Properties and Effects Notes
Properties and Effects
Knowledge Objectives
- Describe states of matter and their physical and chemical changes.
- Understand the ways containers can breach and release contents.
- Discuss the critical characteristics of flammable liquids.
- Understand how to determine the concentration of a released hazardous material.
- Describe ionizing and nonionizing radiation.
- Describe toxic products of combustion.
- Understand the concepts of hazard, exposure, and contamination.
- Describe how hazardous material exposure can lead to chronic and/or acute health effects.
Introduction
- Chemical and physical properties:
- Vapor density
- Flammability
- Corrosivity
- Water reactivity
- Information needed to take basic actions:
- Observations
- SOPs
- References
- Interpretation of clues
- Information provided by labels:
- Name
- Ingredients
- Hazard statement
- Information provided by SDS:
- SDS can be obtained from site facility representatives, Internet, or those responsible for shipping the hazardous materials.
- Information can include supplier identifier and emergency telephone number, hazard identification, and composition/information on ingredients.
- Phone calls to resources:
- CHEMTREC, CANUTEC, SETIQ
- Availability, contacts, information
Physical and Chemical Changes
- States of matter:
- Solid, liquid, or gas/vapor
- Vital information needed to help predict what the substance will do if it escapes
- Container failure:
- The how and why of breaches
- Types of stress:
- Thermal
- Chemical
- Mechanical
- Potential for exposure:
- Duration:
- Short-term
- Medium-term
- Long-term
- Develop a plan.
- Form a hypothesis.
- Establish incident objectives.
- Create an action plan.
- What is leaking? What are the chemical and physical properties of the material?
- Affect of environmental factors on states of matter:
- Water, propane
- Expansion ratio
- BLEVE (boiling liquid/expanding vapor explosion)
- Contributing circumstances
- Responders should take great care when handling incidents involving compressed liquefied gases.
- Chemical reactivity
- Chemical reaction
- Chemical change verses physical change
- Polymers
Critical Characteristics of Flammable Liquids
- Fire potential of a flammable liquid:
- Flashpoint
- Ignition temperature
- Flammable range
- Relationships of flammable liquids:
- Gaseous or vapor state
- Solids and liquids
- Vapor production
- Flash point
- Ignition sources
- Flash fire
- Gasoline and diesel fuel
- Fire point
- Lowest temperature at which sustained combustion of the vapor will occur
- Ignition temperature
- Relationship between temperature and vapor production
- Lowest temperature
- Liquid fuel
- Cooking oil
- Flammable range
- Flammable range
- Gasoline
- LEL and UEL
- Carburation
- Fuel rich/Fuel lean
Vapor Pressure
- Definition
- Headspace
- Vapor measurement
- Vapor containment and pressure
- Equilibrium
- Temperature influence
- Low flash points
- Units of measurement
- Reference sources and valid point of reference
- Conversion factors
- Frame of reference
- Comparisons
- Behavior of substances such as water, standard 40- weight motor oil, and isopropyl alcohol
Boiling Point
- The temperature at which a liquid will continually give off vapors in sustained amounts
- If held at that temperature long enough, it will turn completely into a gas.
- Danger of low boiling points
Vapor Density
- Weight comparison
- SDS vapor density
- Expressed as number
- Gases with density value less than 1 will rise:
- Acetylene
- Natural gas
- Hydrogen
- Gases with density value greater than 1 will sink:
- Mnemonic 4H MEDIC ANNA
Specific Gravity
- Weight comparison
- Specific gravity of water
- Materials that float on or sink in water
- Applying water
- Reaction worse than problem
- Chemical reactivity or incompatibility
- Contaminated runoff
- Unwanted increase in the surface area
Water Solubility
- Ability of a substance to dissolve in water
- Solvent with potential for violent reaction
- Chemical emergencies
- Fog streams
- Heavier-than-water liquids
- Dilution
Corrosivity (pH)
- Damage on contact
- Destruction or irreversible damage to living tissue at the site of contact
- Corrosive chemicals are used in:
- General industry
- Semiconductor manufacturing
- Biotechnology
- pH is a measure of the presence of dissolved hydrogen ions.
- pH scale goes from 1 to 14.
- Acids
- pH less than 7
- More hydrogen ions in solution
- Examples:
- Sulfuric acid
- Hydrochloric acid
- Phosphoric acid
- Nitric acid
- Acetic (vinegar) acids
- Bases
- pH greater than 7
- More hydroxide ions in solution
- Examples:
- Sodium hydroxide
- Potassium hydroxide
- Sodium carbonate
- Ammonium hydroxide
- Neutral substances
- pH of 7
- Hydrogen ions equal to hydroxide ions in solution
- Do not harm human tissue
- Strong corrosive substances
- pH less than 2.5 or greater than 12.5
- Aggressive reactions
- Weak corrosive substances
- pH greater than 2.5 or less than 12.5
- pH testing
- Specialized pH test paper
- SDS
- Specialized hazardous materials response team
- Incidents involving corrosives at the operations level
- Not as straightforward and materials are complicated.
- Tactics employed could be outside of the scope of responsibilities.
Determining the Concentration of a Released Hazardous Material
- Solution
- Solute dissolved in a solvent such as salt water
- Concentration
- Amount of solute in solvent or the ratio of solute
- Concentrated versus dilute
- Non-liquid substances
- Gas release
- Concentrations of gases often expressed as percentages
- Airborne concentration of natural gas
- Incidents involving corrosives
- Concentration of the released substance
- Concentration and strength of solution
- Strength of corrosive refers to degree of ionization.
- Strong corrosives react more vigorously with incompatible materials.
- Strong corrosives are more aggressive with metallic objects.
Ionizing and Nonionizing Radiation
- Radiation
- Transmission of energy from sources such as the sun, soil, airplanes, and X-rays
- Health hazards
- Radiation absorbed by the body along with exposure time and distance
- Periodic table
- Element, atom, nucleus, protons, neutrons, electrons
- Atoms
- Number of protons define the element
- Balance of neutrons and protons
- Positive and negative ions
- Isotopes
- Radioactivity
- Ionizing radiation
- Removing electrons
- Potentially hazardous
- Chemical properties of ionized atoms are altered.
- Nonionizing radiation
- Electromagnetic waves
- Sound waves
- Radio waves
- Microwaves
- Testing for radiation in the field
- Information from labels on shipping packages:
- Type
- Activity level
- Fission-capable material
Toxic Products of Combustion
- Combustion is a chemical reaction that generates gases and particulates.
- Can result in release of hazardous chemicals.
- Common chemical by-products:
- Soot
- Carbon monoxide
- Carbon dioxide
- Substances unique and hazardous to humans:
- Carbon monoxide
- Cyanide compounds
- Formaldehyde
- Oxides of nitrogen
Hazard, Exposure, and Contamination
- Identify potential hazards.
- Determine release or potential escape.
- Determine right training, equipment, and protective gear.
- Determine safety risks and what cannot be done.
- Hazard versus exposure
- Understanding the difference
- Contamination
- Transfer of hazardous material or components
- Contaminant
- Exposure and spread
- Removing contaminants
- Complexity varies
- Secondary contamination
- Transfer by direct contact to persons, objects, and environment
- Responders risk spreading contaminants.
- Contaminants can be spread in several ways.
- Stay clean and use PPE.
Chronic and Acute Health Effects
- Chronic health hazard
- Adverse and gradual health effects
- Long-term or multiple short-term exposures
- Exposures can involve all routes of entry.
- Health problems include cancer, loss of lung function, and skin rashes.
- Acute health effects
- Observable health problems such as eye irritation, coughing, dizziness, and skin burns that can appear long after exposure
- Skin irritation and immune system response
- Infectious exposure
- Substance that contains a microorganism or particles that can cause disease
- Contagious exposure
- Bacteria or virus that can be transmitted from person to person
- Toxins
- Poisonous substances produced from metabolic processes
- Poison
- Substance causing adverse health effects
- Toxicity
- A measure of the degree to which something is toxic or poisonous
- Substance properties and dosage
- Magnitude of response
- Concentration of substance and duration of exposure
- Lethal dose (LD) verses lethal concentration (LC)
- Cyanide exposure
- Subcategories
- Benchmark concentration of particular exposure
- LD values
- LC values
- OSHA’s view of exposure:
- Three categories of toxic chemicals
- Three categories of highly toxic chemicals
Summary
- The most fundamental of all actions is the ability to observe the scene and understand the problem you are facing. Think before you act—it could save your life!
- An important first step in understanding the hazards of any chemical is identifying the state of matter and defining whether the substance is a solid, liquid, or gas.
- A critical step in comprehending the nature of the release is identifying the reason(s) why the containment vessel failed.
- Chemical change is not the same thing as physical change. Physical change is a change in state; chemical change describes the ability of a substance to undergo a transformation at the molecular level, which is usually accompanied by a release of some form of energy.
- There are many critical characteristics of flammable liquids, and you should be familiar with each of them.
- When responders respond to hazardous materials incidents, they must fully understand the hazards to minimize the potential for exposure.
- Avoid contamination whenever possible—it will reduce the likelihood of harmful exposures.
- Chronic health effects may occur after years of exposure to hazardous materials. Wear all protective gear to minimize the impacts of repeated exposures.
- All liquids—even water—will develop a certain amount of pressure in the airspace between the top of the liquid and the container.
- Boiling point is the temperature at which the vapor pressure of a liquid equals the surrounding atmospheric pressure.
- Vapor density is a question of comparison: What will the gas or vapor do when it is released in the air?
- Specific gravity is the comparison is between the weight of a liquid chemical and the weight of water.
- Water solubility describes the ability of a substance to dissolve in water.
- Corrosivity is a property of a material that reflects its ability to cause damage on contact with skin, eyes, or other parts of the body.