chemical and physical properties

Learning Objective 1: States of Matter

• Matter exists in three states:

  • Solid

  • Liquid

  • Gas

• The state of matter influences a material's behavior.

  • Solids: Potentially reactive, stay in place unless moved; small particles may suspend in air, causing entrapment.

  • Liquids: Indefinite shape, flow downhill, may sink or float in water, release vapors that behave like gases.

  • Gases: Indefinite shape, expand rapidly, may displace oxygen, travel quickly, may rise or sink in air.

• ERG establishes initial isolation distances based on matter state:

  • Solids: $75$ ft ($25$m)

  • Liquids: $150$ ft ($50$m)

  • Gases: $330$ ft ($100$m)

• Gases are potentially the most dangerous for responders:

  • May have an odor or be colorless, odorless, and/or tasteless.

  • May be toxic, corrosive, or flammable.

  • May be under high pressure.

  • May be extremely cold and/or have a large expansion ratio if liquefied.

• Incidents involving gases are often difficult to mitigate, requiring large perimeters.

• Gases may require monitoring and detection devices.

• Gases may present multiple hazards, such as inhalation hazards.

• Liquids are usually visible, making it easier to detect their presence and hazards.

• Responders may be able to predict the most likely paths that spilled liquids will follow.

• Liquids follow topography and can be contained.

• Liquids present a splash hazard.

• Vapors from liquids present additional hazards:

  • Contact hazards

  • Inhalation hazards

  • Flammable

  • Corrosive

  • Toxic

• Vapors from liquids behave like gases and may be flammable, corrosive, or toxic.

• Solids are the least mobile of the three states of matter.

• The particle size of solids may influence their behavior.

• Solids may have multiple hazards:

  • Inhalation or contact hazards

  • Small, combustible particles that, if ignited, may explode

  • Entrapment hazard

  • Flammable, reactive, radioactive, corrosive, toxic

Learning Objective 2: Physical Properties

• Physical properties do not involve a change in chemical identity.

• Materials can be characterized by physical properties:

  • Vapor pressure

  • Boiling point

  • Melting point/freezing point/sublimation

  • Vapor density

  • Solubility/miscibility

  • Specific gravity

  • Persistence

  • Appearance and odor

• Vapor pressure is the pressure produced by the vapors of a released liquid.

  • Materials with a vapor pressure over $760$ mmHg will be gases under normal conditions.

  • The higher the temperature of a substance, the higher its vapor pressure will be.

  • Atmospheric pressure is the baseline measurement for pressure.

  • The lower the boiling point, the higher its vapor pressure will be.

• A liquid's vapor pressure increases as the temperature rises.

• Vapor Pressure - Examples:

  • Chlorine Gas: $5168$ mmHg

  • Isopropyl Alcohol: $33$ mmHg

  • Ethyl Chloride: $1000$ mmHg

  • Water: $17$ mmHg

  • Ethylene Glycol: $.05$ mmHg

  • Sulfuric Acid: $.001$ mmHg

• Boiling point is the temperature at which a liquid changes to a gas at a given pressure (e.g., $212$°F ($100$°C) at Sea Level).

• Temperature strongly influences state of matter and behavior.

  • Temperature and Pressure are Directly Related

    • Temperature Up = Pressure Up

    • Temperature Down = Pressure Down

• A BLEVE can cause catastrophic container failure.

  • Liquid within a container is heated.

  • Material inside boils or vaporizes.

  • If increasing internal vapor pressure exceeds vessel's ability to relieve/retain excess pressure, the container can fail catastrophically.

  • As vapor is released, it expands rapidly and ignites.

• BLEVE: Boiling Liquid Expanding Vapor Explosion

• Melting point, freezing point, and sublimation affect hazards.

  • Dry ice sublimates from a solid into a gas without transitioning into a liquid.

• Vapor density affects the weight of gases (Air = $1.0$).

  • Value > $1$ are heavier than air and will sink

  • Value < $1$ are lighter than air and rise

  • Example: PROPANE: VAP DENSITY=$1.5$ Will stay close to the ground

  • Materials with vapor densities less than one will rise in air.

  • Materials with vapor densities greater than one will sink in air.

• Most gases have a vapor density greater than $1$.

  • Common gases with Vapor Density > $1$: Propane, Hydrogen sulfide, Ethane, Butane, Chlorine, Sulfur dioxide.

• Gases and vapors that are heavier than air may concentrate in low-lying areas.

• Gases LIGHTER THAN AIR MEDIC ANNA: HELIUM, HYDROGEN, HYDROGEN CYANIDE, HYDROGEN FLUORIDE, METHANE, ETHYLENE, DIBORANE, ILLUMINATING GASES, CARBON MONOXIDE, ACETYLENE, NEON, NITROGEN, AMMONIA

• Solubility is the degree to which a material dissolves in water.

  • Solubility information affects spill cleanup methods and symptom development.

• Hydrocarbons are non-water soluble and do not dissolve in water.

• Miscibility is the ability of two liquids to mix together.

  • Miscible: Liquids that mix or dissolve into each other.

  • Immiscible: Incapable of being mixed or blended with another substance.

• Because oil is immiscible, it will float on water and could ignite and burn.

• Materials with a specific gravity greater than one will sink in water.

• An important consideration for fire-suppression activities is that most flammable liquids will float on water.

• Viscosity is the measure of the thickness or flowability of a liquid at a given temperature.

  • Water has Low viscosity.

  • Molasses has High viscosity.

• The viscosity of materials will affect decontamination or collection.

  • Viscous materials:

    • Tend to be more persistent

    • May have a lower vapor pressure

• Persistent chemicals stick around in the environment before dispersing.

• Persistence is not often referenced on an SDS.

• The SDS typically contains a description of a material's appearance.

  • Change in appearance may indicate a change in the behavior of the material.

• Odorants may be added to some hazardous materials to make them easier to detect.

• The ability to smell or sense an odor is highly dependent on the individual.

  • Never use odors to determine safe or unsafe areas

  • Some highly toxic products may cause significant damage at a concentration below the odor threshold

  • Responders spending too much time exposed to some compounds may become desensitized to the smell of a chemical and may no longer be able to determine its presence

• Odour Threshold Concentration at which a material can be detected by smell, generally found in SDS

Chemical Properties

• Chemical properties describe behaviors and interactions that occur at a molecular level.

  • Flammability

  • Corrosivity

  • Reactivity

  • Radioactivity

• Most hazardous materials incidents involve flammable materials.

  • Flammable materials can damage life and property when they ignite, burn, or explode.

  • Use a hazard's flammability to help determine incident strategies and tactics.

• A flammable hazard depends on flash point, flammable range, and autoignition temperature.

• Flash point is the minimum temperature at which a liquid or volatile solid gives off sufficient vapors at its lower explosive limit (LEL) to form an ignitable mixture with air.

• A material's fire point is usually only a few degrees higher than its flash point.

  • Fire point is the temperature at which a liquid or volatile substance gives off enough vapors to support continuous burning.

• Autoignition temperature is the point at which a fuel spontaneously ignites.

  • Minimum temperature to which the fuel in air must be heated to initiate self-sustained combustion without initiation from an independent ignition source

  • Considerably higher than the flash and fire points

• The flammable range is the percentage of vapor concentration in the air that will burn or explode if ignited.

• A material must fall in the flammability range to burn.

• Within the upper and lower limits, the gas or vapor concentration will burn rapidly if ignited.

  • The upper explosive limit (UEL) or upper flammable limit (UFL) is the highest concentration that will produce a flash of fire when an ignition source is present.

  • The lower explosive limit (LEL) or lower flammable limit (LFL) is the lowest concentration that will produce a flash of fire when an ignition source is present.

• Atmospheres within the flammable range are particularly dangerous.

• Table 4.1 Flammable Ranges for Selected Materials:

  • Material, Lower Flammable Limit (LFL) (percent by volume), Upper Flammable Limit (UFL) (percent by volume)

  • Acetylene $2.5$, $100.0$

  • Carbon Monoxide $12.5$, $74.0$

  • Ethyl Alcohol $3.3$, $19.0$

  • Fuel Oil No. 1 $0.7$, $5.0$

  • Gasoline $1.4$, $7.6$

  • Methane $5.0$, $15.0$

  • Propane $2.1$, $9.5$

• Corrosives are materials that destroy living tissue and damage or destroy metal.

  • Commonly divided into acids and bases.

  • Measured or expressed in terms of pH.

• pH measures the acidity or alkalinity of a solution.

  • Concentration of Hydrogen lons Compared to Distilled Water

  • pH Scale Examples of Solutions at this pH

    • $0$ Strong Hydrofluoric Acid

    • $1$ Battery Acid

    • $2$ Vinegar

    • $3$ Orange Juice

    • $4$ Acid rain, Wine

    • $5$ Black Coffee

    • $6$ Milk

    • $7$ Distilled Water

    • $8$ Seawater

    • $9$ Baking Soda

    • $10$ Milk of Magnesia

    • $11$ Ammonia

    • $12$ Lime

    • $13$ Lye

    • $14$ Sodium Hydroxide

• An acid dissociates to yield hydrogen ions in water.

  • pH values of $0$ to $6.9$

  • May cause severe chemical burns to flesh and permanent eye damage.

  • Contact typically causes immediate pain.

  • Examples include hydrochloric acid, nitric acid, sulfuric acid.

• A base dissociates to yield hydroxide ions in water.

  • pH values of $7.1$ to $14$

  • Breaks down fatty skin tissues and can penetrate deeply into the body.

  • Examples include caustic soda, potassium hydroxide, and other alkaline materials commonly used in drain cleaners.

• Bases can cause severe eye and tissue damage.

  • Bases tend to adhere to the tissues in the eye and are difficult to remove.

  • Longer exposure means that bases often cause more eye damage than acids.

  • Contact with a base does not normally cause immediate pain.

    • A common sign of exposure to a base is a greasy or slick feeling of the skin caused by breakdown of fatty tissues (saponification).

• The chemical reactivity of a substance describes its relative ability to undergo a chemical reaction.

  • Reactive materials commonly react vigorously or violently with air, water, heat, light, each other, or other materials.

  • May result in pressure buildup, temperature increase, and/or formation of noxious, toxic, or corrosive by-products.

• Many reactions need an oxidizing agent, a reducing agent, and activation energy to get started (Reactivity Triangle).

• Activation energy is the energy needed to start a reaction.

Hazard Classes

• There are nine reactive hazard classes:

  • Highly flammable

  • Explosive

  • Polymerizable

  • Strong oxidizing agent

  • Strong reducing agent

  • Water-reactive

  • Air-reactive

  • Peroxidizable compound

  • Radioactive material

• The oxidizing agent in the reactivity triangle provides the oxygen necessary for the chemical reaction.

  • Strong oxidizers are materials that encourage a strong reaction (by readily accepting electrons) from reducing agents (fuels).

  • In general, the stronger the oxidizer, the stronger the reaction.

  • Many organic materials ignite spontaneously when they come into contact with a strong oxidizer.

• If spilled on asphalt, liquid oxygen could cause an explosion.

• The reducing agent acts as the fuel source for the reaction. Reducing + oxygen => Energy is released

  • Some reducing agents (fuels) are more volatile than others

• Polymerization is a chemical reaction that forms long chain molecules.

  • Simple molecules form long chain molecules.

  • Rate increased by catalyst.

  • Catalyst decreases activation energy needed.

  • Examples of catalysts include light, heat, water, acids, or other chemicals.

• Uncontrolled polymerization often results in a tremendous release of energy.

• Materials that may undergo violent polymerization if subjected to heat or contamination are designated with a P in the blue and yellow sections of the ERG

• Inhibitors are materials that are added to products to control an undesired reaction. Added to products that easily polymerize in order to control or prevent an undesired reaction.

  • Increase the needed activation energy.

  • May be exhausted over a period of time or when exposed to circumstances or unexpected contamination that causes them to be consumed more rapidly.

• Shipments of polymerizing materials may become unstable.

  • Time-sensitive inhibitors are added to liquid styrene before it is shipped.

• Reactive materials can be extremely destructive and dangerous.

  • With advances in modern technology, more reactive and unstable materials are being used for various processes, and you must be prepared to deal with them.

  • Keep people and equipment upwind, uphill, and back a safe distance or in protected locations until pertinent facts are established and definite plans can be formulated.

• Radiation comes in different forms, some more energetic than others.

  • Radiation Types in the Electromagnetic Spectrum:

    • Nonionizing: Radio Extremely Low Frequency, Microwave, Infrared, Visible Light

    • Ionizing: Ultraviolet, X-Ray, Gamma Rays

• There are four types of ionizing radiation that can be stopped by:

  • Alpha particles stopped by skin

  • Beta particles stopped by clothing

  • Gamma particles stopped by Lead

  • Neutron particles stopped by Concrete

• During radioactive decay, alpha particles are emitted from the nucleus of an atom.

• Alpha particles do not travel far in open air. Lose energy rapidly when travelling through matter.

  • Do not penetrate deeply.

  • Usually completely blocked by the outer, dead layer of the human skin.

  • Not a hazard outside the body.

  • Can be very harmful if ingested or inhaled.

• Beta particles travel farther and faster than alpha particles.

  • Fast-moving, positively charged protons or negatively charged electrons.

    Emitted from the atom's nucleus during radioactive decay

  • Human exposure from manufactured and natural sources such as tritium, carbon-$14$, and strontium-$90$

  • Most hazardous when inhaled or ingested

• Beta particles penetrate further than alpha particles, but cause less damage.

  • Travel appreciable distances in air.

  • Can be reduced or stopped by a layer of clothing, a thin sheet of metal, or thick Plexiglass.

  • Detection distances for beta particles vary based on the activity of the source.

  • Compared to alpha radiation, beta radiation will travel farther. Shielding beta emitters with dense metals can result in the release of X-rays.

• Gamma particles are high energy photons.

  • Often accompany the emission of alpha or beta particles from a nucleus

  • Have neither a charge nor a mass but are penetrating

  • Can easily pass completely through the human body or be absorbed by tissue

  • Constitutes a radiation hazard for the entire body

• Gamma exposure sources include both natural and industrial.

  • Gamma radiation levels vary depending on the isotope and activity.

  • Materials such as concrete, earth, and lead may be useful as a shield against radiation.

  • Standard fire fighting protective clothing provides no protection against gamma radiation.

• X-rays and gamma rays are high energy radiation called photons.

  • Hazards directly correlated to their activity

  • Machines such as those found in medical facilities and airports are almost exclusively the sole source of terrestrial X-ray radiation

  • Since machines can only produce X-rays when powered on, the chances of encountering X-rays at a hazardous materials incident are remote

• Radioactive materials could be used in a terrorist attack.

• Radiation exposure occurs when a person near a radiation source is exposed to energy from that source.

  • A person may receive a dose of radiation based upon the length of exposure, energy, and type of source.

  • Damage is often described in terms of dosage, indicating the amount of energy absorbed.

• Radioactive contamination occurs when radioactive material is deposited any place where it is not desired.

  • Exposure to radiation alone does not contaminate a person.

  • Contamination only occurs when the radioactive material remains on a person or the person's clothing after coming into contact with a contaminant.

  • A person can become contaminated externally, internally, or both.

• Radioactive contamination can spread. An unprotected person contaminated with radioactive material receives radiation exposure until the source of radiation (radioactive material) is removed.

  • Radiation detectors capable of detecting alpha and beta contamination can detect radioactive contamination.

• The effects of ionizing radiation occur at the cellular level.

  • Radiation may cause damage to any material by ionizing the atoms in that material.

  • When atoms are ionized, the chemical properties of those atoms are altered.

  • This can result in a change in the chemical behavior of the atoms and/or molecules in the cell.

  • A sufficiently high dose of radiation can damage many cells. May cause observable health effects, including genetic mutations and cancer.

• The presence of radiation placards at an incident should trigger radiation detection and monitoring plans.

• Use time, distance, and shielding to protect yourself from radiation hazards.

• Doubling the distance from a radiation source divides the dose by a factor of four (Inverse Square Law).

• Using time, distance, and shielding to limit exposure to radiation is sometimes referred to as the ALARA (As Low As Reasonably Achievable) method or principle.

• Limit your time to limit the dose! Maximize your distance to limit the dose! Use shielding to limit your dose!

• The degree to which a substance causes harm within the body is called its toxicity.

  • Local toxic effect: A chemical injury at the site of contact (typically the skin and mucous membranes of the eyes, nose, mouth, or respiratory tract).

  • Systemic effects: Toxic materials may be absorbed into the bloodstream and distributed to other parts of the body. Multiple systemic effects are possible.

• All personnel working at hazardous materials incidents must use appropriate personal protective equipment, including appropriate respiratory protection equipment.

• There are many toxic chemical hazard categories:

  • Asphyxiants

  • Irritants

  • Convulsants

  • Carcinogens

  • Allergens and Sensitizers

• Asphyxiants prevent access to sufficient volumes of oxygen.

• Irritants cause temporary, sometimes severe, inflammation.

• Convulsants cause convulsions and can kill the victim.

• Carcinogens are known, or suspected, to cause cancer.

  • Common Risk Factors (example: Firefighters Risks)

    • Brain Cancer $1.3x$

    • Skin Cancer $1.4x$

    • Myeloma $1.5x$

    • Melanoma $1.3x$

    • Non-Hodgkin's Lymphoma $1.5x$

    • Colon Cancer $1.2x$

    • Prostate Cancer $1.3x$

    • Testicular Cancer $2x$

• Individuals exposed to a material may experience effects after one or multiple exposures.

• Allergens cause allergic reactions.

• Sensitizers cause a substantial proportion of exposed people or animals to develop an allergic reaction after one or more exposures.

• Biological (etiological) hazards may cause severe, disabling disease or illness.

  • Biological toxins

  • Viruses

  • Rickettsias

  • Bacteria

• Viruses are the simplest types of microorganisms.

• Bacteria are microscopic, single-celled organisms.

• Rickettsias are specialized bacteria that live and multiply in arthropod carriers (such as ticks and fleas).

• Biological toxins are produced by living organisms (Ricin, a biological toxin, is made from castor beans).

• Many diseases are considered biological hazards.

  • Malaria

  • Typhoid

  • Tuberculosis

  • Influenza

  • Ebola

  • Hepatitis B

  • Measles

• Biological agents may be used as weapons in terrorist attacks or criminal activities.

  • Botulism

  • Smallpox

  • Anthrax

Learning Objective 4: Define the Hazard Classes

• There are nine transportation hazard classes:

  • Class 1 - Explosives

  • Class 2 - Gases

  • Class 3 - Flammable liquids (and combustible liquids in the U.S.)

  • Class 4 - Flammable solids, spontaneously combustible, and dangerous when wet

  • Class 5 - Oxidizers and organic peroxides

  • Class 6 - Poisons, poison inhalation hazards, and infectious substances

  • Class 7 - Radioactive materials

  • Class 8 - Corrosives

  • Class 9 - Miscellaneous hazardous materials

• Explosives are reactive and may release energy.

• Explosive placards list both a division number and a compatibility group letter

• Certain containers and storage areas are specifically designed for explosives.

• Rapidly released gases can create a blast-pressure wave (shock wave).

  • Travels outward from the center As the wave increases in distance, the strength decreases

  • Primary reason for injuries and damage

  • Positive and negative phase, both can cause damage

• The positive pressure wave can be extremely destructive.

• Additional damage can be done during the negative pressure phase.

• There are multiple effects of an explosion that can cause damage:

  • Fragmentation Effect Shock Front

  • Incendiary

• Shrapnel and fragmentation may be thrown over a wide area.

  • Small pieces of debris thrown from a container or structure that ruptures during an explosion from containment or restricted blast pressure

  • May cause personal injury and other types of damage to surrounding structures or objects

  • Can result in bruises, punctures, or even avulsions (part of the body being torn away) when they strike a person

• Explosions can cause a seismic effect.

  • When a blast occurs at or near ground level, the air blast creates a ground shock or crater

  • As the shock waves move across or underground, they form a seismic disturbance

  • The distance the shock wave travels depends on the type and size of the explosion and type of soil

• The incendiary thermal effect occurs when a fireball is formed during an explosion fireballs

  • Result from interactions among burning combustible gases or flammable vapors and ambient air at high temperatures

  • Present for a limited time after explosive event

• There are additional hazards unrelated to the explosion.

  • Chemical hazards will probably result from production of toxic gases and vapors

  • Explosives may self-contaminate as they age, which increases their sensitivity and instability

  • Explosives may have high sensitivity to shock and friction

• DOT divides Class $1$ into six divisions (Table 4.5 & 4.6).

  Explosives that have a mass explosion hazard. A mass explosion is one that affects almost the entire load instantaneously. Examples: Dynamite, mines, wetted mercury fulminate

  Explosives that have a projection hazard but not a mass explosion hazard. Examples: Detonation cord, rockets (with bursting charge), flares, fireworks

  Explosives that have a fire hazard and either a minor blast hazard or a minor projection hazard or both. Not a mass explosion hazard. Examples: Liquid-fueled rocket motors, smokeless powder, practice grenades, aerial flares

  Explosives that present a minor explosion hazard. The explosive effects are largely confined to the package and no projection of fragments of appreciable size or range is expected. An external fire must not cause virtually instantaneous explosion of almost the entire contents of the package. Examples: Signal cartridges, cap type primers, igniter fuses, fireworks

  Substances that have a mass explosion hazard but are so insensitive that there is little probability of initiation or of transition from burning to detonation under normal transportation conditions. Examples: Prilled ammonium nitrate fertilizer or fuel oil (ANFO) mixtures and blasting agents

  Extremely insensitive articles that do not have a mass explosive hazard. This division is comprised of articles that contain only extremely insensitive detonating substances and that demonstrate a negligible probability of accidental initiation or propagation. Examples: Wetted cellulose nitrate, low vulnerability military weapons

  Gases are materials that are in a gaseous state at normal temperatures and pressures.

  Gases are transported or stored in pressure containers or cryogenic containers.

  Gas division numbers are assigned according to the type of potential hazard. Potential Hazards of Gases: Toxicity, Corrosivity, Energy

  Gases have other hazards as well:

  -- Heat hazards Fires, particularly associated with Division $2.1$ and oxygen

• -- Asphyxiation hazards Leaking or released gases displacing oxygen in a confined space

  -- Cold hazards Exposure to Division $2.2$ cryogens

  -- Mechanical hazards A BLEVE (boiling liquid expanding vapor explosion) for containers exposed to heat or flame; a ruptured cylinder rocketing after exposure to heat or flame

  -- Chemical hazards Toxic and/or corrosive gases and vapors

  There are multiple Class $2$ divisions and placards.

  Flammable Gas- Consists of any material that is a gas at $68$°F ($20$°C) or less at normal atmospheric pressure or a material that has a boiling point of $68$°F ($20$°C) or less at normal atmospheric pressure and that

  (1) Is ignitable at normal atmospheric pressure when in a mixture of $13$ percent or less by volume with air, or

  (2) Has a flammable range at normal atmospheric pressure with air of at least $12$ percent, regardless of the lower limit. Examples compressed hydrogen, isobutene, methane, and propane

  Nonflammable, Nonpoisonous Gas - Nonflammable, nonpoisonous compressed gas, including compressed gas, liquefied gas, pressurized cryogenic gas, and compressed gas in solution, asphyxiant gas and oxidizing gas; means any material (or mixture) which exerts in the packaging an absolute pressure of $40.6$ psi ($280$ kPa) or greater at $68$°F ($20$°C) and does not meet the definition of Divisions $2.1$ or $2.3$. Examples carbon dioxide, helium, compressed neon, refrigerated liquid nitrogen, cryogenic argon

  Gas Poisonous by Inhalation - Material that is a gas at $68$°F ($20$°C) or less and a pressure of $14.7$ psi ($101.3$ kPa) (a material that has a boiling point of $68$°F [$20$°C] or less at $14.7$ psi [$101.3$ kPa]), and that is known to be so toxic to humans as to pose a hazard to health during transportation; or (in the absence of adequate data on human toxicity) is presumed to be toxic to humans because of specific test criteria on laboratory animals.

  Division $2.3$ has ERG-designated hazard zones associated with it, determined by the concentration of gas in the air:

  Hazard Zone A LC50 less than or equal to $200$ ppm

  Hazard Zone B - LC50 greater than $200$ ppm and less than or equal to $1,000$ ppm

  Hazard Zone C-LC50 greater than $1,000$ ppm and less than or equal to $3,000$ ppm

  Hazard Zone D- LC50 greater than $3,000$ ppm and less than or equal to $5,000$ ppm

  Examples cyanide, diphosgene, germane, phosphine, selenium hexafluoride, and hydrocyanic acid

  Oxygen Placard - Oxygen is not a separate division under Class $2$, but first responders may see this oxygen placard on containers with $1,001$ lbs ($454$ kg) or more gross weight of either compressed gas or refrigerated liquid.

  Most hazmat incidents involve Class $3$ materials.

  All flammable and combustible liquids exhibit varying degrees of toxicity

  Some flammable liquids are also corrosive

  Flammable and combustible liquids ignite and burn with relative ease.

  In most conditions, Class $3$ materials will give off flammable vapors that behave much like gases..

  The primary hazards of flammable and combustible liquids are energy, corrosivity, and toxicity.

  Thermal hazards (heat) - Fires and vapor explosions

  Asphyxiation - Heavier-than-air vapors displacing oxygen in low-lying and/or confined spaces

  Chemical hazards - Toxic and/or corrosive gases and vapors; these may be produced by fires

  Mechanical hazards A BLEVE, for containers exposed to heat or flame; caused by a vapor explosion

  Vapors - Can mix with air and travel great distances to an ignition source

  Environmental hazards (pollution) Caused by runoff from fire control

  Flammability is the primary hazard for Class $3$ materials.

  Class Materials are divided into three divisions.

  Water Reactive Material Reaction:

  Flammable Gases + Water Spray, Heat, Toxic Gases, Corrosive Solutions

  Incidents involving Class $4$ materials can be difficult to manage.

  Even more experienced responders may not fully understand the hazards

  Typical response may make the situation worse

  There are thermal hazards to Class $4$ materials.

  Fires that may start or reignite spontaneously or upon contact with air or water

  Molten substances

  Fires and vapor explosions

  Other hazards of these materials include chemical energy, mechanical energy, corrosivity, and toxicity.

  Chemical hazards from irritating, corrosive, and/or highly toxic gases and vapors produced by fire or decomposition

  Severe chemical burns

  Mechanical effects from a BLEVE or other unexpected, violent chemical reactions and explosions.

  Chemical hazards from production of various chemicals

  Environmental hazards (pollution) caused by runoff from fire control

  There are multiple Class $4$ divisions and placards.

  Class Oxidizers and Organic Peroxides, is divided into two divisions

  Oxidizers vigorously support combustion, may be explosive, and, may burn continuously.

  Organic peroxides are oxidizers that are prone to reactivity.

  If organic peroxides reach the self-accelerating decomposition temperature (SADT)

  They undergo a chemical change and may violently release from their packaging

  Immediately evacuate the area if the SADT is reached. If decomposition occurs, observe it from a safe distance and take only those measures necessary to preserve life and nearby property.

  The primary hazards of Class materials are thermal, mechanical, and chemical.

  Thermal hazards (heat) from fires that may explode or burn hot and fast or materials'/substances' sensitivity to heat, friction, shock, and contamination

  Explosive reactions to contact with hydrocarbons (fuels)

  Mechanical hazards such as violent reactions and explosions as well as sensitivity to heat, friction, shock, and/or contamination

  Chemical hazards from toxic gases, vapors, dust, or from products of combustion resulting in burns

  Thermal hazards from ignition of combustibles

  Asphyxiation hazards from accumulation of toxic fumes and dusts in confined spaces

  There are multiple Class divisions and placards.

  Class includes Poisons, Poison Inhalation Hazards, and Infectious Substances.

  Avoid contact with poisonous materials as they are toxic to humans.

  Inhalation hazards are toxic vapors that can be lethal if inhaled.

  Infectious substances and biohazards have the potential to cause disease in humans or animals.

  Infectious materials are typically shipped in small containers, so there is no placard for them, only a label

  A biohazard label is used for large and small quantities of regulated medical waste

  Class materials also have secondary hazards.

  Toxic hazards

  Thermal hazards (heat) from flammability and fires

  Chemical hazards from toxic and/or corrosive products of combustion

  Thermal hazards (heat) from substances transported in molten form

  Do not inhale or come into contact with the secondary hazards of Class materials.

  There are multiple Class divisions and placards.

  Class has two unique placards.

  Class encompasses radioactive materials.

  Radioactive materials cannot be detected with the senses.

  Class placards and labels can indicate that radioactive materials are present

  Without specialized monitoring and detection equipment, it is not possible to determine if a container is actually emitting radiation

  It is impossible to tell if radiation is involved in an incident, such as a terrorist attack, where no placards or labels are evident

  Small packages of radioactive materials must be labeled on two opposite sides.

  Unique trefoil symbol for radiation

  Class labels must provide the isotope name, activity level, transport index, and radioactive level

  Common industrial and medical isotope names might be seen on Class labels.

• Common Isotopes:

  Industrial Cs-$137$, Co-$60$, Ir-$192$, Am-$241$

  Medical: Tl-$201$, Tc-$99$m, I-$131$, I-$125$, Pd-$103$, Ru-$106$

  Table provides Class placards, definitions, and examples.

  Class Corrosives, are either a liquid or solid that can damage metal and skin.

  Corrosives can be toxic, flammable, reactive, and/or explosive and some fare oxidizers…

  The primary hazards of Class materials are chemical, toxic, thermal and mechanical.

  Chemical hazards such as chemical burns

  Toxic hazards due to exposure via all routes of entry into a body

  Thermal hazards (heat), including fire, caused by chemical reactions generating heat

  Mechanical hazards caused by BLEVES and violent chemical