excessive expansion and contraction, weakening, loss of temper
Chemical stress
Uncontrolled reactions of contents in container or the container itself, -sudden or long term deterioration of container
Mechanical stress
Physical application of energy causing damage or weakening, structural deformity
When a container is stressed beyond limits of recovery or its design it
Opens or breaches and releases
General loss of integrity, like glass bottle shattering, tank exploding
Brittle material
Disintegration breach
Crack develops and grows ralidly,
Associated with drums tanks or cylinders
Bleve
Runaway cracking breach
Attachments (closures) open or break
Breach
Valves, pressure reliefs break off or fail
Puncture breach
Mechanical action
Split or tear breach
Welded seam fails, bag seam fails
When a container fails, three things may be released
Product. Energy. Container (while or in pieces)
Releases are classified based on their speed
Detonation
Violent rupture
Rapid relief
Spill leak
Instant and explosive release of cored chem energy and hazmat
High explosive
Hundredths of seconds
Detonation release
Immediate release of chemor mech energy caused by runaway cracks. One second or less, Bleve
Violent rupture release
Fast release of pressurized hazmat through properly operating safety devices or damaged pipes or valves
Seconds or minutes.
Rapid relief
Release
Release under atmospheric head pressure through holes or other openings
Minutes or days.
Spill leak release
Dispersion of a material is sometimes referred to as
Engulf
Dispersion depends on
Type of release and physical chem properties of material
Dispersion is done according to five factors
Physical chem properties Prevailing weather conditions Local topography Duration of release Control efforts.
Semi circular or dome shaped release, airborne, partially in contact with ground or water. Generally from rapid release- detonation, deflagration, violent rupture
Hemispheric release
Ball shaped airborne. Collectively risen above ground. Gas vapor or dust/ aerosol
Cloud dispersion
Irregular shaped airborne, wind and topography influence spread
Gas and vapor
Plume dispersion
Triangular shaped pattern with point of source at breach and wide base downrange.
Cone dispersion
Surface following pattern of liquid. Affected by gravity and topography. Downslope
Stream dispersion
Three dimensional with depth slow liquid.
Pool dispersion
Irregular or indiscriminate depost of hazmat
Carried by persons
Irregular dispersal
Types of exposures to consider
People
Property
Environment
Contacts or impingement a are associated with the following time frames.
Immediate
Short term
Medium term
Long term
Immediate contact
Milliseconds, seconds,
Explosions, detonations
Short term contacts
Minutes, hours,
Gas or vapor cloud
Medium term contacts
Days weeks months
Lingering pesticide
Long term contacts
Years, generations
Radioactive sources
Harm
Injury or damage caused by hazmat exposure
