1. Hazardous Materials: Properties and Effects2
Hazardous Materials: Properties and Effects

2. 2 Objectives (1 of 7) Describe the following properties: Boiling point
Chemical reactivity
Corrosivity (pH)
Flammable (explosive) range [lower explosive limit (LEL) and upper explosive limit (UEL)]
Flash point

3. 2 Objectives (2 of 7) Ignition (autoignition) temperature
Particle size
Persistence
Physical state (solid, liquid, gas)
Radiation (ionizing and non-ionizing)
Specific gravity

4. 2 Objectives (3 of 7) Toxic products of combustion Vapor density
Vapor pressure
Water solubility
Physical change and chemical change

5. 2
Objectives (5 of 7)
Describe the differences between the following pairs of terms:
Contamination and secondary contamination
Exposure and contamination
Exposure and hazard
Infectious and contagious
Acute and chronic effects
Acute and chronic exposures

6. 2
Objectives (7 of 7)
Describe the routes of exposure to hazardous materials for humans

7. Chemical and Physical Properties (1 of 2)
Characteristics of a substance
Important to understand for hazardous substances/WMD
Basis of good decisions on response

8. Chemical and Physical Properties (2 of 2)
Are measurable
They include:
Vapor density
Flammability
Corrosivity
Water reactivity

9. The state of matter identifies the hazard as a solid, liquid, or gas.2
State of Matter (1 of 2)
The state of matter identifies the hazard as a solid, liquid, or gas.

10. 2 State of Matter (2 of 2) Helps predict what substance will do
How will it escape its container?
Why did the container fail?
Influences the incident’s duration
In turn, informs emergency response plan

11. 2 Physical Change Can occur when chemicals are subjected to Heat Cold
Pressure

12. 2 BLEVE Boiling Liquid/Expanding Vapor Explosion
Pressurized liquefied materials inside closed vessel are exposed to high heat
Results in physical change from liquid to gas
Examples: propane, butane
Expansion ratio: Describes the volume increase that occurs

13. 2 Chemical Reactivity Also known as chemical change
Ability to transform at molecular level
Usually releases some form of energy
Examples
Steel when it rusts
Wood when it burns

14. “You Are the Responder” Case Study2
“You Are the Responder” Case Study
What physical/chemical changes caused:
The rags to spontaneously ignite?
Failure of the small, propane cylinder?
Fire fighters and residents to experience skin irritation?

15. Critical Characteristics of Flammable Liquids2
Critical Characteristics of Flammable Liquids
Flash point
Ignition temperature
Flammable range
Only substances in gaseous or vapor state will combust
Solids and liquids produce vapor, then ignite

16. 2
Flash Point (1 of 3)
Minimum temperature at which ignition results in flash fire
Fire will go out once vapor fuel is consumed

17. 2
Flash Point (2 of 3)
Responders should always be mindful of ignition sources at flammable/combustible liquid incidents.

18. 2
Flash Point (3 of 3)
Low flash point = higher ignition temperatures and vapor pressures
Examples: Gasoline, ethyl alcohol, acetone
High flash point = lower ignition temperatures and vapor pressures
Example: #2 grade diesel fuel

19. 2 Fire Point Temperature at which sustained combustion of vapor occurs
Usually slightly higher than flash point

20. 2 Ignition Temperature Also known as autoignition temperature
Temperature at which heated fuel ignites and continues to burn
No external ignition source necessary

21. 2
Flammable Range
Concentrations (%) of flammable vapor and air needed for fuel/air mixture to burn
Defined by lower and upper limits:
Lower explosive limit (LEL)
Upper explosive limit (UEL)
More dangerous material has wider range

22. 2 Vapor Pressure (1 of 3) Pertains to liquids inside closed container
May be expressed in:
Pounds per square inch (PSI)
Atmospheres (atm)
Torr
Millimeters of mercury (mm Hg)

23. 2
Vapor Pressure (2 of 3)
The vapors released from the surface of any liquid must be contained if they are to exert pressure.

24. 2 Vapor Pressure (3 of 3) Influenced by ambient temperature
High temp. → increased vapor pressure
Low temp. → decreased vapor pressure
Causes liquid to evaporate when released
High vapor pressure → evaporates quickly
Low vapor pressure → evaporates slowly

25. 2 Boiling Point (1 of 2) Liquid continually gives off vapors
Molecules must overcome downward force of atmospheric pressure
If maintained, all liquid will turn into gas

26. The concept of boiling point versus atmospheric pressure.2
Boiling Point (2 of 2)
The concept of boiling point versus atmospheric pressure.

27. 2 Vapor Density (1 of 2) Weight of vapor compared to weight of air
Expressed numerically (e.g., in the MSDS)
Air has set vapor density of 1.0
Vapor density > 1.0 = heavier; < 1.0 = lighter
Affects gas’ behavior during release
Lighter-than-air gases: “4H MEDIC ANNA”

28. 2
Vapor Density (2 of 2) A. B.
A. Vapor density < 1.0 over the cylinder with the gas leak rising upward. B. Vapor density > 1.0 over the cylinder with the heavier-than-air leak.

29. 2
Specific Gravity (1 of 2)
Compares weight of liquid chemical to weight of water
Water has specific gravity of 1.0
Materials with specific gravity < 1.0 float
Materials with specific gravity > 1.0 sink
Most flammable liquids float on water

30. Gasoline will float on water, whereas carbon disulfide will not.2
Specific Gravity (2 of 2)
Gasoline will float on water, whereas carbon disulfide will not.

31. 2 Water Solubility Ability of substance to dissolve in water
Water most often used to extinguish fires
Reacts violently with some chemicals (e.g., sulfuric acid, metallic sodium, magnesium)

32. 2 Corrosivity (1 of 3) Ability of a material to cause damage to
Skin, eyes, other body parts
Clothing, rescue equipment
Corrosive chemicals should be taken seriously
Materials require unique response tactics

33. 2 Corrosivity (2 of 3) Two types: Acids and bases Defined by pH
Acids have pH greater than 7
Bases have pH less than 7
pH 7 is neutral
pH < 2.5 or > 12.5 considered strong

34. 2
Corrosivity (3 of 3)
The pH scale.

35. Toxic Products of Combustion2
Toxic Products of Combustion
Materials decompose under heat, resulting in hazardous chemical compounds
Smoke may not be just smoke!
Soot, carbon monoxide, carbon dioxide, water vapor, formaldehyde, cyanide compounds, nitrogen oxides

36. 2 Hazard and Exposure Hazard: Material capable of causing harm
Exposure: Process by which people, animals, the environment, and equipment come into contact with hazardous material

37. 2 Contamination Residue from released chemical
Decontamination: Process of residue removal
Secondary contamination is transferred from source by direct contact
PPE protects if contact cannot be avoided
Does not enable unlimited contact

38. Harmful Substances’ Routes of Entry Into Body (1 of 2)
The four ways a harmful substance can enter the body.

39. Harmful Substances’ Routes of Entry Into Body (2 of 2)
Inhalation: Through lungs
Absorption: Through skin
Ingestion: Through gastrointestinal tract
Injection: Through cuts or breaches in skin

40. 2
Inhalation (1 of 2)
Hazardous materials/WMD, corrosive materials, particles
SCBA offers excellent protection
Infectious and contagious organisms also hazard
Example: Anthrax

41. 2
Inhalation (2 of 2)
Air-purifying respirators protect against certain airborne chemical hazards
More comfortable
Allow longer work periods
Image: Courtesy Sperian Respiratory Protection

42. 2 Absorption Through skin, eyes, nose, mouth
Asphyxiants may form, causing suffocation
Some agents are carcinogens
Aggressive solvents (e.g., paint stripper and hydrofluoric acid)

43. 2 Ingestion Chemicals enter body through GI tract
May occur when rotating out from emergency
After hazardous work, wash before drinking/eating

44. 2 Injection Via cuts, abrasions, open wounds
Address these before reporting for duty

45. Chronic Health Hazards2
Chronic Health Hazards
Appear after long-term exposure to hazard
Also after multiple short-term exposures
Target organ effect
Example: Asbestosis

46. 2 Acute Health Effects Occur after short, acute exposure
Examples: Acid burns (sulfuric acid), breathing difficulties, and skin irritation (formaldehyde, a “sensitizer")

47. 2 Toxicity Degree to which something is toxic or poisonous
Or, one such substance’s adverse effects
Lethal dose (LD)
Lethal concentration (LC)
OSHA descriptions based on LD and LC

48. 2 Summary (1 of 3) Know chemical and physical properties of substances
Important to making informed response
Understand physical and chemical changes
Be familiar with characteristics of flammable liquids

49. 2
Summary (2 of 3)
Understand hazards before responding, to minimize potential for exposure
Avoid contamination whenever possible
Hazardous substances/WMD enter the body through inhalation, ingestion, injection, and absorption

50. 2
Summary (3 of 3)
May be used as WMD: Nerve agent, blister agent, blood agent, choking agent, irritant, convulsant
HEPA filters and SCBA protect lungs
Chronic health effects occur after years of exposure—wear protective gear!