Chapter 31 - HM Properties and Effects

A family member of a person hurt during a release of toxic gas has come to the cold zone of the scene. As the related subject is being moved out to an ambulance, the family member grabs the subject's watch. The family member has probably experienced what? (Page 1272)

A) Smoke inhalation

B) Secondary contamination

C) Confusion

D) A similar tragedy

B) Secondary contamination

Secondary contamination occurs when a person or object becomes contaminated through contact with someone or something exposed to a hazardous substance.

In this scenario, the injured person may have toxic material on their clothing, skin, or belongings. When the family member grabs the person's watch, they may transfer the contaminant to themselves.

A) Smoke inhalation: This involves breathing in smoke or combustion products. The scenario describes contact with a potentially contaminated object.

C) Confusion: The family member's behavior does not establish that they are confused; the main concern is potential contaminant transfer.

D) A similar tragedy: This is not a hazardous materials safety term and does not describe the risk presented.

Study Tip

Secondary contamination = contamination transferred to another person or object.

A flammable liquid will continue to produce significant vapor until it reaches what? (Page 1262)

A) Triple point

B) Freezing point

C) Boiling point

D) Flash point

B) Freezing point

The temperature at which a liquid becomes a solid. Freezing generally reduces vapor production because less liquid remains available to evaporate.

A) Triple point: The temperature and pressure at which a substance's solid, liquid, and gas phases coexist.

C) Boiling point: The temperature at which a liquid boils and vaporization occurs throughout the liquid.

D) Flash point: The lowest temperature at which a liquid produces enough vapor to ignite briefly when an ignition source is applied.

Study tip:

flash point = ignitable vapor

boiling point = boiling

freezing point = solidification.

A flash fire is possible for a flammable liquid: (Page 1262)

A) above the upper exposure limit if the liquid is a hydrocarbon.

B) between the upper exposure limit and the lower exposure limit.

C) only below the lower exposure limit.

D) above the upper exposure limit and below the lower exposure limit.

B) Between the upper exposure limit and the lower exposure limit

A flash fire can occur when a flammable vapor mixes with air at a concentration within its flammable range.

Lower Explosive Limit (LEL): The minimum vapor concentration in air that can ignite.

Upper Explosive Limit (UEL): The maximum vapor concentration in air that can ignite.

A flash fire is possible when the vapor concentration falls between these two limits and an ignition source is present.

A) Above the upper exposure limit if the liquid is a hydrocarbon: Above the UEL, the mixture is generally too rich in fuel to ignite because there is insufficient oxygen.

C) Only below the lower exposure limit: Below the LEL, the mixture is too lean, meaning there is insufficient fuel vapor to ignite.

D) Above the upper exposure limit and below the lower exposure limit: Both conditions describe concentrations outside the flammable range, not within it.

Study Tip

Too lean, no flame, too rich, no flame

Below the LEL = too little fuel.

Between the LEL and UEL = flammable range.

Above the UEL = too much fuel and insufficient oxygen.

A safety data sheet will include information on: (Page 1257)

A) brands available.

B) price.

C) purity.

D) accident release measures.

D) Accident release measures

A Safety Data Sheet (SDS) provides essential information about a hazardous chemical, including its hazards, safe handling procedures, protective equipment, and accidental release measures.

Accidental release measures explain how to respond to spills or leaks, including containment, cleanup precautions, and protective measures.

A) Brands available: An SDS focuses on chemical safety, not comparing brands or products.

B) Price: Pricing and purchasing information are not standard SDS content.

C) Purity: Although an SDS may list chemical ingredients and their concentrations, purity is not the best answer because accidental release measures are a specific required SDS topic.

Study Tip

Remember the 16 sections of an SDS. Two especially useful sections for emergency responders are:

Section 4: First-aid measures.

Section 6: Accidental release measures.

A toxic gas has been released on the first floor of a three-story building. Its density is lower than that of the ambient air. Where will it most likely be found? (Page 1265)

A) Second floor

B) Adjacent building

C) Center of town

D) Parking lot

A) Second floor

A gas with a density lower than that of the surrounding air will generally rise and accumulate in higher areas. Since the gas was released on the first floor of a three-story building, it will most likely rise toward the second floor, assuming indoor airflow and ventilation do not significantly alter its movement.

B) Adjacent building: The gas could spread to another building, but its lower density favors upward movement first under the stated conditions.

C) Center of town: This is too broad and does not account for the gas's movement within the building.

D) Parking lot: A lighter-than-air gas generally rises rather than accumulating near ground level.

Study Tip

Lighter gases rise; heavier gases tend to sink.

Lower density than air: Tends to rise.

Higher density than air: Tends to settle in low areas.

Exam shortcut: When a gas is lighter than air and released indoors, look for the higher floor. Actual gas movement also depends on ventilation, temperature, and airflow.

A toxic liquid escapes from a tanker truck, vaporizes, and spreads out evenly as it rises, forming a cone. This would be an example of which of the following? (Page 1258)

A) Container breach

B) Container failure

C) Container stress

D) Container impingement

B) Container failure

The container can no longer safely hold its contents, resulting in a hazardous-material release.

A) Container breach: Specifically refers to a hole, crack, or opening through which material escapes. The question focuses on the overall release scenario rather than describing a particular opening.

C) Container stress: Refers to forces or conditions that place strain on the container, such as heat or internal pressure.

D) Container impingement: Usually refers to a fluid or flame striking a surface; it is not the standard term for a vapor cloud dispersing from a tanker.

Study Tip

Container failure = loss of containment. A breach may cause the failure, but failure describes the broader condition.

Above its ignition temperature, a flammable liquid will ignite: (Page 1262)

A) without an ignition source.

B) from the bottom up.

C) if oxygen is absent.

D) if stirred.

A) Without an ignition source.

A flammable liquid heated above its autoignition temperature can ignite without an external ignition source, such as a spark or flame, provided sufficient oxygen is present.

B) From the bottom up: The direction of ignition is not determined simply by the liquid's temperature.

C) If oxygen is absent: Combustion generally requires oxygen or another suitable oxidizer.

D) If stirred: Stirring does not automatically cause ignition; the conditions for combustion must be met.

Study Tip

Flash point: Lowest temperature at which a liquid gives off enough vapor to ignite when an ignition source is applied.

Autoignition temperature: Temperature at which a substance can ignite without an external ignition source.

Exam shortcut: The key phrase is without an ignition source — think autoignition temperature.

Because they lack the ability to knock an electron out of its orbit, radio waves are an example of what? (Page 1270)

A) Electromagnetism

B) Gamma radiation

C) Non-ionizing radiation

D) Ionizing radiation

C) Non-ionizing radiation

Non-ionizing radiation does not have enough energy per photon to remove (knock out) an electron from an atom. Radio waves are a form of non-ionizing electromagnetic radiation because they have relatively low photon energy.

A) Electromagnetism: Electromagnetism is a fundamental interaction, and radio waves are electromagnetic waves, but this does not specifically describe their inability to ionize atoms.

B) Gamma radiation: Gamma rays are high-energy electromagnetic radiation that can ionize atoms.

D) Ionizing radiation: This radiation has sufficient energy to remove electrons from atoms or molecules.

Study Tip

Radio waves = non-ionizing;

Gamma rays = ionizing.

Non-ionizing: Radio waves, microwaves, and visible light.

Ionizing: X-rays and gamma rays.

By definition, an ion always has some: (Pages 1270-1271)

A) antidote.

B) density.

C) color.

D) charge.

D) Charge

An ion is an atom or molecule that has gained or lost one or more electrons, giving it a net electrical charge.

Positive ion (cation): Loses electrons.

Negative ion (anion): Gains electrons.

A) Antidote: An antidote is a substance used to counteract a poison; ions do not necessarily have antidotes.

B) Density: Density is a physical property of matter, not what defines an ion.

C) Color: Ions may be colorless or colored, depending on the substance.

Study Tip

An ion = an electrically charged particle.

Loses electrons → positive charge.

Gains electrons → negative charge.

Chemical and physical properties are ______ characteristics. (Page 1256)

A) qualitative

B) measurable

C) fungible

D) uncertain

B) Measurable

Chemical and physical properties are measurable characteristics that help identify and describe a substance.

Physical properties include boiling point, density, and melting point.

Chemical properties include flammability, reactivity, and corrosiveness.

These properties help hazardous materials responders identify substances and assess their risks.

A) Qualitative: Qualitative characteristics describe qualities without necessarily using numerical measurements. Some properties can be qualitative, but this is not the best answer here.

C) Fungible: Means interchangeable or replaceable with an equivalent item; it does not describe chemical or physical properties.

D) Uncertain: Properties can be determined through testing and observation; uncertainty is not their defining characteristic.

Study Tip

Properties describe and measure a substance.

Chronic health effects may result from which of the following? (Page 1273)

A) Any exposure to a hazardous material

B) A short, one-time exposure

C) Any exposure to a hazardous material without PPE

D) Multiple short-term exposures that occur over a short period of time

D) Multiple short-term exposures that occur over a short period of time

Chronic health effects develop over a prolonged period, often due to repeated or long-term exposure to hazardous substances. Depending on the chemical and dose, repeated exposures can contribute to lasting health problems, such as organ damage or certain cancers.

Important note: The wording of option D is imperfect. Chronic effects are generally associated with repeated or prolonged exposure over time, not necessarily multiple exposures within only a short period.

A) Any exposure to a hazardous material: Not every exposure causes chronic health effects; the substance, dose, and duration matter.

B) A short, one-time exposure: A single exposure is more commonly associated with acute effects, although some single exposures can cause lasting health problems.

C) Any exposure to a hazardous material without PPE: Lack of personal protective equipment increases risk, but it does not automatically cause chronic effects.

Study Tip

Acute = Immediate or short-term effects.

Chronic = Long-term or delayed effects.

Chronic health effects of hazardous materials always occur when? (Page 1273)

A) In entire families

B) Over extended periods

C) Due to a single exposure

D) In an entire town at once

B) Over extended periods

Chronic health effects develop over an extended period and may appear months or years after exposure to a hazardous material. Examples include certain cancers, chronic respiratory diseases, and long-term organ damage.

A) In entire families: Chronic effects can affect individuals; they do not have to occur throughout a family.

C) Due to a single exposure: A single exposure is more commonly associated with acute effects, although it can sometimes cause lasting damage.

D) In an entire town at once: Chronic effects do not require a community-wide exposure.

Study Tip

Acute = Appears quickly.

Chronic = Develops over time.

Compared to acute health effects, chronic health effects occur: (Page 1273)

A) despite the best efforts of physicians.

B) over longer periods of time.

C) with greater severity.

D) in fewer people.

B) Over longer periods of time

Chronic health effects develop over a long period, sometimes months or years after exposure to a hazardous material. They may result from repeated exposure or, in some cases, a single exposure with lasting consequences.

In contrast, acute health effects occur rapidly, often shortly after exposure.

A) Despite the best efforts of physicians: This is not a defining characteristic of chronic health effects.

C) With greater severity: Chronic effects are not always more severe than acute effects; severity depends on the substance and exposure.

D) In fewer people: Either acute or chronic effects can affect many or few people, depending on the exposure circumstances.

Study Tip

Acute = immediate

Chronic = prolonged.

Acute: Dizziness or burns shortly after exposure.

Chronic: Long-term respiratory problems or certain cancers that develop over time.

Contact by people, animals, the environment, property, or equipment with a hazardous material/WMD is called what? (Page 1272)

A) Secondary contamination

B) Hazard

C) Contamination

D) Exposure

D) Exposure

Exposure occurs when a person, animal, object, or the environment comes into contact with a hazardous material.

A) Secondary contamination: Occurs when hazardous material is transferred from a contaminated person or object to another person or object.

B) Hazard: A source of potential harm, such as a toxic chemical or radioactive substance.

C) Contamination: Refers to hazardous material being deposited on or entering a person, object, or environment.

Study Tip

Exposure = contact with a hazardous material.

Contamination = hazardous material is present on or in something.

Secondary contamination = contamination spreads to another person or object.

Contamination of an individual at an event scene implies that the individual: (Page 1272)

A) may contaminate others.

B) caused the incident.

C) will die.

D) did something unsafe.

A) May contaminate others.

A contaminated individual may transfer hazardous material to other people, equipment, or surfaces through direct contact. This is called secondary contamination.

For example, a person exposed to a toxic chemical may carry residue on their clothing or skin and transfer it to a family member or first responder.

B) Caused the incident: Being contaminated does not mean the individual caused the hazardous materials release.

C) Will die: Contamination does not automatically mean death. The outcome depends on the substance, dose, exposure route, and treatment.

D) Did something unsafe: A person can become contaminated through circumstances beyond their control, such as being near an accidental release.

Study Tip

Contaminated people can become sources of secondary contamination.

Different forms of the same atom are known as what? (Page 1271)

A) Betas

B) Isotopes

C) Ions

D)Gammas

B) Isotopes

Isotopes are different forms of the same chemical element that have the same number of protons but different numbers of neutrons.

For example, carbon-12 and carbon-14 are isotopes of carbon. Both have 6 protons, but they have different numbers of neutrons.

A) Betas: Beta particles are high-energy electrons or positrons emitted during certain types of radioactive decay.

C) Ions: Ions are atoms or molecules that have gained or lost electrons, giving them an electrical charge.

D) Gammas: Gamma rays are high-energy electromagnetic radiation emitted during nuclear processes.

Study Tip

Isotopes = Different numbers of neutrons.

Ions = Different numbers of electrons.

Protons = Determine the element.

For a liquid with a low flash pressure, which of the following is true of its vapor pressure? (Page 1263)

A) The vapor pressure is higher than the flash pressure.

B) The vapor pressure is lower than the flash pressure.

C) The vapor pressure becomes more variable with ambient pressure.

D) The vapor pressure is hard to predict.

A) The vapor pressure is higher than the flash pressure.

Vapor pressure describes how readily a liquid evaporates at a given temperature. Liquids with higher vapor pressure generally evaporate more readily.

Note: Flash point and vapor pressure are different properties, so vapor pressure is not always higher or lower than a "flash pressure." The wording of the question is technically imprecise.

B) The vapor pressure is lower than the flash pressure: Flash pressure is not a standard property directly comparable to vapor pressure.

C) The vapor pressure becomes more variable with ambient pressure: Vapor pressure primarily depends on temperature and the liquid's properties.

D) The vapor pressure is hard to predict: Vapor pressure can be measured or estimated using known physical properties and temperature.

Study Tip

Flash point: The lowest temperature at which a liquid gives off enough vapor to ignite when an ignition source is present.

Vapor pressure: Indicates how readily a liquid evaporates.

Boiling point: The temperature at which vapor pressure equals the surrounding pressure.

Given the following flammable ranges, which one is generally the most dangerous? (Page 1263)

A) 2.5-9.5%

B) 5.0-15.0%

C) 0.7-4.0%

D) 4.0-19.5%

D) 4.0-19.5%

A flammable range is the concentration range of a vapor or gas in air within which it can ignite.

D has the widest flammable range, spanning 15.5 percentage points. Generally, a wider flammable range means the gas or vapor can ignite across a broader range of concentrations, making it potentially more hazardous.

How does radiation damage a cell? (Page 1271)

A) It bursts the cell membrane.

B) It burns the cell.

C) It ionizes the atoms and changes their behavior.

D) It kills the cell.

C) It ionizes the atoms and changes their behavior.

Ionizing radiation damages cells by removing electrons from atoms and molecules, a process called ionization. This can damage DNA and other cellular structures, potentially causing mutations, impaired cell function, or cell death.

A) It bursts the cell membrane: Radiation can damage cell membranes, but bursting the membrane is not the primary mechanism.

B) It burns the cell: Radiation damage is not necessarily a thermal burn; it can occur through ionization without heating the tissue.

D) It kills the cell: Cell death can result from radiation exposure, but some cells survive, sometimes with DNA damage or mutations.

Study Tip

Ionizing radiation removes electrons, which can damage DNA.

Possible outcomes include cell repair, cell death, or mutations in surviving cells.

How is pH determined in the field? (Page 1268)

A) By adding baking soda

B) pH paper

C) Using taste

D) By watching the reaction with gasoline

B) pH paper

pH paper is used in the field to estimate whether a substance is acidic, neutral, or alkaline (basic). When dipped into a liquid, the paper changes color, which is compared with a color chart to determine its approximate pH.

pH below 7: Acidic

pH of 7: Neutral

pH above 7: Alkaline (basic)

A) By adding baking soda: Baking soda can neutralize some acids, but it does not reliably measure pH.

C) Using taste: Tasting an unknown substance is dangerous and must never be used to identify hazardous materials.

D) By watching the reaction with gasoline: This is unsafe and does not provide a reliable pH measurement.

Study Tip

pH paper = quick field test for acids and bases.

Use the scale:

0-6: Acidic

7: Neutral

8-14: Basic

If a chemical name is not contained in the mnemonic 4H MEDIC ANNA it is safe to assume what about its physical properties? (Page 1266)

A) It is heavier than air.

B) It is soluble in water.

C) It is reactive in air.

D) It is radioactive.

A) It is heavier than air.

The mnemonic 4H MEDIC ANNA helps firefighters remember certain hazardous chemicals that are lighter than air. If a chemical is not included in this mnemonic, it is generally assumed to be heavier than air for initial hazard assessment purposes. However, always verify the chemical's actual properties using the Safety Data Sheet (SDS) and appropriate hazardous materials references.

B) It is soluble in water. The mnemonic does not indicate whether a chemical dissolves in water.

C) It is reactive in air. The mnemonic does not identify chemicals based on their reactivity with air.

D) It is radioactive. Radioactivity is unrelated to this mnemonic.

Study Tip:

Remember that 4H MEDIC ANNA is associated with gases lighter than air. For exam purposes, if a chemical is not on the list, the expected answer is that it is heavier than air.

If a heavy toxic gas were released into an area with varied topography, where would it end up? (Page 1257)

A) Raised roadway

B) Mountain slope

C) Hilltop

D) River valley

D) River valley.

Heavy toxic gases tend to sink and accumulate in low-lying areas because they are denser than the surrounding air. In varied terrain, a heavy gas may collect in river valleys, depressions, and other low spots, creating dangerous concentrations.

A) Raised roadway: Elevated areas are less likely to collect heavy gases than low-lying areas.

B) Mountain slope: A slope is generally higher than a valley, so gas is more likely to move downhill.

C) Hilltop: Hilltops are elevated and typically less likely to trap heavy gases.

Study Tip:

Heavy gases settle low; lighter gases rise high.

Think of a heavy gas flowing downhill and collecting in a valley, much like water. Keep in mind that wind, temperature, and terrain can affect actual gas movement.

If a material has a lethal concentration (LC) value, what is its state of matter? (Page 1275)

A) Gas

B) Liquid

C) Solid

D) Plasma

A) Gas

A lethal concentration (LC) value measures the concentration of a substance in the air that causes death in a specified percentage of test organisms over a specified period of exposure. It is commonly used for toxic gases and vapors and is often expressed in parts per million (ppm) or milligrams per cubic meter (mg/m³).

B) Liquid: Liquids are typically evaluated using lethal dose measurements when exposure occurs through ingestion or skin contact, although liquid substances can produce toxic vapors.

C) Solid: Solids are often evaluated by lethal dose when exposure occurs through ingestion or other routes, though airborne solid particles can also be hazardous.

D) Plasma: Plasma is an ionized state of matter and is not the state typically associated with LC toxicity measurements.

Study Tip:

LC = Lethal Concentration, which measures a toxic substance's concentration in air, while LD = Lethal Dose, which measures the amount of a substance that causes death.

Exam shortcut: LC = concentration; LD = dose.

If a released product is floating on a body of water, what can be inferred about its specific gravity? (Page 1266)

A) It is greater than 10.

B) It is equal to 1.

C) It is less than 1.

D) It is greater than 1.

C) It is less than 1.

Specific gravity compares a substance's density to the density of water. If a product floats on water, it generally has a specific gravity less than 1, meaning it is less dense than water.

A) It is greater than 10. A substance this dense would generally sink in water.

B) It is equal to 1. A substance with a specific gravity of 1 has approximately the same density as water and would be neutrally buoyant under ideal conditions.

D) It is greater than 1. A substance denser than water generally sinks rather than floats.

Study Tip:

Less than 1 = floats; greater than 1 = sinks.

Think of oil floating on water because oil is less dense than water.

If carbon disulfide is released near a pond, where will it end up? (Page 1266)

A) Mixed in the water column

B) High in the atmosphere

C) Pond bottom

D) On the grass next to the pond

C) Pond bottom

Carbon disulfide has a specific gravity greater than 1, meaning it is denser than water. If released into a pond, it will tend to sink below the water's surface and collect near the bottom.

A) Mixed in the water column: Carbon disulfide has low solubility in water, so it does not readily mix throughout the water.

B) High in the atmosphere: Carbon disulfide vapor is heavier than air, so it does not naturally rise high into the atmosphere. However, wind and other conditions can disperse it.

D) On the grass next to the pond: This is not the expected outcome if the product is released directly into the pond.

Study Tip:

Carbon disulfide sinks in water because its specific gravity is greater than 1. For hazardous materials questions, consider both the substance's density relative to water and its vapor density relative to air.

If the flash point of gasoline is -45ºF, at what temperature would a flame near a pool of gasoline cause a flash fire? (Page 1262)

A) -50ºF (-45.5ºC)

B) -40ºF (-40ºC)

C) -47ºF (-43.9ºC)

D) -51ºF (-46.1ºC)

B) -40°F (-40°C)

The flash point is the lowest temperature at which a liquid produces enough vapor to ignite when exposed to an ignition source.

Gasoline has a flash point of -45°F. At temperatures above this point, gasoline can produce enough flammable vapor for a flame to ignite it and cause a flash fire. Since -40°F is warmer than -45°F, the gasoline can ignite under the right conditions.

Study Tip

Flash point = minimum temperature for ignitable vapor.

If you open a cylinder of a gas with a vapor density of 1.2, where will the gas go? (Page 1266)

A) Middle of the air column in the room

B) Near the nozzle

C) Ceiling

D) Cylinder base

D) Cylinder base

Vapor density compares the weight of a gas or vapor to the weight of an equal volume of air. Air has a vapor density of 1.0.

Since this gas has a vapor density of 1.2, it is heavier than air and will tend to sink and collect in low-lying areas, such as near the base of the cylinder.

A) Middle of the air column in the room: The gas is heavier than air, so it tends to settle lower rather than remain suspended in the middle.

B) Near the nozzle: The gas initially exits the nozzle, but its vapor density determines its tendency to move relative to air.

C) Ceiling: Gases lighter than air tend to rise toward the ceiling, not heavier gases.

Study Tip

Vapor density greater than 1 = heavier than air; less than 1 = lighter than air.

Greater than 1: Think down.

Less than 1: Think up.

Keep in mind that wind, ventilation, and temperature can affect how a released gas actually moves.

If you pour gasoline into a river, it will: (Page 1266)

A) burn.

B) float.

C) sink.

D) evaporate.

B) Float.

Gasoline has a specific gravity of less than 1, meaning it is less dense than water. If gasoline is poured into a river, it will generally float on the water's surface. Gasoline also evaporates readily, creating flammable vapors that can pose a serious fire hazard.

A) Burn: Gasoline can burn if its vapors encounter an ignition source, but burning is not what automatically happens when gasoline enters a river.

C) Sink: Gasoline is less dense than water, so it generally does not sink.

D) Evaporate: Gasoline evaporates readily, but the question asks what happens when it is poured into a river. The expected answer is that it floats.

Study Tip

Specific gravity compares a substance's density to water.

Less than 1 = floats

Greater than 1 = sinks

Think of oil or gasoline floating on water!

Injury due to radiation exposure can be mitigated by increasing which of these? (Page 1270)

A) The concentration of the chemical emitting the radiation

B) Distance from the source

C) The time used for cleanup

D) The number of EMTs working

B) Distance from the source

Radiation exposure can be reduced by following three basic principles: time, distance, and shielding.

Time: Minimize the time spent near the radiation source.

Distance: Increase your distance from the radiation source to reduce exposure.

Shielding: Place appropriate protective material between yourself and the source.

Increasing your distance reduces the amount of radiation you receive.

A) The concentration of the chemical emitting the radiation: Increasing the concentration could increase the radiation hazard rather than reduce it.

C) The time used for cleanup: Spending more time near a radiation source increases cumulative exposure. Cleanup should be performed only by appropriately trained and equipped personnel.

D) The number of EMTs working: Adding more EMTs does not directly reduce radiation exposure. Responders still need proper radiation safety procedures.

Study Tip

Remember the radiation safety rule:

Time, Distance, Shielding.

Spend less time near the source.

Keep more distance from the source.

Use appropriate shielding.

Exam shortcut: More distance = less radiation exposure.

Of the following products, which would tend to have a higher ignition temperature? (Page 1262)

A) Diesel

B) Corn oil

C) Kerosene

D) Gasoline

D) Gasoline

Of the states of matter, which one is often referred to as a vapor? (Page 1257)

A) Solid

B) Plasma

C) Gas

D) Liquid

C) Gas

A vapor is the gaseous form of a substance that is normally a liquid or solid under ordinary conditions. In hazardous materials response, the terms gas and vapor are often used similarly when discussing airborne substances.

For example, gasoline evaporates and releases gasoline vapor into the air. These vapors can be highly flammable.

A) Solid: Solids have a definite shape and volume; they are not vapors.

B) Plasma: Plasma is an ionized state of matter containing charged particles, such as in lightning.

D) Liquid: Liquids have a definite volume but take the shape of their container. They can evaporate to produce vapor.

Study Tip

Remember the basic states of matter:

-Solid: Ice

-Liquid: Water

-Gas/vapor: Water vapor

-Plasma: Lightning

Exam shortcut: When a liquid evaporates, it produces vapor that mixes with the surrounding air.

Radiation is always: (Pages 1269-1270)

A) found in hospital incidents.

B) lethal.

C) transmitted energy.

D) regulated by OSHA.

C) Transmitted energy.

Radiation is energy that travels through space or matter in the form of waves or particles. It can come from natural sources, such as the sun, or artificial sources, such as X-ray machines.

Radiation is not always dangerous. The level of risk depends on the type of radiation, its intensity, and the duration of exposure.

A) Found in hospital incidents: Radiation can be present in hospitals, but it also occurs in many other environments.

B) Lethal: Not all radiation is lethal. The effects depend on the type and amount of exposure.

D) Regulated by OSHA: OSHA regulates certain workplace radiation hazards, but radiation itself is not defined by whether it is regulated.

Study Tip

Radiation = energy traveling through space or matter.

For hazardous materials exams, know the difference between:

Radiation: Energy traveling in waves or particles.

Radioactive material: A substance that emits radiation.

Not all radiation exposure is deadly, but appropriate precautions are essential.

The lowest temperature at which a liquid can completely turn into a gas is its: (Page 1264)

A) boiling point.

B) flash point.

C) atmospheric pressure.

D) vapor pressure.

A) Boiling point.

The boiling point is the temperature at which a liquid boils and changes into a gas throughout the liquid. At this temperature, its vapor pressure equals the surrounding pressure.

For example, water boils at 212°F (100°C) at standard atmospheric pressure.

B) Flash point: The lowest temperature at which a liquid produces enough vapor to ignite briefly when exposed to an ignition source.

C) Atmospheric pressure: The pressure exerted by the atmosphere; it affects a liquid's boiling point but is not a temperature.

D) Vapor pressure: The pressure exerted by a vapor above its liquid or solid when in equilibrium; it is not a temperature.

Study Tip

Remember these three important terms for your hazardous materials exam:

-Boiling point = Liquid boils into gas.

-Flash point = Vapor can ignite.

-Vapor pressure = Pressure exerted by vapor.

Exam shortcut: If the question asks about the temperature at which a liquid boils, think boiling point!

To obtain chemical safety information by phone, in Canada, call the: (Page 1257)

A) Canadian Transport Emergency Centre.

B) Chemical Transportation Emergency Center.

C) Occupational Safety and Health Administration.

D) Emergency Transportation System for the Chemical Industry, Mexico.

A) Canadian Transport Emergency Centre.

The Canadian Transport Emergency Centre (CANUTEC) is operated by Transport Canada and provides 24-hour emergency assistance and technical information about dangerous goods involved in transportation incidents.

B) Chemical Transportation Emergency Center: Not the official name of Canada's service.

C) Occupational Safety and Health Administration: OSHA is a U.S. agency responsible for workplace safety and health.

D) Emergency Transportation System for the Chemical Industry, Mexico: Not the Canadian emergency information service.

Study tip:

Remember, CANUTEC = Canada's dangerous goods emergency information service. It helps emergency responders manage incidents involving hazardous materials during transportation.

Vaporization of ethanol produces what? (Page 1257)

A) Plasma

B) Gas

C) Liquid

D) Solid

B) Gas

Vaporization is the physical process in which a liquid changes into a gas. When ethanol vaporizes, it changes from liquid ethanol into ethanol vapor.

A) Plasma: An ionized state of matter containing charged particles.

C) Liquid: The original state of ethanol before vaporization.

D) Solid: A frozen state of matter.

Study tip:

Remember, vaporization = liquid to gas. This is especially important in hazardous materials response because ethanol vapor is flammable and can ignite when mixed with air in the right concentrations.

What are particles with no charge that are located in the nucleus called? (Page 1270)

A) Neutrons

B) Nuclide

C) Electrons

D) Protons

A) Neutrons

Neutrons are subatomic particles that have no electrical charge and are located in an atom's nucleus.

B) Nuclide: A specific type of atom characterized by its numbers of protons and neutrons.

C) Electrons: Negatively charged particles found outside the nucleus.

D) Protons: Positively charged particles located in the nucleus.

Study tip:

Remember the three basic subatomic particles:

Protons = positive (+)

Neutrons = neutral (0)

Electrons = negative (−)

What is the boiling point of water at sea level? (Page 1265)

A) 212ºF (100ºC)

B) 112ºF (44.4ºC)

C) 100ºF (37.8ºC)

D) 312ºF (155ºC)

A) 212ºF (100ºC)

At sea level, water boils at 212°F (100°C) under normal atmospheric pressure. At this temperature, water changes from a liquid into a gas.

Study tip:

Remember, water boils at 212°F (100°C) and freezes at 32°F (0°C) at normal atmospheric pressure. Higher elevations have lower atmospheric pressure, so water boils at a lower temperature.

What is the flash point of water? (Page 1264)

A) The same as for ethanol

B) Half of its boiling point at a given atmospheric pressure

C) Water does not have a flash point.

D) 110ºF (43.3ºC)

C) Water does not have a flash point.

A flash point is the lowest temperature at which a liquid gives off enough vapor to ignite when exposed to an ignition source under specified test conditions. Water is not flammable and does not produce combustible vapor, so it does not have a flash point.

A) The same as for ethanol: Ethanol is flammable; water is not.

B) Half of its boiling point at a given atmospheric pressure: There is no such rule for determining flash point.

D) 110°F (43.3°C): This is not the flash point of water.

Study tip:

Remember, flash point applies to flammable or combustible liquids, not water.

What is the specific gravity of water? (Page 1266)

A) 0.8

B) 1.5

C) 1.0

D) 2.0

C) 1.0

What is the term for the small vapor space above a liquid in a closed container? (Page 1263)

A) Cold zone

B) Blankspace

C) Headspace

D) Dead zone

C) Headspace

Headspace is the space above the liquid inside a closed container. This space often contains vapor from the liquid, which can create pressure or a flammable atmosphere depending on the substance.

A) Cold zone: A designated safe area at a hazardous materials incident.

B) Blankspace: Not the standard technical term.

D) Dead zone: A term used in other contexts, but not for the vapor space above a liquid in a container.

Study tip:

Remember, headspace = the space above the liquid inside a container, where vapors can accumulate.

What is the vapor density of propane? (Page 1266)

A) 0.83

B) 2.01

C) 1.0

D) 1.55

D) 1.55

What must responders do when using detection and monitoring equipment? (Page 1269)

A) Use it as a tool, but trust your gut instinct.

B) Make decisions based on the information it is providing.

C) Monitoring and detection equipment are inherently inaccurate.

D) The monitor will alarm when there is a problem.

B) Make decisions based on the information it is providing.

Responders must use detection and monitoring equipment to help assess hazards and make informed decisions at an incident. The readings help identify dangerous conditions, determine appropriate protective measures, and guide response actions.

A) Use it as a tool, but trust your gut instinct: Decisions should be based on training, procedures, and reliable information—not instinct alone.

C) Monitoring and detection equipment are inherently inaccurate: Equipment can have limitations, but properly maintained and calibrated instruments provide valuable information.

D) The monitor will alarm when there is a problem: Not every hazardous condition triggers an alarm. Settings, detection limits, and equipment limitations can affect alarms.

Study tip:

Remember, use monitoring equipment readings to guide decisions, but understand the equipment's limitations. Never assume that no alarm means no hazard.

What term describes the characteristics of a WMD or a material that are measurable, such as, vapor density, specific gravity, and solubility? (Page 1256)

A) Chemical and physical properties

B) Sample profile

C) Unique characteristics

D) Material properties

A) Chemical and physical properties

Chemical and physical properties are measurable characteristics used to identify a substance and predict how it will behave during a hazardous materials incident.

Examples include:

-Vapor density: Indicates whether a vapor is heavier or lighter than air.

-Specific gravity: Compares a substance's density with that of a reference substance, usually water for liquids and solids.

-Solubility: Describes how well a substance dissolves in another substance.

B) Sample profile: Not the standard term for these measurable properties.

C) Unique characteristics: Too general and does not specifically identify chemical and physical properties.

D) Material properties: A broad term, but A is the more precise answer for this question.

Study tip:

Remember, physical properties describe measurable characteristics, while chemical properties describe how a substance reacts or changes chemically.

What type of exposure causes immediately observable symptoms such as eye irritation, coughing, or skin burns? (Page 1273)

A) Subacute

B) Accidental

C) Chronic

D) Acute

D) Acute

An acute exposure occurs over a short period and can cause symptoms that appear quickly, such as eye irritation, coughing, or chemical burns on the skin.

A) Subacute: Generally refers to exposure or effects occurring over an intermediate period.

B) Accidental: Describes how an exposure happens, not its duration.

C) Chronic: Involves prolonged or repeated exposure over time, often leading to longer-term health effects.

Study tip:

Remember, acute = short-term exposure; chronic = long-term or repeated exposure. Acute exposure can cause immediate symptoms, although some serious effects may be delayed.

What type of material can cause an immune system response when inhaled or absorbed through the skin? (Page 1273)

A) Toxin

B) Sensitizer

C) Pathogen

D) Carcinogen

B) Sensitizer

A sensitizer is a substance that can cause the immune system to become overly sensitive after exposure. Once sensitized, a person may experience an allergic reaction after later exposure to the same substance, even at a low concentration.

Sensitizers can enter the body through inhalation or skin contact.

A) Toxin: A poisonous substance that can cause harm to the body.

C) Pathogen: A microorganism, such as a bacterium or virus, that can cause disease.

D) Carcinogen: A substance that can cause cancer.

Study tip:

Remember, sensitizer = triggers an immune response or allergic reaction. Think of substances that can cause occupational asthma or allergic skin reactions.

When a situation exceeds a responder's training or ability to solve it, what may exist? (Page 1272)

A) No-go situation

B) Offensive operation

C) Defensive operation

D) Critical situation

A) No-go situation

A no-go situation exists when an incident exceeds a responder's training, experience, or capabilities. Responders should not attempt tasks they are not qualified or equipped to perform.

B) Offensive operation: An operation in which responders take direct action to control or stop the hazard.

C) Defensive operation: An operation focused on protecting people, property, and the environment without directly stopping the release.

D) Critical situation: A serious or urgent incident, but not the specific term for an incident beyond a responder's capabilities.

Study tip:

Remember, if the hazard exceeds your training or capabilities, don't go in. Recognize your limits, maintain a safe distance, and request appropriately trained and equipped personnel.

When assessing the risk of a flammable liquid catching fire, which physical property is most helpful? (Page 1261)

A) Solubility

B) Flash point

C) Freezing point

D) Vapor pressure

B) Flash point

The flash point is the lowest temperature at which a liquid gives off enough vapor to ignite when exposed to an ignition source under specified test conditions.

A lower flash point generally means a liquid can ignite more easily at lower temperatures, making this property especially useful when assessing fire hazards.

A) Solubility: Describes how well a substance dissolves in another substance.

C) Freezing point: The temperature at which a liquid changes into a solid.

D) Vapor pressure: Indicates how readily a liquid vaporizes, which also affects fire risk but is not the best answer here.

Study tip:

Remember, flash point = how easily a liquid can ignite at a given temperature. Lower flash point generally means greater fire risk at ordinary temperatures.

When discussing a container, the terms thermal, chemical, and mechanical all refer to what? (Page 1258)

A) Failure

B) Closure

C) Rupture

D) Stress

D) Stress

Thermal, chemical, and mechanical stress are the three main types of stress that can cause a hazardous materials container to weaken or fail.

A) Failure: The result of stress that causes a container to lose its integrity.

B) Closure: The lid, cap, or other device used to seal a container.

C) Rupture: A break or split in a container, often caused by excessive stress.

Study tip:

Remember MCT = Mechanical, Chemical, Thermal. These three types of stress can damage a container and potentially cause a hazardous material to escape.

When discussing pH, which material has a high amount of hydroxyl (OH-) ions? (Page 1267)

A) Flammable liquids

B) Bases

C) Acids

D) Fuels

B) Bases

Bases have properties associated with hydroxide (OH⁻) ions and typically have a pH greater than 7. The higher the pH, the more alkaline the solution is.

A) Flammable liquids: Classified by their ability to ignite, not their hydroxide ion content.

C) Acids: Have a higher concentration of hydrogen ions (H⁺) and a pH below 7.

D) Fuels: Classified by their ability to burn, not their pH.

Study tip:

Remember, acids = low pH; bases = high pH. Bases are associated with hydroxide (OH⁻) ions, while acids are associated with hydrogen (H⁺) ions.

When discussing toxic chemical solutions, strength and concentration are: (Page 1269)

A) set by the Occupational Safety and Health Administration.

B) legally defined terms.

C) sometimes very different.

D) the same thing.

C) sometimes very different.

Strength and concentration are not necessarily the same thing. Concentration refers to how much of a substance is present in a solution, while strength refers to how strongly an acid or base behaves chemically.

For example, a concentrated weak acid may have a higher concentration than a dilute strong acid, even though the strong acid ionizes more readily in water.

A) Set by OSHA: OSHA regulates workplace safety but does not define these terms as identical.

B) Legally defined terms: These are chemical concepts, not simply legal classifications.

D) The same thing: Strength and concentration describe different properties.

Study tip:

Remember, concentration = how much is present; strength = how strongly an acid or base behaves chemically.

When talking about toxic materials and hazard, the key concept is always: (Page 1272)

A) capability.

B) color.

C) volatility.

D) water solubility.

A) capability.

When evaluating toxic materials and hazards, the key concept is a substance's capability to cause harm. Toxicity depends on factors such as the substance, the dose, the route of exposure, and the duration of exposure.

B) Color: A chemical's color does not determine how toxic it is.

C) Volatility: Describes how readily a substance vaporizes, which can affect exposure risk but does not determine toxicity by itself.

D) Water solubility: Describes how well a substance dissolves in water, not its ability to cause harm.

Study tip:

Remember, toxicity is about a substance's ability to cause harm. A substance's physical properties can affect exposure, but toxicity determines its potential to injure or kill.

When temperature increases, the production of vapor from the surface of a liquid will do what? (Page 1262)

A) Decrease

B) Stay the same

C) Depend on the material

D) Increase

D) Increase

As temperature increases, more molecules at the surface of a liquid gain enough energy to escape into the air as vapor. This increases the rate of evaporation and generally raises the liquid's vapor pressure.

A) Decrease: Higher temperatures generally increase vapor production.

B) Stay the same: Vapor production changes as temperature changes.

C) Depend on the material: The material affects how much vapor is produced, but the general relationship is that higher temperatures increase vapor production.

Study tip:

Remember, higher temperature = more vapor = potentially greater fire or explosion risk when dealing with flammable liquids.

When water freezes it turns from a liquid to a solid. This process describes what type of change? (Page 1260)

A) Covalent bonding

B) Electron transfer

C) Chemical change

D) Physical change

D) Physical change

When water freezes, it changes from a liquid to a solid, but its chemical composition remains the same: H₂O. No new substance is formed, so this is a physical change.

A) Covalent bonding: Describes atoms sharing electrons to form chemical bonds.

B) Electron transfer: Occurs when electrons move from one atom or substance to another.

C) Chemical change: Involves a chemical reaction that forms one or more new substances.

Study tip:

Remember, a physical change changes the form or state of a substance, while a chemical change creates a new substance. Examples of physical changes include freezing, melting, and evaporation.

Which chemical factor is most responsible for corrosivity? (Page 1267)

A) pH

B) Boiling point

C) Vapor pressure

D) Water solubility

A) pH

pH is a key factor used to assess the corrosivity of acids and bases. The pH scale ranges from 0 to 14. Strong acids have a low pH, while strong bases have a high pH. Both can cause severe chemical burns and damage materials.

Why the other answers are incorrect:

B) Boiling point: The temperature at which a liquid changes into a gas.

C) Vapor pressure: The pressure exerted by a vapor above its liquid.

D) Water solubility: Describes how well a substance dissolves in water.

Study tip:

Remember, pH helps indicate acidity and alkalinity, which are important clues to corrosivity. A very low or very high pH generally indicates a greater potential for corrosive damage, although pH alone does not determine how corrosive every chemical is.

Which of the following can be used to knock down clouds of toxic gas during an incident? (Page 1267)

A) Ventilation exhaust fans

B) Flames

C) Fog streams from handlines

D) Carbon dioxide extinguishers

C) Fog streams from handlines

Fog streams from handlines can sometimes be used to knock down or disperse clouds of toxic gas or vapor. The water droplets may absorb or capture certain water-soluble gases, helping reduce their airborne concentration.

A) Ventilation exhaust fans: May move hazardous gases and spread contamination rather than control the cloud.

B) Flames: Can ignite flammable gases and create additional hazards.

D) Carbon dioxide extinguishers: Are designed primarily to extinguish certain types of fires, not control toxic gas clouds.

Study tip:

Remember, water fog can help control certain toxic gas clouds, but it is not effective for every chemical. Water application can also spread contamination or create hazardous runoff, so only trained HazMat personnel should use it under an appropriate response plan.

Which of the following chemicals may lead to pulmonary edema? (Page 1272)

A) Pure oxygen

B) Carbon dioxide

C) Carbon monoxide

D) Nitrogen dioxide

D) Nitrogen dioxide

Nitrogen dioxide (NO₂) is a toxic respiratory irritant that can damage lung tissue and cause pulmonary edema, which is the buildup of fluid in the lungs. Symptoms may be delayed, so a person can initially feel fine even after a dangerous exposure.

A) Pure oxygen: Can cause lung damage at high concentrations or with prolonged exposure, but it is not the best answer here.

B) Carbon dioxide: Primarily causes oxygen displacement, headache, confusion, and potentially suffocation at high concentrations.

C) Carbon monoxide: Interferes with the blood's ability to transport oxygen, potentially causing tissue damage and death.

Study tip:

Remember, nitrogen dioxide damages the respiratory system and can cause pulmonary edema. After suspected exposure, seek immediate medical evaluation, even if symptoms seem mild.

Which of the following definitions is the median lethal dose of a toxic material that is required to kill half of the members of a tested population? (Page 1275)

A) LC50

B) LDHi

C) LD100

D) LD50

D) LD50

LD50 (Median Lethal Dose) is the dose of a toxic substance expected to cause death in 50% of a tested population under specified experimental conditions. The dose is typically expressed relative to body weight, such as milligrams per kilogram (mg/kg).

A) LC50: Median lethal concentration—the concentration of a substance in air or water that kills 50% of a test population over a specified exposure period.

B) LDHi: Refers to the highest reported dose associated with a lethal effect, not the dose that kills 50% of a population.

C) LD100: The lethal dose expected to kill 100% of the tested population under specified conditions.

Study Tip

D = Dose

C = Concentration.

LD50: Dose that kills 50%.

LC50: Concentration that kills 50%.

Which of the following describes the pressure exerted from the surface of a liquid? (Page 1263)

A) Atmospheric pressure

B) Gas pressure

C) Vapor pressure

D) Head pressure

C) Vapor pressure

Vapor pressure is the pressure exerted by a vapor above its liquid in a closed container when the vapor and liquid are in equilibrium at a given temperature.

A liquid with high vapor pressure evaporates more readily, which can increase the risk of flammable or toxic vapors accumulating.

A) Atmospheric pressure: The pressure exerted by the surrounding atmosphere.

B) Gas pressure: A general term for pressure exerted by a gas.

D) Head pressure: Pressure exerted by the weight of a column of liquid.

Study tip:

emember, vapor pressure relates to a liquid's tendency to evaporate. Higher temperatures generally increase vapor pressure.

Which of the following is a carcinogen found in most fire smoke? (Page 1271)

A) Carbon dioxide

B) Sugar

C) Water vapor

D) Soot

D) Soot

Soot consists of fine particles produced by incomplete combustion. Fire smoke can contain soot carrying carcinogenic substances, such as polycyclic aromatic hydrocarbons (PAHs), which can increase the risk of cancer.

A) Carbon dioxide: A product of combustion that can be dangerous at high concentrations, but it is not classified as a carcinogen.

B) Sugar: Not generally considered a carcinogen in this context.

C) Water vapor: A common product of combustion that is not a carcinogen.

Study tip:

Remember, soot and fire smoke can contain cancer-causing substances. Always use appropriate respiratory protection when operating in smoke-filled environments.

Which of the following is a chemical in fire smoke that affects the body's ability to transport oxygen? (Page 1271)

A) Carbon monoxide

B) Chlorine

C) Soot

D) Formaldehyde

A) Carbon monoxide

Carbon monoxide (CO) is a colorless, odorless, toxic gas produced by incomplete combustion. It binds to hemoglobin in red blood cells much more strongly than oxygen does, preventing the blood from transporting enough oxygen to the body's tissues.

B) Chlorine: A toxic gas that primarily damages the eyes and respiratory tract.

C) Soot: Fine particles that can irritate and damage the respiratory system.

D) Formaldehyde: A toxic chemical that irritates the eyes, skin, and respiratory tract.

Study tip:

Remember, carbon monoxide interferes with oxygen transport in the blood. It's especially dangerous because you cannot see or smell it.

Which of the following is a flammable concentration of natural gas in ambient air? (Page 1269)

A) 8%

B) 4%

C) 30%

D) 16%

A) 8%

Which of the following is a strongly acidic pH? (Page 1268)

A) 11

B) 7

C) 6

D) 2

D) 2

The pH scale ranges from 0 to 14 and measures how acidic or basic a substance is.

pH 0-3: Strongly acidic

pH 7: Neutral

pH 8-14: Basic (alkaline)

A) 11: Basic or alkaline.

B) 7: Neutral.

C) 6: Slightly acidic, but not strongly acidic.

D) 2: Strongly acidic.

Study tip:

Remember, low pH = acid, pH 7 = neutral, and high pH = base. The farther the pH is below 7, the more acidic the substance is.

Which of the following is a substance capable of dissolving or dispersing another substance? (Page 1267)

A) Specific gravity

B) Solution

C) Solvent

D) Solute

C) Solvent

A solvent is a substance capable of dissolving or dispersing another substance. For example, water is a common solvent because it can dissolve substances such as salt and sugar.

A) Specific gravity: The ratio of a substance's density to the density of a reference substance, usually water for liquids and solids.

B) Solution: A uniform mixture formed when a solute dissolves in a solvent.

D) Solute: The substance that is dissolved in a solvent.

Study tip:

Remember, solvent dissolves, solute gets dissolved, and solution is the mixture.

Which of the following is an example of a chemical change? (Page 1261)

A) Steel rusting

B) Propane boiling from liquid to gas

C) Dry ice converting from solid directly to gas

D) Water freezing from liquid to solid

A) Steel rusting

Steel rusting is a chemical change because iron reacts with oxygen and moisture to form iron oxide (rust), which is a new substance.

B) Propane boiling from liquid to gas: A physical change because only the state of matter changes.

C) Dry ice converting from solid directly to gas: A physical change called sublimation.

D) Water freezing from liquid to solid: A physical change because water remains H₂O.

Study tip:

Remember, chemical change = a new substance forms, while physical change = the substance changes form or state but remains chemically the same.

Which of the following is an example of a substance that reacts adversely with water? (Page 1267)

A) Vinegar

B) Gasoline

C) Milk

D) Sulfuric acid

D) Sulfuric acid

Sulfuric acid reacts with water and releases a large amount of heat. This reaction is highly exothermic and can cause the mixture to heat rapidly, splatter, and cause severe chemical burns.

A) Vinegar: Mixes readily with water without a dangerous reaction under ordinary conditions.

B) Gasoline: Does not mix well with water and generally floats on its surface, but it does not react adversely with water.

C) Milk: Mixes with water without a dangerous reaction under ordinary conditions.

Study tip:

Remember, always add acid to water—not water to acid when following an approved procedure, because adding water to concentrated acid can cause dangerous splashing from rapid heat release. At a hazardous materials incident, never attempt to mix or dilute an unknown chemical; follow your department's procedures and HazMat guidance.

Which of the following is NOT a type of stress that can cause a container to fail? (Page 1258)

A) Chemical

B) Mechanical

C) Biological

D) Thermal

C) Biological

The main types of stress that can cause a hazardous materials container to fail are mechanical, thermal, and chemical.

A) Chemical: Chemical reactions or corrosion can weaken a container.

B) Mechanical: Impact, pressure, or physical force can damage a container.

D) Thermal: Extreme heat or cold can weaken a container or cause pressure changes.

Study tip:

Remember the three types of container stress: Mechanical, Chemical, and Thermal (MCT). Biological stress is not one of the standard categories.

Which of the following is NOT an example of ways containers release their contents due to the input of stress? (Page 1258)

A) Collision

B) Violent rupture

C) Detonation

D) Rapid relief

A) Collision

A collision is an impact or event that causes stress to a container, but it may not be classified as a mechanism by which a container releases its contents in the terminology used on page 1258.

B) Violent rupture: A container can burst under stress and release its contents.

C) Detonation: An explosive event can rupture a container and release its contents.

D) Rapid relief: This may refer to a rapid release of pressure or contents, depending on the textbook's terminology.

Which of the following is the process by which an unstable isotope emits radiation in the form of particles or waves? (Page 1271)

A) Radio isotope

B) Radioactivity

C) Half-life

D) Fission

B) Radioactivity

Radioactivity is the process by which an unstable atomic nucleus releases energy by emitting radiation in the form of particles or electromagnetic waves. This process helps the atom become more stable.

A) Radio isotope: A radioactive isotope is an unstable form of an element that emits radiation.

C) Half-life: The time required for half of the radioactive atoms in a sample to decay.

D) Fission: The process in which an atomic nucleus splits into smaller nuclei, releasing energy.

Study tip:

Remember, radioactivity = the emission of radiation from an unstable atom, while half-life = the time it takes for half of the radioactive material to decay.

Which of the following materials is considered a strong acid? (Page 1268)

A) 99% potassium citrate

B) 97% sulfuric acid

C) 100% acetic acid

D) 30% citric acid

B) 97% sulfuric acid

Sulfuric acid (H₂SO₄) is a strong acid that can cause severe chemical burns and tissue damage. At 97% concentration, it is highly corrosive and extremely dangerous to handle.

A) 99% potassium citrate: A salt, not a strong acid.

C) 100% acetic acid: A weak acid, even though concentrated acetic acid is highly corrosive.

D) 30% citric acid: A weak organic acid.

Study tip:

Remember, sulfuric acid is a strong acid commonly encountered in batteries and industrial settings. Always use appropriate protective equipment when dealing with corrosive materials.

Which of the following time frames is considered a short-term exposure? (Page 1273)

A) Seconds or minutes

B) Months

C) Hours

D) Days

A) Seconds or minutes

A short-term exposure occurs over a brief period, typically seconds or minutes. In hazardous materials incidents, this might happen when a responder briefly inhales toxic vapors or gets a hazardous substance on their skin.

B) Months: Usually associated with long-term or chronic exposure.

C) Hours: Longer than the brief exposure described by the best answer.

D) Days: Generally represents a longer exposure period.

Study tip:

Remember, short-term = seconds or minutes, while chronic = prolonged or repeated exposure over time.

Which of these describes a hazardous material that has been released and physically comes in contact with your skin? (Page 1272)

A) Contaminant

B) Exposure

C) Component

D) Carcinogen

A) Contaminant

A hazardous substance that has been released and is present on a person, object, or surface is considered a contaminant.

B) Exposure: The process of coming into contact with a hazardous material, such as getting a chemical on your skin.

C) Component: One part of a larger substance or system.

D) Carcinogen: A substance or agent capable of causing cancer.

Study Tip

Remember the difference:

Contaminant = the hazardous substance.

Exposure = contact with the hazardous substance.

For example, if a chemical spills onto your hand, the chemical is the contaminant, and your skin contact with it is the exposure.

Which of these describes a lethal dose? (Page 1275)

A) More than 1 kilogram released in a closed building

B) The amount of chemical that kills a given number of test animals

C) Enough to kill an average grown man

D) Five times the normal clinical dose

B) The amount of chemical that kills a given number of test animals

A lethal dose (LD) is the amount of a substance that causes death in a specified proportion of a test population under defined conditions. In toxicology, you may see LD₅₀, which is the dose expected to kill 50% of a test population.

A) More than 1 kilogram released in a closed building: The amount released alone does not determine whether a dose is lethal.

C) Enough to kill an average grown man: Lethality varies depending on the person, substance, route of exposure, and dose.

D) Five times the normal clinical dose: A lethal dose varies by substance and cannot be defined by a fixed multiple of a normal dose.

Study tip:

Remember, LD = lethal dose, and LD₅₀ = the dose that kills 50% of a test population under specified conditions.

Which of these describes concentration? (Page 1269)

A) Focus on an incident

B) The relative amount of a substance in a solvent

C) How many rescuers are present in the hot zone

D) The weight of a chemical present in a container

B) The relative amount of a substance in a solvent

Concentration describes the amount of a substance dissolved in or mixed with another substance (the solvent). In hazardous materials incidents, concentration helps responders understand how much of a chemical is present in a given mixture and how dangerous that mixture may be.

A) Focus on an incident: Refers to attention or priorities, not a chemical property.

C) How many rescuers are present in the hot zone: Describes personnel numbers, not chemical concentration.

D) The weight of a chemical present in a container: Describes the amount of material, but not its relative amount within a mixture.

Study tip:

Remember, concentration = how much of a substance is present in a mixture. Higher concentration can mean greater risk, depending on the substance and the type of exposure.

Which of these describes water solubility? (Page 1267)

A) How quickly 1 gram of a substance disappears in water

B) Whether a substance can be washed off with a water-based cleanser

C) The ability of a substance to dissolve in water

D) How much water another substance can hold

A) How quickly 1 gram of a substance disappears in water

Which of these is the driving force for the creation of toxic products of combustion? (Page 1271)

A) Heat

B) Vapor pressure

C) Wind

D) Concentration

A) Heat

Heat is the driving force behind the creation of toxic products of combustion. When materials burn or decompose under high temperatures, they can release dangerous gases and vapors, such as carbon monoxide and hydrogen cyanide.

B) Vapor pressure: Describes a substance's tendency to vaporize.

C) Wind: Can spread smoke and toxic combustion products but does not drive their formation.

D) Concentration: Describes the amount of a substance present in a given volume; it does not cause combustion products to form.

Study tip:

Remember, heat drives combustion, and combustion can produce toxic gases.

Which type of radiation is capable of producing ions and damaging cells? (Page 1270)

A) Ionizing radiation

B) Non-ionizing radiation

C) Isotope

D) Electromagnetic

A) Ionizing radiation

Ionizing radiation has enough energy to remove electrons from atoms, creating ions. This process can damage cells and DNA, potentially causing burns, radiation sickness, or an increased risk of cancer.

B) Non-ionizing radiation: Does not have enough energy to ionize atoms, although it can still cause harm, such as tissue heating.

C) Isotope: A form of an element with a specific number of neutrons; some isotopes emit radiation.

D) Electromagnetic: Electromagnetic radiation is a broad category that includes both ionizing and non-ionizing radiation.

Study tip:

Remember, ionizing = enough energy to remove electrons and potentially damage cells.

Why is it important to know the state of matter and understand the physical properties of the material that is being released? (Page 1257)

A) To predict the velocity at which the product is likely to escape

B) To determine the severity and potential for harm

C) To predict the amount of product that is likely to escape

D) To predict what the substance will do if it escapes

D) To predict what the substance will do if it escapes

Knowing the state of matter (solid, liquid, or gas) and the material's physical properties helps emergency responders predict how a released hazardous material will behave. For example, they can determine whether it will spread across the ground, vaporize into the air, sink, or rise.

A) To predict the velocity at which the product is likely to escape: This depends more on factors such as pressure and the size of the leak.

B) To determine the severity and potential for harm: Toxicity and exposure risks help determine the potential harm, but physical properties primarily help predict the material's behavior.

C) To predict the amount of product that is likely to escape: This depends on factors such as the size of the release and the container's pressure.

Study tip:

Remember, physical properties help you predict how a hazardous material will behave when released.

You are looking at an SDS sheet and the vapor pressure is listed as 3 atm. How many mm Hg is the vapor pressure? (Page 1263)

A) 3 mm Hg

B) 1 mm Hg

C) 2148 mm Hg

D) 44.1 mm Hg

C) 2148 mm Hg

You arrive at the scene of a motor vehicle accident. Gasoline has been released from one of the vehicles and you inhale the vapor without respiratory protection. Which of the following best describes your exposure? (Page 1273)

A) Short-acting

B) Chronic

C) Insignificant

D) Acute

D) Acute

An acute exposure occurs when a person is exposed to a hazardous substance over a short period of time, often during a single incident. In this case, inhaling gasoline vapors at a motor vehicle accident is an acute exposure.

A) Short-acting: Not the standard term used to classify this type of hazardous-materials exposure.

B) Chronic: Exposure that occurs repeatedly or over a prolonged period of time.

C) Insignificant: You cannot assume the exposure is harmless just because it happened briefly.

Study tip:

Remember acute = short-term exposure and chronic = long-term or repeated exposure. Acute exposure can still cause serious health effects, depending on the substance and the amount inhaled.

You have responded to a scene and find a 55-gallon drum with bulging ends. What physical property is responsible for this? (Page 1263)

A) LEL-UEL

B) Flash point

C) Vapor pressure

D) Vapor density

C) Vapor pressure

Vapor pressure is the pressure exerted by a vapor above its liquid in a closed container. As a liquid evaporates, vapor can build up inside the drum, increasing internal pressure and causing the ends to bulge.

A) LEL-UEL: The lower and upper explosive limits define the concentration range in which a vapor can ignite.

B) Flash point: The lowest temperature at which a liquid gives off enough vapor to ignite under specified test conditions.

D) Vapor density: Describes the density of a vapor compared with air, indicating whether it tends to rise or settle.

Study tip:

Remember, vapor pressure = pressure inside the container. A bulging drum can indicate dangerous internal pressure, so never approach or handle it without appropriate hazardous materials training and direction.