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Properties and Hazards

Properties and Hazards . Introduction Hazardous materials may be Elements Compounds Mixtures Gaseous Liquid Solids . Properties and Hazards . Introduction They may present a direct threat to health Poison Carcinogens Toxic or highly toxic Irritants Corrosives Sensitizers.

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Properties and Hazards

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  1. Properties and Hazards • Introduction • Hazardous materials may be • Elements • Compounds • Mixtures • Gaseous • Liquid • Solids

  2. Properties and Hazards • Introduction • They may present a direct threat to health • Poison • Carcinogens • Toxic or highly toxic • Irritants • Corrosives • Sensitizers

  3. Properties and Hazards • Introduction • They may be considered dangerous because of their physical hazards • Flammable • Compressed gases • Explosives • Organic peroxides • Oxidizers • Pyrophoric chemicals • Cryogenic materials • Radioactive materials • Water-reactive materials

  4. Properties and Hazards • Introduction • The severity of hazards these materials present range from • Insignificant • Catastrophic • Depends on material and quantity involved

  5. Properties and Hazards • Introduction • Exposures to hazardous materials • Acute • Single occurrence • Chronic • Long-term • Reoccurring

  6. Properties and Hazards • Introduction • Health effects from exposure • Acute • Short-term effects • Appear within hours or days • Vomiting • Diarrhea • Chronic • May take years to appear • Cancer

  7. Properties and Hazards • Hazardous Materials Properties • Awareness level • Need to understand • Basic hazards associated with different classes of hazardous materials • Flammables • Corrosives • Reactives • Operations level • Need to know how hazardous materials behave • Signs and symptoms of an exposure

  8. Properties and Hazards • Hazardous Materials Properties • Matter • Substances that make up everything in the world • Gas • Fluid that has neither independent shape nor volume • Tend to expand indefinitely • Liquid • Fluid that has no independent shape but does have a specific volume • Flow in accordance with the laws of gravity • Solid • Substance that has both a specific shape and volume (without a container)

  9. Properties and Hazards • Hazardous Materials Properties • Flammability • Majority of hazardous materials incidents involve materials that are flammable • Burn • Explode • Flammable hazards depend on • Flash point • Autoignition temperature • Explosive or combustible range

  10. Properties and Hazards • Hazardous Materials Properties • Flash Point • Minimum temperature at which a liquid or volatile solid gives off sufficient vapors to form an ignitable mixture with air near its surface • Vapors will flash • Will NOT continue to burn • DO NOT confuse with Fire Point

  11. Properties and Hazards • Hazardous Materials Properties • Fire Point • Temperature at which enough vapors are given off to support continuous burning • Temperature is usually only slightly higher than the flash point • Liquids and solids themselves do not burn • Vapors they produce burn • As temperature increases, more vapors are produced • Flammable gases have no flash point

  12. Properties and Hazards • Hazardous Materials Properties • Autoignition Temperature/Autoignition Point • Minimum temperature to which the fuel in air must be heated to initiate self-sustained combustion • No independent ignition source • Spontaneously ignites • Considerably higher than the flash and fire points • Ignition temperature is often used synonymously

  13. Properties and Hazards • Hazardous Materials Properties • Flammable, Explosive or Combustible Range • Percentage of the gas or vapor concentration in air that will burn or explode if ignited

  14. Properties and Hazards • Hazardous Materials Properties • Flammable, Explosive or Combustible Range • Lower explosive limit / lower flammable limit • LEL / LFL • Lowest concentration of a vapor/gas that will produce a flash of fire • Concentrations lower than the LEL • Mixture is too lean to burn

  15. Properties and Hazards • Hazardous Materials Properties • Flammable, Explosive or Combustible Range • Upper explosive limit / upper flammable limit • UEL / UFL • Highest concentration of a vapor / gas that will produce a flash of fire • Concentrations higher than the UEL • Mixture is too rich to burn

  16. Properties and Hazards • Hazardous Materials Properties • Vapor Pressure • Pressure exerted by a saturated vapor above its own liquid in a closed container • Pressure produced or exerted by the vapors released by a liquid • Can be expressed in terms of • Pounds Per Square Inch (PSI) • Kilopascals (kPa) • Bars • Millmeters of mercury (mmHg) • Usually found on MSDS • Atmospheres (atm)

  17. Properties and Hazards • Hazardous Materials Properties • Vapor Pressure • The higher the temperature of a substance, the higher the vapor pressure will be • Higher temperature provide more energy to a liquid • Allows liquid to escape into a gas form • The lower the boiling point of a substance, the higher its vapor pressure will be • Used as a general gauge to tell how fast a product will evaporate under normal circumstances

  18. Properties and Hazards • Hazardous Materials Properties • Boiling Point • The temperature at which the vapor pressure of a liquid is equal to or greater than atmospheric pressure • The temperature at which a liquid changes to a gas • 760 mmHg = 14.7 psi or 1 atmosphere

  19. Properties and Hazards • Hazardous Materials Properties • Boiling Liquid Expanding Vapor Explosion • BLEVE • Also called Violent Rupture • Can occur when a liquid within a container is heated • Causes material inside to boil / vaporize • Increases vapor pressure • Exceeds the vessel’s ability to relieve the excess pressure • Most commonly occur when flames contact a tank shell above the liquid level

  20. Properties and Hazards • Hazardous Materials Properties • Melting Point • Temperature at which a solid substance changes to a liquid state • Freezing Point • Temperature at which a liquid becomes a solid • Sublimation • Substances changes from a solid directly Into a gas • Carbon dioxide (dry ice) • Mothballs

  21. Properties and Hazards • Hazardous Materials Properties • Vapor Density • Weight of a given volume of pure gas • Gas compared to the weight of an equal volume of dry air • Air has a value of 1 • Vapor density <1 • Vapor is lighter than air • Vapor density >1 • Vapor is heavier than air • All vapors / gases will mix with air • Spread can not be predicted exactly from vapor density

  22. Properties and Hazards • Hazardous Materials Properties • Solubility • Term expressing the percentage of a material (by weight) that will dissolve in water at ambient temperature • Used for spill clean up methods • Extinguishing agents • Non-water soluble • Liquids remain separate from water • Polar solvent • Liquids mix easily with water

  23. Properties and Hazards • Hazardous Materials Properties • Solubility • Health effects • Water-soluble agents • Cause early upper respiratory tract irritation • Partially water-soluble agents • Penetrate into the lower respiratory system • Delayed symptoms • 12-24 hours • Causes breathing difficulties • Pulmonary edema • Coughing up blood

  24. Properties and Hazards • Hazardous Materials Properties • Miscibility / Immiscibility • The degree or readiness to which two or more gases or liquids are able to mix with or dissolve into each other • Miscible • Two liquids that dissolve into each other in any proportion • Immiscible • Two materials that do not readily dissolve into each other

  25. Properties and Hazards • Hazardous Materials Properties • Specific Gravity • Ratio of the density of a material to the density of some standard material • Heaviness of a material • Water has a value of 1 • Specific gravity <1 • Liquid is lighter than water and will float • Specific gravity >1 • Liquid is heavier than water and will sink

  26. Properties and Hazards • Hazardous Materials Properties • Reactivity • Relative ability to undergo a chemical reaction with another material • The fire tetrahedron • Reactive triangle • Fuel (Reducing Agent) • Heat • Oxygen (Oxidizer) • Activation energy • Required energy to get them started • Starting a fire with a match

  27. Properties and Hazards • Hazardous Materials Properties • Reactivity • Examples • Light-sensitive • Heat-sensitive • Shock-sensitive • Polymerization • Often results in a tremendous release of energy • Designated with a “P” in the ERG • Inhibitors are added in order to control or prevent an undesired reaction

  28. Properties and Hazards • Hazardous Materials Hazards • Health hazards • Directly effect an individual’s health • Poisons • Corrosives • Physical hazards • Present a threat because of the material’s physical properties • Temperature • Radioactivity

  29. Properties and Hazards • Hazardous Materials Hazards • U.S. National Fire Academy (NFA) • Uses a simple classification system • TRACEMP • T Thermal • R Radiological • A Asphyxiation • C Chemical • E Etiological • M Mechanical • P Psychological

  30. Properties and Hazards • Hazardous Materials Hazards • U.S. National Fire Academy (NFA) • Uses a simple classification system • TRACEMP • T Thermal • Thermal harm is the result of exposure to extremes of heat and cold • R Radiological • Refers to nuclear radiation • Alpha • Beta • Gamma

  31. Properties and Hazards • Hazardous Materials Hazards • U.S. National Fire Academy (NFA) • Uses a simple classification system • TRACEMP • A Asphyxiation • Interfere with oxygen flow during normal breathing • Simple asphyxiants • Inert gases that displace or dilute oxygen • Chemical asphyxiants • Blood poisons

  32. Properties and Hazards • Hazardous Materials Hazards • U.S. National Fire Academy (NFA) • Uses a simple classification system • TRACEMP • C Chemical • Toxic • Harm depends on concentration and length of exposure • Corrosive • Harm causes visible destruction

  33. Properties and Hazards • Hazardous Materials Hazards • U.S. National Fire Academy (NFA) • Uses a simple classification system • TRACEMP • E Etiological • Harm involves exposure to a living microorganism • M Mechanical • Causes trauma • Shrapnel during an explosion • P Psychological • Causes strong emotional reaction

  34. Properties and Hazards • Hazardous Materials Hazards • Cryogenics • Refrigerated liquefied gas • Gases that turn into a liquid at or below -130o F • Vaporize rapidly when released from container • Liquid oxygen (LOX) • Liquefied natural gas (LNG) • Nitrogen • Helium • Hydrogen • Argon

  35. Properties and Hazards • Hazardous Materials Hazards • Radiological • Nonionizing radiation • Has enough energy to move atoms around but not change them chemically • Radio waves • Infrared radiation • Microwaves • Ionizing radiation • The most energetic form of radiation

  36. Properties and Hazards • Hazardous Materials Hazards • Radiological • Ionizing radiation • Has sufficient energy to remove electrons from atoms • Disrupts chemical bonds • Called “Ionization” • Causes damage to the human body

  37. Properties and Hazards • Hazardous Materials Hazards • Radiological • Alpha Particles • Lose energy rapidly in matter • Do not penetrate very far • Blocked by paper • Beta Particles • Fast moving • Blocked by aluminum

  38. Properties and Hazards • Hazardous Materials Hazards • Radiological • Gamma Rays • Similar to X-rays • Completely pass through the human body • Radiation hazard • Stopped by a few inches of lead or several feet of concrete • X-rays • Lower energy then gamma rays • Stopped by a few inches of lead or several feet of concrete

  39. Properties and Hazards • Hazardous Materials Hazards • Radiological • Neutrons • Ultrahigh energy particles • Highly penetrating

  40. Properties and Hazards • Hazardous Materials Hazards • Radiological • Exposure pathways • Inhalation • Breathe radioactive materials into the lungs • Can remain in the lungs for a long time • Ingestion • Swallowing radioactive materials • Expose entire digestive system • Direct Exposure • Skin contact

  41. Properties and Hazards • Hazardous Materials Hazards • Radiological • Protection Strategies • Time • Limit exposure time to radiation source • Distance • Increase distance from source • Doubling distance reduces the exposure by a factor of four • Shielding • Lead • Concrete

  42. Properties and Hazards • Hazardous Materials Hazards • Toxic Materials • Nephrotoxic agents • Affect the kidneys • Hematotoxic agents • Affect the blood • Neurotoxic agents • Affect the nervous system • Hepatotoxic agents • Affect the liver

  43. Properties and Hazards • Hazardous Materials Hazards • Toxic Materials • Lethal dose (LD) • The minimum amount of a solid or liquid that will cause death • Median lethal dose (LD50) • Single dose of a substance that can be expected to cause death in 50% of animals • Administered orally • The other half isn’t completely well • They just didn’t die • Lethal dose low (LDLO or LDL) • Lowest administered dose of a material capable of killing a specific test species

  44. Properties and Hazards • Hazardous Materials Hazards • Toxic Materials • Lethal concentration (LC) • Minimum concentration of an inhaled substance in the gaseous state that will be fatal • Usually within 1-4 hours • May be expressed in LC50 • Lethal concentration low (LCLO or LCL) • Lowest concentration of a gas or vapor capable of killing a specified species over time

  45. Properties and Hazards • Hazardous Materials Hazards • Toxic Materials • Immediately Dangerous to Life or Health (IDLH) • An atmospheric concentration of a substance that poses an immediate threat to life • Permissible Exposure Limit (PEL) • Maximum concentration to which the majority of healthy adults can be exposed over a 40-hour workweek • Time-Weighted Average (TWA) • 8-hour period

  46. Properties and Hazards • Hazardous Materials Hazards • Toxic Materials • Permissible Exposure Limit Ceiling Limit (PEL) (C) • The maximum concentration to which an employee may be exposed at any time • Instantaneous • Short-term Exposure Limit (STEL) • The maximum concentration allowed for a 15-minute exposure

  47. Properties and Hazards • Hazardous Materials Hazards • Toxic Materials • Irritants • Toxins that cause temporary but sometimes severe inflammation to the eyes, skin or respiratory system • Attack the mucous membranes of the body • Convulsants • Toxic materials that can cause convulsions • Sensation of difficulty breathing • Painful muscle spasms • 3-30 minutes

  48. Properties and Hazards • Hazardous Materials Hazards • Toxic Materials • Corrosives • Chemicals that destroy or burn living tissues and have destructive effects • With the exception of liquid and gas fuels • Corrosives comprise the largest usage class in industry • Acids • pH <6 • Bases (Alkalis) • pH 8-14

  49. Properties and Hazards • Hazardous Materials Hazards • Toxic Materials • Carcinogens • Cancer-causing agents • Mutagens • Substances or agents that are capable of altering the genetic material in a living cell

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