Random Flashcards
What is the purpose of a Photoionization Detector (PID)?
To detect volatile organic compounds (VOCs) and some toxic gases by measuring ionization.
What does BLEVE stand for?
Boiling Liquid Expanding Vapor Explosion.
What are the four main types of railcars used for hazardous materials transport?
- Pressure tank cars
- General service tank cars
- Cryogenic liquid tank cars
- Hopper cars
What is the NFPA 704 marking system commonly called?
The fire diamond.
What is the difference between LEL and UEL?
LEL (Lower Explosive Limit) is the lowest concentration of a gas that can ignite, while UEL (Upper Explosive Limit) is the highest concentration that can ignite.
What is the primary hazard of hydrogen cyanide (HCN)?
It is highly toxic and interferes with the body’s ability to use oxygen.
Which DOT hazard class covers flammable liquids?
Class 3.
What does ‘IDLH’ stand for, and why is it important?
Immediately Dangerous to Life or Health; it indicates the maximum concentration of a substance where escape is possible without severe harm.
What color is the section in the ERG (Emergency Response Guidebook) for initial isolation and protective distances?
Green.
What is the difference between vapor density and specific gravity?
Vapor density refers to gases compared to air (air = 1), while specific gravity refers to liquids compared to water (water = 1).
What does the term ‘permissible exposure limit’ (PEL) mean?
The legal limit for exposure to a substance in the workplace.
What is the purpose of a foam blanket in hazmat response?
To suppress vapors and prevent ignition of flammable liquids.
What is the primary hazard of oxidizers?
They can intensify fires or cause materials to combust.
What are the three primary modes of hazmat transportation?
- Rail
- Road
- Pipeline
What type of railcar has a dome on top and is used for transporting pressurized gases?
Pressure tank car.
What does the acronym SLUDGEM represent in hazmat?
- Salivation
- Lacrimation
- Urination
- Defecation
- Gastrointestinal upset
- Emesis
- Miosis
What are the four routes of entry for hazardous materials?
- Inhalation
- Ingestion
- Absorption
- Injection
What is the purpose of a hazmat decontamination corridor?
To systematically remove contaminants from personnel and equipment.
What type of protective clothing is required for Level A hazmat response?
Fully encapsulating chemical-resistant suit with SCBA.
What is the difference between a solid, liquid, and gas in terms of hazmat behavior?
- Solids generally stay in place
- Liquids can spill and flow
- Gases disperse rapidly
What is the significance of the 2.1, 2.2, and 2.3 DOT classifications?
- 2.1: Flammable gases
- 2.2: Non-flammable gases
- 2.3: Toxic gases
What type of valve is commonly found on pressurized railcars?
Spring-loaded relief valve.
What is the definition of corrosivity?
The ability of a substance to cause damage to materials, skin, or tissue by chemical action.
How is a cryogenic liquid stored and transported?
In insulated containers under very low temperatures to keep it in liquid form.
What is the difference between an acid and a base in hazmat?
Acids have a pH below 7, and bases have a pH above 7.
What does the term ‘specific gravity’ tell you about a liquid?
Whether it will sink or float in water.
What is the main hazard of chlorine gas?
It is a strong oxidizer and highly toxic to respiratory systems.
What is polymerization, and why is it a concern in hazmat?
A chemical reaction that can release heat and pressure, potentially leading to explosions.
What does ‘TLV-STEL’ stand for?
Threshold Limit Value - Short Term Exposure Limit.
Which tool is commonly used to monitor for LEL in a confined space?
Combustible gas indicator.
What does the term ‘boiling point’ indicate?
The temperature at which a liquid turns to vapor.
What is the purpose of grounding and bonding in hazmat operations?
To prevent static electricity buildup and potential ignition.
What is a common symptom of hydrogen sulfide exposure?
Rotten egg smell followed by loss of smell at higher concentrations.
What is the primary hazard of a flammable gas leak in an enclosed space?
Risk of explosion.
What does the term ‘flash point’ refer to?
The lowest temperature at which a liquid gives off enough vapor to ignite.
How does temperature affect vapor pressure?
Higher temperature increases vapor pressure, causing faster evaporation.
What is the role of an Incident Safety Officer during a hazmat incident?
To monitor and ensure the safety of personnel and operations.
What are ‘placards’ and why are they important in hazmat?
Placards are signs on vehicles or containers indicating the type of hazardous material.
What type of chemical is commonly neutralized with baking soda during hazmat cleanup?
Acids.
What is the maximum working pressure of a DOT-105 tank car?
Up to 600 psi.
What is the main hazard associated with cryogenic materials?
Extreme cold can cause frostbite and materials embrittlement.
What does the term ‘autoignition temperature’ mean?
The temperature at which a substance ignites without an external ignition source.
What type of radiation requires heavy shielding, such as lead, for protection?
Gamma radiation.
What is a primary indicator of chemical reactivity in a substance?
The presence of reactive functional groups like peroxides or halogens.
What is the ERG guide number used for a flammable liquid?
128.
What is the purpose of a ‘diking’ strategy in hazmat response?
To contain liquid spills and prevent them from spreading.
What is the major hazard of ammonia gas leaks?
Toxic inhalation and corrosive effects.
What is the difference between a combustible liquid and a flammable liquid?
Combustible liquids have a flash point above 100°F; flammable liquids have a flash point below 100°F.
What does ‘sorption’ mean in hazmat operations?
The process of soaking up or absorbing a spilled material.
What is the primary use of an SCBA in hazmat?
To protect against inhalation of toxic or oxygen-deficient atmospheres.
What is the primary hazard of polyvinyl chloride (PVC) when it burns?
It releases hydrogen chloride gas, which forms hydrochloric acid when combined with moisture.
What is the difference between a Type B and Type A radioactive package?
Type A packages are used for materials with lower levels of radioactivity; Type B packages are designed for highly radioactive materials and can withstand severe accident conditions.
What is the function of a thermal relief valve on a pressure vessel?
To release excess pressure caused by temperature increases and prevent vessel rupture.
How does the persistence of a chemical impact its behavior in a hazmat incident?
Persistent chemicals remain in the environment for extended periods, increasing cleanup difficulty and long-term exposure risks.
What is a ‘chameleon’ sensor, and what is its role in hazmat response?
A wearable colorimetric sensor that changes color when exposed to specific toxic gases, providing real-time detection.
What is the significance of the term ‘pyrophoric’?
A substance that ignites spontaneously when exposed to air.
What are the four subcategories of corrosive materials under the DOT hazard class?
- Acids
- Bases
- Oxidizers
- Water-reactive substances
What are the identifying features of a DOT-112 tank car?
It is used for liquefied gases, has thick insulation, and a protective housing for valves.
What is the difference between acute and chronic exposure?
Acute exposure involves a single, high-dose incident, while chronic exposure occurs over a long time with lower doses.
Why are halogenated hydrocarbons a concern in hazmat incidents?
They can form highly toxic and corrosive byproducts like phosgene gas when burned.
What does the ‘HAZCOM Standard’ require for employers?
To provide Safety Data Sheets (SDS) and ensure workers are trained on hazardous chemicals they may encounter.
What is the significance of a gas with a vapor density greater than 1 in a hazmat incident?
It will settle in low-lying areas, increasing the risk of exposure in confined spaces.
What does the term ‘chemical asphyxiant’ refer to, and give an example?
A substance that interferes with the body’s ability to use oxygen, such as carbon monoxide or hydrogen cyanide.
What is the purpose of a dry break coupling in hazmat transport?
To minimize leaks during loading or unloading of hazardous liquids or gases.
What kind of container is typically used for transporting cryogenic liquids?
A Dewar flask or cryogenic liquid tank.
How does a catalytic bead sensor detect flammable gases?
It oxidizes the gas, producing heat that changes the resistance in the sensor.
What are the two primary hazards associated with ethylene oxide?
- Highly flammable
- Carcinogenic
What does a ‘yellow placard’ indicate in the DOT system?
An oxidizer.
Why is sulfuric acid a concern in a fire?
It can release toxic gases like sulfur dioxide when heated.
What is the significance of the word ‘polymerizing’ in a chemical hazard?
It indicates a substance that can rapidly self-react, generating heat and pressure.
What is the primary difference between a combustible gas indicator (CGI) and a PID?
CGI measures flammable gases relative to LEL; PID detects VOCs and toxic gases.
What is the minimum temperature at which a chemical can sustain combustion called?
Fire point.
What is the role of a water curtain in hazmat operations?
To reduce vapor concentrations and protect exposures from radiant heat.
How can you identify a MC-331 cargo tank?
It has a rounded shape, no insulation, and is designed for pressurized gases like propane.
What is the primary hazard of peroxides in hazmat incidents?
They are highly reactive and can explode when exposed to heat or friction.
What does the term ‘miscibility’ refer to in hazardous materials?
A substance’s ability to mix with water or another liquid.
What is the difference between a primary and secondary containment system?
Primary containment holds the material directly; secondary containment captures spills or leaks.
What is the purpose of the UN four-digit identification number?
To identify specific hazardous materials for transportation and response.
What does ‘PEL-TWA’ mean?
Permissible Exposure Limit - Time Weighted Average; the average concentration over an 8-hour workday.
Why are halons considered dangerous despite being non-flammable?
They deplete oxygen and release toxic gases when exposed to heat.
What are the key features of a cryogenic intermodal tank (IMO Type 7)?
- Designed for cryogenic liquids
- Highly insulated
- Equipped to maintain low temperatures during transport
What does the term ‘threshold shift’ refer to in hazmat incidents involving radiation?
A measurable change in radiation detection readings caused by high exposure levels.
How does particle size affect the dispersion of a hazardous aerosol?
Smaller particles remain airborne longer and travel further, increasing exposure risk.
What is the function of an overpack drum in hazmat?
To contain a leaking or damaged container for safe transport and handling.
Why is mercury considered a unique hazmat risk?
It is a liquid metal that vaporizes at room temperature, creating inhalation hazards.
What is the difference between a toxic inhalation hazard (TIH) and a simple asphyxiant?
TIH gases are chemically harmful to the body, while simple asphyxiants displace oxygen.
What does the acronym CHEMTREC stand for?
Chemical Transportation Emergency Center.
What is a reactive chemical ‘inhibitor’?
A substance added to prevent or slow down unwanted reactions like polymerization.
Why are confined spaces more dangerous in hazmat situations?
They can trap gases, limit oxygen, and restrict escape routes.
What are the effects of over-pressurization in a cryogenic tank?
It can cause violent rupture or venting of supercooled liquid gases.
What is the primary hazard of anhydrous ammonia?
It is highly corrosive and can cause severe respiratory and skin burns.
How does pH impact hazmat decision-making?
Extreme pH levels indicate corrosive materials, influencing PPE and containment strategies.
What is the purpose of diking in hazmat spill control?
To prevent the spread of liquids by creating barriers.
How does temperature affect the solubility of gases in water?
Higher temperatures reduce gas solubility, potentially releasing dissolved hazardous gases.
What is the hazard of a material classified as ‘spontaneously combustible’?
It can ignite without an external heat source.
What kind of radiation can be shielded by heavy clothing or a plastic sheet?
Beta radiation.
What is the primary use of sodium bicarbonate in hazmat response?
To neutralize acids during spills or cleanup.
What are the main hazards of hydrogen fluoride?
It is highly corrosive, toxic, and can penetrate skin to attack underlying tissues and bones.
What is the purpose of a vapor dispersion tactic?
To reduce gas concentration by using water spray or fans to disperse vapors.
How does wind direction affect hazmat incident management?
It determines the spread of hazardous gases or vapors, guiding evacuation and containment zones.
What does the blue section in the NFPA 704 fire diamond represent?
Health hazard.
What is the primary purpose of the ERG (Emergency Response Guidebook)?
To provide initial response guidance for hazardous material incidents.
What does LEL stand for?
Lower Explosive Limit.
What does the color yellow signify in a DOT placard?
Oxidizers.
What are the four routes of entry for hazardous materials?
- Inhalation
- Ingestion
- Absorption
- Injection
What is the difference between a gas and vapor in hazmat terms?
A gas is naturally in a gaseous state, while a vapor is the gaseous form of a substance that is normally a liquid or solid at room temperature.
What DOT hazard class covers flammable gases?
Class 2.1.
What is the purpose of a hazmat decontamination corridor?
To remove contaminants from personnel and equipment.
What does ‘IDLH’ stand for?
Immediately Dangerous to Life or Health.
What color section of the ERG contains initial isolation distances?
Green.
What does the term ‘specific gravity’ indicate?
Whether a liquid will sink or float in water.
What kind of chemical reaction releases heat?
Exothermic reaction.
What type of valve is found on pressure tank cars?
Spring-loaded relief valve.
What does ‘miscible’ mean?
Two liquids can mix completely.
What is the purpose of a vapor suppression tactic?
To reduce the amount of hazardous vapors released into the air.
What is the definition of corrosivity?
A material’s ability to damage or destroy other materials, including living tissue.
What is a common symptom of carbon monoxide poisoning?
Headache and dizziness.
What is the main hazard of chlorine gas?
It is highly toxic to the respiratory system.
What does ‘flash point’ mean?
The lowest temperature at which a liquid gives off enough vapor to ignite.
What does vapor density greater than 1 indicate?
The gas will settle in low-lying areas.
What is the primary hazard of cryogenic liquids?
Extreme cold that can cause frostbite and embrittlement.
What is the pH range of a neutral substance?
7.
What does ‘PEL’ stand for?
Permissible Exposure Limit.
What is the term for a chemical’s ability to react violently with water?
Water-reactive.
What is the purpose of grounding and bonding during hazmat operations?
To prevent static electricity and potential ignition.
What does the white section of the NFPA 704 diamond indicate?
Special hazards (e.g., oxidizers or water reactivity).
What type of radiation requires only paper or clothing for shielding?
Alpha radiation.
What is the main hazard of a BLEVE (Boiling Liquid Expanding Vapor Explosion)?
Thermal and blast effects from a pressurized liquid turning into vapor.
What is the main hazard of hydrogen sulfide?
Toxicity and flammability.
What is the purpose of a catalytic bead sensor in hazmat monitoring?
To detect flammable gases by measuring heat from oxidation.
What is a ‘Class 9’ material in the DOT system?
Miscellaneous hazardous material.
What is the purpose of a thermal relief valve on a pressure vessel?
To relieve excess pressure caused by temperature increases.
What does ‘autoignition temperature’ mean?
The temperature at which a substance ignites without an external ignition source.
What type of railcar is used to transport pressurized gases?
DOT-112 or DOT-105 tank car.
Why are oxidizers dangerous?
They can intensify combustion.
What is the primary hazard of ammonia?
It is corrosive and can cause respiratory injury.
How does temperature affect vapor pressure?
Higher temperature increases vapor pressure.
What does a ‘flammable range’ describe?
The concentration range between LEL and UEL where a substance can ignite.
What is a polymerization reaction?
A chemical reaction that produces heat and pressure by forming larger molecules.
What is the purpose of a foam blanket during hazmat response?
To suppress vapors and prevent ignition.
What does ‘permissible dose’ mean in radiation terms?
The maximum radiation dose allowed for a worker in a given time.
What is the significance of vapor pressure in a hazmat scenario?
It determines how readily a liquid turns into vapor.
What are the two primary hazards of hydrogen cyanide?
- Flammability
- Toxicity
What kind of placard is used for radioactive materials?
Class 7 placard.
What does ‘sorption’ mean in hazmat terms?
The process of absorbing or adsorbing a hazardous material.
What does the acronym ‘SCBA’ stand for?
Self-Contained Breathing Apparatus.
Why are halogens (like chlorine) a concern in hazmat?
They are highly reactive and can form toxic byproducts.
What is a ‘LEPC’ in hazmat response?
Local Emergency Planning Committee.
What is the primary hazard of methyl ethyl ketone (MEK)?
It is highly flammable.
What is ‘chemical incompatibility’?
When two substances react violently upon contact.
What type of railcar is used for transporting cryogenic liquids?
Cryogenic liquid tank car (e.g., DOT-113).
What is the TLV-Ceiling for hydrogen sulfide?
20 ppm.
What is the purpose of a dry break coupling in hazmat transport?
To minimize spills during loading or unloading.
Why is hydrogen fluoride considered highly hazardous?
It can penetrate skin and damage bones.
What is the main hazard of ethylene oxide?
It is flammable and carcinogenic.
How does particle size affect the spread of hazardous aerosols?
Smaller particles travel further and remain airborne longer.
What is the minimum protective distance for a large chlorine release, according to the ERG?
1.6 miles for an initial isolation zone.
What is the difference between an MC-306 and an MC-307 cargo tank?
MC-306 is for flammable liquids, while MC-307 is for toxic or corrosive liquids.
What is the significance of a material’s ionization potential?
It determines whether it can be detected by a PID.
Why are halogenated hydrocarbons dangerous during combustion?
They release toxic gases like phosgene and hydrogen chloride.
What does the term ‘threshold shift’ refer to in radiation monitoring?
Changes in detection levels after exposure to high radiation doses.
Why is polymerization a major concern in hazmat incidents?
It can cause runaway reactions with heat and pressure buildup.
What does the acronym LC50 mean?
Lethal Concentration for 50% of test subjects.
How does atmospheric stability affect hazardous gas plumes?
Stable atmospheres keep plumes closer to the ground.
What type of hazardous material is transported in a Type B package?
High-level radioactive materials.
What kind of radiation can penetrate concrete?
Gamma radiation.
What is the primary hazard of sulfur dioxide?
It is highly toxic and can cause respiratory damage.
What is the purpose of the green band on a gas cylinder?
It indicates an oxidizing gas.
How does relative humidity impact hazmat incidents involving gases?
High humidity can slow gas dispersion by reducing vapor pressure.
What is the main hazard associated with nitromethane?
It is both highly flammable and explosive.
What is the boiling point of liquid oxygen?
-183°C (-297°F).
What is the purpose of an overpack drum?
To safely contain leaking or damaged containers.
What is the role of the CHEMTREC hotline?
To provide emergency response information for hazmat incidents.
What is the main hazard of hydrazine?
It is highly toxic and a strong reducing agent.
How do temperature inversions affect hazardous materials releases?
They trap gases near the ground, increasing exposure risks.
What is the ionization potential of benzene, and why does it matter?
9.24 eV; it determines detectability using PIDs with UV lamps.
What is the effect of strong acids on reactive metals like sodium?
They produce flammable hydrogen gas.
How do you calculate the vapor pressure of a substance at a specific temperature?
Use the Antoine Equation, specific to the substance.
What is the significance of the Reid Vapor Pressure (RVP) of gasoline?
It predicts the potential for vapor generation and flammability.
What DOT tank specification is used for sulfuric acid?
DOT-412.
Why is ethylene glycol monomethyl ether considered highly hazardous?
It can cause reproductive toxicity and is absorbed through the skin.
What is the TLV-STEL for ammonia?
35 ppm.
How does a PID detect gases, and what limits its application?
It ionizes gases using UV light; it cannot detect substances with high ionization potentials.
What is the purpose of a rupture disc on a cryogenic tank?
To relieve excess pressure before the tank fails catastrophically.
How does a Dewar flask prevent heat transfer?
By using vacuum insulation.
What is the significance of ‘critical temperature’ in cryogenic storage?
The temperature above which a gas cannot be liquefied, regardless of pressure.
How do you calculate the isolation distance for an ammonia release?
Refer to the ERG and adjust for weather and topography.
What does ‘WRT’ mean on a hazmat label?
Water Reactive.
What is the primary hazard of methyl isocyanate (MIC)?
It is highly toxic and was responsible for the Bhopal disaster.
Why do some chemicals have a flash point below room temperature?
Their vapor pressure is high enough for flammable vapors to form.
How do you determine the neutralization agent for a hazardous spill?
Refer to the chemical’s SDS for compatibility.
What is the difference between dose rate and cumulative dose in radiation?
Dose rate measures exposure over time; cumulative dose is the total absorbed.
What is the hazard of diisocyanates in hazmat incidents?
They are toxic sensitizers and can cause severe respiratory issues.
What is the purpose of a containment boom in hazmat spills?
To limit the spread of liquid spills in water.
How does wind speed impact dispersion modeling in hazmat?
Higher wind speeds dilute gases faster but spread them over larger areas.
Why is nitrobenzene classified as a Class 6 material?
It is highly toxic but not reactive or flammable.
How is ethyl methyl ketone peroxide (MEKP) stabilized for transport?
By adding inhibitors to prevent spontaneous decomposition.
What is the purpose of a flame arrester in hazmat storage?
To prevent flames from entering a container and igniting vapors.
Why is hydrogen classified as both flammable and explosive?
Its LEL and UEL ranges are extremely wide.
How do you determine if a material is considered hazardous waste?
Evaluate it against EPA criteria for ignitability, corrosivity, reactivity, and toxicity.
What is the “Tier II Chemical Inventory Report,” and why is it critical for hazmat teams?
It is a required report under the EPCRA (Emergency Planning and Community Right-to-Know Act), detailing the storage of hazardous chemicals above threshold amounts. It helps hazmat teams pre-plan and identify risks at facilities in their jurisdiction.
How does atmospheric stability (e.g., Pasquill Stability Classes) affect the dispersion of hazardous materials?
Atmospheric stability measures the turbulence of the air. Stable atmospheres (Class F) trap hazardous gases near the ground, while unstable atmospheres (Class A) promote rapid dispersion, reducing localized concentration.
What is the “Zoning Concept” in hazmat response, and how do hot, warm, and cold zones differ?
The zoning concept establishes areas of safety and contamination:
• Hot Zone: Immediate danger; direct contamination risk.
• Warm Zone: Decontamination and transition area.
• Cold Zone: Safe area for command and support functions.
How does a PID (Photoionization Detector) detect substances, and what are its limitations?
A PID uses UV light to ionize chemicals in the air. It measures ionized particles to detect VOCs and some toxic gases. Limitations include an inability to detect chemicals with ionization potentials higher than the lamp energy and non-specific readings.
What is the difference between “high-boiling-point chemicals” and “low-boiling-point chemicals” in terms of hazmat risk?
Low-boiling-point chemicals (e.g., propane) vaporize easily, increasing fire/explosion risks. High-boiling-point chemicals (e.g., diesel) are less volatile but may produce harmful vapors when heated.
How does the “Knudsen Diffusion Effect” influence gas movement in hazmat incidents?
It describes how gases behave in confined spaces (e.g., pores, cracks) where molecular collisions dominate over bulk flow, affecting how hazardous gases spread in limited environments.
What is the significance of “boiling liquid expanding vapor explosion” (BLEVE) predictions in hazmat pre-planning?
Understanding BLEVE risks helps identify tanks containing pressurized, flammable liquids that may fail catastrophically due to rapid heat exposure, allowing for safer standoff distances and mitigation.
Explain how the “vapor pressure curve” of a chemical aids in predicting its behavior in different temperatures.
The vapor pressure curve shows how a liquid’s pressure increases with temperature, helping responders predict evaporation rates, vapor concentration, and the likelihood of exceeding LEL/UEL in various scenarios.
How does “adsorption capacity” influence the selection of activated carbon filters for hazmat incidents?
Adsorption capacity determines how effectively activated carbon removes specific chemicals from air or water. The choice depends on the chemical’s molecular weight, polarity, and concentration.
What is “hazardous materials plume modeling,” and how is it applied during hazmat responses?
Plume modeling predicts the spread of airborne hazardous substances based on factors like wind speed, topography, temperature, and atmospheric stability. It helps establish isolation zones and evacuation areas.
