Chemical And Physcial Properties Flashcards
What is the significance of a chemical’s name and synonyms in hazmat?
A chemical’s name and synonyms help identify the substance correctly in databases or emergency guides, preventing confusion during a response.
What is a CAS number, and why is it important?
A CAS (Chemical Abstracts Service) number is a unique identifier for a chemical, ensuring accurate identification regardless of naming differences.
What is the OSHA PEL?
The OSHA Permissible Exposure Limit (PEL) is the maximum airborne concentration of a substance workers can be exposed to over an 8-hour workday.
What is the NIOSH REL?
Measurement timeframe names?
The NIOSH Recommended Exposure Limit (REL) is a guideline for the maximum safe exposure level to a substance, often more stringent than OSHA PEL.
Measurement Time Frames:
• TWA (Time-Weighted Average): Average exposure over an 8- or 10-hour workday.
• STEL (Short-Term Exposure Limit): Maximum exposure limit over a short-term period, typically 15 minutes.
• Ceiling (C): The concentration that should never be exceeded, even momentarily.
What is the ACGIH TLV?
The Threshold Limit Value (TLV) set by the ACGIH defines safe exposure limits for most workers over an 8-hour workday.
What is the significance of a chemical’s physical state in hazmat?
The physical state (solid, liquid, gas) determines how the chemical behaves and spreads, affecting its containment and response measures.
Why are appearance and odor important for identifying chemicals?
Appearance and odor help visually or physically identify chemicals, but odor should not be relied on due to desensitization or odorless hazards.
What is the boiling point, and why is it significant in hazmat?
The boiling point is the temperature at which a liquid becomes vapor, indicating its volatility.
What is the freezing/melting point?
The temperature where a substance transitions between solid and liquid states.
What is vapor pressure, and why is it important in hazmat?
Vapor pressure measures a liquid’s tendency to evaporate; higher vapor pressure indicates greater volatility.
What is vapor density, and how does it affect hazmat response?
Vapor density compares the weight of a vapor to air (air = 1). Vapors heavier than air sink, affecting ventilation strategies.
What is specific gravity, and why is it significant?
Specific gravity compares a substance’s density to water (water = 1). Substances with a specific gravity > 1 sink in water.
What is molecular weight, and why is it important in hazmat?
Molecular weight is the weight of a molecule and helps in understanding gas behavior.
What is a flashpoint, and why is it significant?
The flashpoint is the minimum temperature at which a liquid’s vapors ignite.
What does solubility in water indicate?
Solubility shows how well a chemical dissolves in water, affecting cleanup and dispersion.
Jfrd uses 10 as the over under for soluble or not
Why is stability important in hazmat?
Stability indicates whether a substance decomposes or reacts under normal conditions, impacting storage and transport safety.
What are chemical incompatibilities?
Incompatibilities are substances or conditions that cause dangerous reactions.
What are the flammable limits, and why are they important?
Flammable limits define the concentration range in air where a substance can ignite.
What is autoignition temperature?
The autoignition temperature is the minimum temperature at which a substance ignites without an external spark.
What are target organs, and why are they important?
Target organs are the parts of the body most affected by exposure to a chemical.
What role do symptoms play in hazmat?
Symptoms help identify exposure to a substance.
What is oxidation potential?
Oxidation potential measures a substance’s ability to gain electrons.
What does persistence mean in hazmat?
Persistence describes how long a chemical remains hazardous in the environment.
What does pH measure, and why is it important in hazmat?
pH stands for “potential of hydrogen” or “power of hydrogen.” It measures the concentration of hydrogen ions (H⁺) in a solution, indicating its acidity or alkalinity.
pH measures acidity or alkalinity, with 7 being neutral. Over 7 is alkaline under 7 is acidic. Each number is to the power of 10 from the next
What is polymerization, and why is it a hazard?
Polymerization is when small molecules combine to form larger ones, which can release heat and cause explosions if uncontrolled.
What is sublimation?
Sublimation is the process where a solid changes directly into a gas.
Why is a product’s temperature important in hazmat?
The product’s temperature affects its state, pressure, and reactivity.
What is latent heat, and why is it important in hazmat?
Latent heat is the energy required for a substance to change phase without a temperature change.
What is the vapor pressure curve, and why is it significant?
The vapor pressure curve shows how vapor pressure changes with temperature.
What is the heat of combustion?
The heat of combustion is the amount of heat released when a substance burns completely.
What is BLEVE, and how does it occur?
A BLEVE occurs when a pressurized liquid overheats and vaporizes explosively.
What is the partition coefficient, and why is it significant?
Log Kow measures a chemical’s distribution between water and octanol, indicating its potential to bioaccumulate.
Octanol represents organic matter
Water represents aqueous phase
Determines wether a substance is more likely to dissolve in water or oils
What is Henry’s Law constant, and why is it useful?
Henry’s Law constant describes how much a gas dissolves in a liquid under pressure.
Higher constant means gas escapes water easily
Lower stays dissolved
Henry’s Law Constant is typically measured in atm·m³/mol (pressure multiplied by volume per amount of substance) or Pa·m³/mol.
What is deposition in hazmat?
Deposition is the process where a gas changes directly into a solid.
What is TLV-STEL, and why is it important?
Threshold limit value Short-Term Exposure Limit (STEL) is the maximum concentration workers can safely endure for 15 minutes.without symptoms. Can occur 4 times per day with 60 minutes in between
What is molecular polarity, and how does it affect hazmat behavior?
Whether the molecules charge the chemical positive or negative or cancel out, can cancel out due to shape or charge.
Polarity determines how a chemical interacts with water or organic solvents.
What is the difference between adsorption and absorption?
Adsorption is when a substance adheres to a surface, while absorption is when it penetrates into a material.
What is ionization energy, and why is it relevant?
Ionization energy is the energy required to remove an electron from an atom or molecule.
What is LC50, and why is it critical?
LC50 is the concentration of a substance in air that kills 50% of exposed test subjects.
What is LD50, and why is it significant?
LD50 is the dose of a substance that kills 50% of test subjects, typically via ingestion or skin exposure.
What are reaction kinetics, and how do they apply to hazmat?
Reaction kinetics study the rate of chemical reactions. How and why a reaction occurs and at what speed
Helps understand stability and predicts outcomes
What is permeation rate, and why is it important for PPE?
Permeation rate measures how quickly a chemical passes through a material.
What is the difference between exothermic and endothermic reactions?
Exothermic reactions release heat, while endothermic reactions absorb heat.
What is a toxicity threshold, and why is it critical?
The lowest concentration of a substance that starts causing toxic effects
It’s a general term for when harm begins
________ can accelerate corrosion or decomposition in reactive chemicals.
Can affect vapor spread and production
Can affect some water reactive chemicals
Humidity
What is chelation, and why is it important?
Chelation refers to the ability of a substance to bind metals, making toxic metals less available in the body.
Used to treat lead or mercury poisoning
What is vaporization rate, and why is it relevant?
Vaporization rate measures how quickly a liquid converts to vapor.
Differs from VP
more of a measurement of speed dictated by outside factors
What is surface tension, and how does it impact hazmat spills?
Surface tension determines how easily a liquid can stretch and stay bonded.
Molecules exp an imbalance and pull inward
Influences spread of material, containment, and reaction with surfaces
What is ionization potential, and why is it critical in hazmat?
Ionization potential measures how easily an atom or molecule becomes ionized.
More specifically how much energy is required to remove an electron, turning it into an ion
PID meters can only see less than the bulb they use
Low IP are more reactive
What is corrosion rate, and how does it affect hazmat storage?
Corrosion Rate: How quickly a material (like metal) is worn down or destroyed by chemical reactions, often with acids, bases, or moisture.
Impact on Hazmat Storage:
1. Container Integrity: High corrosion rates can weaken containers, causing leaks or failures.
2. Chemical Compatibility: Corrosive chemicals must be stored in compatible materials (e.g., plastic instead of metal) to prevent damage.
3. Safety: Faster corrosion increases the risk of hazardous spills or structural failures over time.
Simply, it determines how safe and durable storage containers are for hazardous materials.
ACGIH
The ACGIH stands for the American Conference of Governmental Industrial Hygienists, an organization that provides guidelines and recommendations for occupational health and safety
What is the boiling point of water?
100°C (212°F)
Density formula?
Mass ÷ Volume
State of matter with fixed volume and shape?
Solid
State of matter with no fixed shape but fixed volume?
Liquid
What property measures resistance to flow?
Viscosity
Does a physical change alter chemical composition?
No
Does a chemical change produce new substances?
Yes
Rusting of iron is an Example of a ______?
chemical change
Melting point of ice?
0°C (32°F)
What property describes the ability to burn?
Flammability
What is the pH of a neutral substance?
7
What happens to density as temperature increases?
Decreases
What property describes shine or reflectiveness?
Luster
What is solubility?
Ability to dissolve in a solvent
What property measures heat transfer resistance?
Thermal conductivity
What property describes magnetic attraction?
Magnetism
What type of change is evaporation?
Physical
_______ refers to the tendency of a substance to undergo a chemical reaction, either by itself or with other substances, and the speed or extent of that reaction.
Reactivity
What is the ability to stretch into a wire called?
Ductility
What property measures hardness or resistance to scratching?
Hardness
What is the boiling point of water?
100°C (212°F)
Density formula?
Mass ÷ Volume
State of matter with fixed volume and shape?
Solid
State of matter with no fixed shape but fixed volume?
Liquid
What property measures resistance to flow?
Viscosity
Does a physical change alter chemical composition?
No
Does a chemical change produce new substances?
Yes
Example of a chemical change?
Rusting of iron
Melting point of ice?
0°C (32°F)
What property describes the ability to burn?
Flammability
What is the pH of a neutral substance?
7
What happens to density as temperature increases?
Decreases
What property describes shine or reflectiveness?
Luster
What is solubility?
Ability to dissolve in a solvent
What property measures heat transfer resistance?
Thermal conductivity
What property describes magnetic attraction?
Magnetism
What type of change is evaporation?
Physical
What is reactivity?
Ability to chemically combine
What is the ability to stretch into a wire called?
Ductility
What property measures hardness or resistance to scratching?
Hardness
Lowest vapor concentration to ignite?
LEL
LEL stands for Lower Explosive Limit, indicating the minimum concentration of vapor in air that can ignite.
Maximum vapor concentration to ignite?
UEL
UEL stands for Upper Explosive Limit, indicating the maximum concentration of vapor in air that can ignite.
Temperature at which a liquid becomes a gas?
Boiling Point
The boiling point is the temperature at which a liquid’s vapor pressure equals the external pressure surrounding the liquid.
Temperature at which a liquid becomes solid?
Freezing Point
The freezing point is the temperature at which a liquid turns into a solid.
Lowest temperature a liquid can ignite?
Flash Point
The flash point is the lowest temperature at which vapors of a material will ignite when given an ignition source.
Temperature at which a substance ignites on its own?
Autoignition Temperature
This is the temperature at which a substance will ignite without an external ignition source.
Density compared to water?
Specific Gravity
Specific gravity is a dimensionless quantity that compares the density of a substance to the density of water.
Pressure exerted by a vapor above its liquid?
Vapor Pressure
Vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid at a given temperature.
Density of vapor compared to air?
Vapor Density
Vapor density is a measure of the density of a vapor compared to air, which has a density of 1.
Extent to which a substance dissolves in water?
Solubility
Solubility refers to the ability of a substance to dissolve in a solvent, typically water.
Measure of acidity or alkalinity?
pH
pH is a scale used to specify the acidity or basicity of an aqueous solution.
Sum of atomic weights in a molecule?
Molecular Weight
Molecular weight is the total weight of all atoms in a molecule, expressed in atomic mass units (amu).
Lowest concentration detectable by smell?
Odor Threshold
The odor threshold is the lowest concentration of a substance that can be detected by the sense of smell.
Dangerous concentration for life or escape?
IDLH
IDLH stands for Immediately Dangerous to Life or Health, referring to concentrations that pose an immediate threat.
OSHA’s maximum allowed exposure level?
PEL
PEL stands for Permissible Exposure Limit, which is the maximum concentration of a substance allowed in the workplace.
Concentration recommended by NIOSH?
REL
REL stands for Recommended Exposure Limit, suggesting safe exposure levels by the National Institute for Occupational Safety and Health.
Safe exposure limit set by ACGIH?
TLV
TLV stands for Threshold Limit Value, used by the American Conference of Governmental and Industrial Hygienists to indicate safe exposure levels.
Airborne concentration killing 50% of test subjects?
LC50
LC50 is the lethal concentration for 50% of the test population, often used in toxicity studies.
Dose killing 50% of test subjects?
LD50
LD50 is the lethal dose for 50% of the test population, a standard measure of acute toxicity.
Ability of a substance to catch fire?
Flammability
Flammability indicates how easily a substance can ignite and sustain combustion.
Tendency of a substance to react chemically?
Reactivity
Reactivity refers to how readily a substance undergoes chemical reactions with other substances.
______ refers to the ability of a substance to cause damage to materials, living tissues, or containers through a chemical reaction.
Corrosivity
Corrosivity describes the capability of a substance to cause destruction of living tissue or severe corrosion of materials.
Materials that react dangerously with a substance?
Incompatibilities
Incompatibilities refer to substances that can react dangerously when mixed or in proximity to each other.
Ability of a substance to cause cancer?
Carcinogenicity
Carcinogenicity indicates a substance’s potential to cause cancer in living tissues.
Ability to cause developmental malformations?
Teratogenicity
Teratogenicity refers to the ability of a substance to cause birth defects or developmental abnormalities.
Ability to cause genetic mutations?
Mutagenicity
Mutagenicity is the capacity of a substance to induce changes in the DNA of organisms.
Pathways chemicals enter the body?
Routes of Exposure
Routes of exposure include inhalation, ingestion, and dermal contact, through which chemicals can enter the body.
Organs most affected by exposure?
Target Organs
Target organs are specific organs that are particularly vulnerable to the effects of toxic substances.
Substance causing or intensifying combustion?
Oxidizer
An oxidizer is a substance that can cause or enhance the combustion of other materials.
Degree to which a chemical can harm organisms?
Toxicity
Toxicity is a measure of the harmful effects of a substance on living organisms.
Indicates significant skin absorption?
Skin Notation
Skin notation is an indication that a substance can be absorbed through the skin in significant amounts.
Solubility ratio between octanol and water?
Partition Coefficient (Log P)
The partition coefficient provides insight into the hydrophobicity or lipophilicity of a substance.
Temperature to sustain combustion?
Fire Point
The fire point is the minimum temperature at which a substance can sustain combustion without an external ignition source.
What is the Flash Point for Flammable Liquids?
< 100°F (37.8°C)
Flash point indicates the lowest temperature at which vapors can ignite.
What is the Flash Point for Combustible Liquids?
≥ 100°F (37.8°C)
This classification helps in assessing fire hazards.
What is the Vapor Pressure of Volatile Substances?
> 10 mmHg at 20°C
High vapor pressure indicates a substance readily evaporates.
What is the Specific Gravity of Substances That Sink in Water?
> 1
Specific gravity is a measure of density relative to water.
What is the Specific Gravity of Substances That Float on Water?
< 1
This property is crucial for understanding buoyancy.
What is the Boiling Point for Dangerous Volatile Liquids?
< 100°F (37.8°C)
Lower boiling points can indicate higher volatility.
What is the Autoignition Temperature for Most Combustible Gases?
500–1000°F (260–538°C)
Autoignition temperature is the minimum temperature at which a substance will ignite without an external source.
What is the Lower Explosive Limit (LEL) for Methane?
5%
LEL indicates the minimum concentration of gas in air that can ignite.
What is the Upper Explosive Limit (UEL) for Methane?
15%
UEL indicates the maximum concentration of gas in air that can ignite.
What is the Oxygen Level Considered Deficient?
< 19.5%
Oxygen levels below this threshold can pose health risks.
What is the Oxygen Level Considered Enriched?
> 23.5%
Enriched oxygen environments can increase fire hazards.
What is the IDLH for Carbon Monoxide?
1200 ppm
IDLH stands for Immediately Dangerous to Life or Health.
What is the PEL for Carbon Monoxide?
50 ppm
PEL stands for Permissible Exposure Limit.
What is the REL for Carbon Monoxide?
35 ppm
REL stands for Recommended Exposure Limit.
What is the IDLH for Hydrogen Cyanide (HCN)?
50 ppm
HCN is a highly toxic substance, and its IDLH is critical for safety measures.
What is the PEL for Hydrogen Cyanide?
10 ppm
Exposure limits are set to protect workers from acute and chronic health effects.
What is the Vapor Density of Substances Heavier Than Air?
> 1
Heavier substances can accumulate in low-lying areas, posing risks.
What is the Vapor Density of Substances Lighter Than Air?
< 1
Lighter substances tend to disperse into the atmosphere more readily.
What is the LEL for Gasoline Vapors?
1.4%
Gasoline vapors are highly flammable and require careful handling.
What is the UEL for Gasoline Vapors?
7.6%
Understanding these limits is essential for safety in storage and use.
What is the Boiling Point of Acetone?
56°C (133°F)
Acetone is a common solvent with specific boiling characteristics.
What is the Flash Point of Acetone?
-4°F (-20°C)
Acetone is highly flammable, requiring strict safety measures.
What is the IDLH for Hydrogen Sulfide (H₂S)?
100 ppm
H₂S is a toxic gas, and its IDLH is crucial for worker safety.
What is the PEL for Hydrogen Sulfide?
20 ppm
Exposure regulations help prevent health issues from hydrogen sulfide.
What is the REL for Hydrogen Sulfide (15-min ceiling)?
10 ppm
Short-term exposure limits are essential for acute risk management.
The pH scale is _______ and represents the power of 10 difference in hydrogen ion (H⁺) concentration between values. This means each step on the pH scale corresponds to a tenfold (10x) change in H⁺ concentration.
logarithmic
pH 1 is _____ times more acidic (in terms of H⁺ concentration) than a solution at pH 14.
10 trillion
