HazMat - Chemical and Physical Properties
Vapor pressure
-A measure of the ability of a material to change from a liquid state to a vapor or gas - The higher the VP the faster it will evaporate -Solids don't have VP, all Gases have VP -760 < its a Gas, 760 > its a Liquid Examples -Water (Evap at 18-25 mm/Hg) -Acetone ( Evap at 180 mm/Hg) Increase in surface area = increases rate of evaporation
Reactivity
-Ability to undergo a chemical reaction -Reactive materials can explode, combust, or spontaneously ignite when mixed with another substance
Molecular Weight (MW)
-Another way to determine vapor density -Compare gas to air -MW for air is 29 -MW more than 29 = SINK -MW less than 29 = RISE
Oxidizers
-Anything that gives off Oxygen -Oxygen feeds fire = very little smoke -Makes fire hotter & faster
Condensation
-Change from a gas to liquid
Polymerization (P)
-Chemical reaction where small molecules monomers combine to form larger ones called polymers -Can cause an explosion inside a space or vessel -Products likely to polymerize are indicated in a the ERG with a "P" following the guide number
Difference between Evaporation vs Boiling
-Evaporation is a SURFACE phenomenon -As surface area increases, evaporation rate increases -Boiling is a BULK process -Boiling point molecules anywhere in the liquid can be vaporized (Vapor Bubbles)
Cryogenic
-Have very low temperatures (below -130F) -May cause frostbite on contact Stored in Dewars
Solubility (Sol)
-How well a substance plays with water -Very important for Decontamination -Also called Miscible
Pyrophoric
-Means a chemical that will ignite spontaneously in air at a temperature of 130 degrees F (54.4 degrees C) or below
Ignition Temperature
-Minimum temperature to which a substance must be heated before it will spontaneously burn independently of the source of heat
Units used to measure concentration of gases and vapors in the air
-Percent % -Parts per million PPM -Parts per billion PPB
Specific Gravity (Sp.Gr)
-Physical property that tells us whether the substance will float or sink -Sp.Gr of water = 1.0 -SG greater than 1 = SINK in water -SG less than 1 = Float in water -Important when determining water vs foam ops
Inhibitors
-Substances added to monomers to prevent them from polymerizing
Melting point (MLT)
-Temp at which a solid becomes a liquid
Freezing Point (FRZ)
-Temperature at which a substance turns from a liquid to a solid -When a liquid is frozen to solid it stops giving off vapors
Water solubility
-The ability of a substance to form a solution with water -If a liquid is not miscible it will form a separate layer -Measured in %, 10% or more will come off with water Example Gasoline is not water soluble, and is therefore immiscible
Standard Temperature & Pressure
-The conditions under which the volume of a gas is usually measured -68 degrees F & 14.7 PSI
Flash point (Fl.P)
-The lowest temperature at which the vapor of a combustible liquid can be ignited in air
Atmospheric Pressure
-The pressure at any point in the Earth's atmosphere -1 ATM = 760 mmHg = 14.7 PSI @ sea level -With increasing altitude the atmospheric pressure decreases
Fire point
-The temp at which enough vapors are given off to support continuous burning -Usually 10-30 degrees higher than the flash point
Ambient Conditions
-The temperature of the surroundings at which the device is expected to operate -Usual or surrounding conditions of temperature, humidity, etc.
Concentration
-amount of acid or base compared to water -How much of one material there is in relation to another -One part per million= 1/1,000,000
Vapor density
-weight of a vapor compared to air -Property that tells whether a Gas or Vapor will rise or sink -VD of Air = 1.0 -VD Greater than 1.0 SINK -VD less than 1.0 RISE -In NIOSH VD = RGasD
Threshold limit value time weighted average (TLV-TWA)
ACGIH term for the maximum concentration averaged over 8 hours, to which healthy adults can be repeatedly exposed 8hrs/day, 40hrs/ week
BLEVE
Boiling, Liquid, Expanding, Vapor, Explosion -Sealed container of liquid is exposed to fire -Vapor is generated and increases internal pressure -Container fails in vapor area of tank
Corrosivity
CONCENTRATION OF HYDROGEN IONS IN THE MATERIAL BEING TESTED. ABILITY TO DESTROY MATERIAL
Irritant Detection Devices
Colormetric tubes, Ion-mobility spectrometry
Flammable Range
Difference between upper and lower flammable limits
Vesicant Detection Devices
Enzyme tickets (M256 Kit), colormetric tubes, M18A2 Chemical detection kit, ICAM, detection paper, infrared spectrometry, Ion-mobility spectrometry
Nerve agent Detection Devices
Enzyme tickets (M256 Kit), photo-ionization, colormetric tubes, M18A2 Chemical detection kit, ICAM, detection paper, infrared spectrometry, Ion-mobility spectrometry
Biological Agent Detection Devices
Hand Held Assays, Infrared Spectrometry (only the presence)
When temperature increases what happens to the vapor pressure?
It also increases
If a chemical doesn't have a RGasD value than what can you assume it is?
It's a Liquid
LEL / UEL
Lower Explosive Limit -Lower limit of flammability of a gas or vapor at ambient temperature Upper Explosive Limit -Highest concentration of a substance that will burn when an ignition source is present -Measured in % of gas vapor in air
Permissible exposure limits (PEL)
OSHA term for the maximum concentration averaged over 8 hours, to which 95% of healthy adults can be exposed 8hrs/day, 40hrs/ week
Alpha
Positively charged particle emitted by some radioactive materials and is most dangerous if ingested
Identifying unknown solid and liquid materials
Radioactivity, combustibility, oxygen availability, pH, Hydrogen sulfide, carbon monoxide, organic vapors (VOC)
Half-Life
Rate of decay of radioactive material
RGasD
Relative Gas Density
Catalyst
Speeds or slows a chemical reaction
pH
a solution's hydrogen ionization concentration as related to acidity or alkalinity
Radioactivity
ability of a material to emit radioactive energy
Expansion ratio
amount of gas produced by liquid at a given temp
Lethal Concentration (LC50)
amount of material in the air that causes death to fifty percent of test animals exposed to it by inhalation
Dose
amount of material the body is exposed over a specific time
Irritants
cause respiratory distress
Chemical Interactions
caused when two or more chemicals, or the chemical and the container are incompatible
Lethal Dose (LD50)
causes death to fifty percent of test animals exposed to it by any route other than inhalation
Volatility
determines how easily a liqiud flows, the property of changing readily from a solid or liquid to a vapor
Viscosity
determines how easily a liquid flows
Beta
emitted from radioactive materials and can cause damage to the skin tissue, and internal organs if ingested. Full protective clothing and SCBA can protect against this.
Gamma
emitted from radioactive materials causes skin burns, severely injure internal organs; PPE is inadequate in preventing this radiation from harming the body
Physical state
form of a material at ambient temperature (solid, liquid, gas)
Polar
having a pair of equal or opposite charges
Temperature of product
influences the hazards present and measures taken to control an incident involving that product
Sublimation
material that changes from solid to vapor without passing through liquid phase Examples -Moth balls -Dry Ice
Acid
material with a PH < 7
Caustic (Base)
material with a PH > 7
Air reactivity
materials that can ignite if exposed to air
Instability
materials that spontaneously decompose, polymerize, or self react
Threshold limit value short-term exposure limit (TLV-STEL)
maximum concentration averaged over 15 minute period, to which healthy adults can be safely exposed for up to 15 minutes continuously
Threshold limit value ceiling (TLV-C)
maximum concentration averaged to which healthy adults can be exposed without risk of injury
Immediately dangerous to life and health value (IDLH)
maximum level to which a healthy worker can be exposed for 30 minutes and escape without suffering irreversible health effects or impairment
parts per million/billion (ppm/ppb)
measures the degree of hazard and values used to establish exposure limits
Time, distance, and shielding
methods of protecting onself from radiation exposure
Solution
mixture where all ingredients are dissolved
Slurry
pourable mix of solids and liquids
Dose rate
radiation dose per unit of time
Three types of hydrocarbons
saturated, unsaturated, aromatic
Water reactivity
sensitivity of a material to water
Chemical reactivity
substance releases energy or undergoes change
Nerve agents
substances that interfere with the central nervous system
Vesicants
term for blister agents which are extremely toxic
Absorbed Dose
the amount of energy deposited per unit mass of absorbing material
Strength
the degree of ionization of an acid or base in water
Autoignition
the lowest temp at which a material must be raised before it will ignite
Boiling Point (BP)
the temperature at which a substance changes from a liquid to a gas -The temperature at which the vapor pressure of that substance is equal to 760 mm/Hg
Chemical Reaction
when elements and compounds make new substances