9 PHYSICAL PROPERTIES OF HAZARDOUS MATERIAL

9 PHYSICAL PROPERTIES OF HAZARDOUS MATERIAL

FLAMMABILITY

VAPOR PRESSURE

STATE OF MATTER

• THE GAS RELEASED BY LIQUID
• VAPOR PRESSURE MEASURES A SUBSTANCE'S TENDENCY TO EVAPORATE.
• VAPOR PRESSURE RISES AS THE TEMPERATURE INCREASES.

BOILING POINT

• INVOLVES FLAMABLE MATERIALS
• DEPENDS ON FLASH POINT, AUTOIGNITION TEMPERATURE, AND FLAMMABLE, COMBUSTIBLE, OR EXPLOSIVE RANGE.

• THE TEMPERATURE AT WHICH VAPOR PRESSURE IS EQUAL TO OR GREATER THAN ATMOSPHERIC PRESSURE.
• USUALLY EXPRESSED IN FAHRENHEIT (CELCIUS)
• WHEN A LIQUID CONTAINER BOILS, AND THE VAPOR IS RELEASED, IT EXPANDS RAPIDLY AND IF IGNITABLE, IT WILL SEND FLAMES AND CONTAINER PIECES IN ALL DIRECTIONS

LIQUID MATTER:

GASEOUS MATTER:

Vapor Density

• GIVES OFF VAPORS CAUSING A POTENTIAL INHALATION HAZARD.
• FLOWS OR POOLS ALONG CONTOURS IN THE FLOOR OR GROUND, MAKING THEM EASIER TO CONTAIN.
• PRIMARILY A CONTACT HAZARD (SPLASHING)

• Vapor Density is the weight of pure vapor or gas compared to the weight of an equal volume of dry air, at the same temperature and pressure.
• Ambient air has a vapor density of 1.
• A vapor density less than 1 indicates a vapor lighter than air.
• A vapor density greater than 1 indicates a vapor heavier than air.

• Most gases have a vapor density greater then 1, so they sink.

• MOVES ACCORDING TO WIND AND AIR MOVEMENT
• COMPRESSED GASES EXPAND RAPIDLY WHEN RELEASED, POTENTIALLY THREATENING LARGE AREAS.
• CAN CREATE A POTENTIAL INHALATION HAZARD.

Solubility

• Water Solubility- the percentage of a material that dissolves in water at an ambient temperature.
• Knowing a material's solubility can help determine appropriate spill cleanup methods and extinguishing agents.
• Non- soluble liquids tend to separate and remain that way.

Specific Gravity

• The density of a substance compared to the density of some standard material, typically water.
• Example: If a volume of a material weighs 8 lbs, an equal volume of water would weigh 10 lbs.
• Material with a specific gravity of less than 1 will float on water, greater than 1 will sink.

• Most flammable liquids have specific gravity of less than 1.

Persistence

• The persistence of a chemical is its ability to remain in the environment.
• Persistent chemicals remain effective at their point of dispersion for a long time, whereas less persistent chemicals quickly dissipate (break down).

Reactivity

• The ability of a substance to chemically react with other material.
• Reactive materials are classified as unstable in most circumstances.
• The fire tetrahedron is used to give an explanation as to why this happens.
• All chemical reactions require activation energy to get started.
• The oxidizing agent in the reactivity triangle provides the oxygen necessary for the chemical reaction.
• The reducing agent is the fuel source for the reaction.
• Another type of chemical reaction is Polymerization, in which a catalyst causes molecules to combine into a chain.
• Inhibitors are materials that slow down or prevent unwanted chemical reactions.

Wrap up

• What were the 9 Physical properties and behaviors of hazardous materials?
• How does this help firefighters in predicting a chemical's behavior at a scene?

SOLID MATTER:

PHYSICAL PROPERTIES

• TYPICALLY REMAINS IN PLACE, BUT THEY CAN BE MOVED BY EXTERIOR FORCES SUCH AS WIND AND WATER.
• A SMALLER PARTICLE SIZE STAYS SUSPENDED IN THE AIR FOR MUCH LONGER THAN LARGER PARTICLES, THAT SETTLE FASTER.

• STATE OF MATTER
• FLAMMABILITY
• VAPOR PRESSURE
• BOILING POINT
• VAPOR DENSITY
• SOLUBILITY
• SPECIFIC GRAVITY
• PERSISTENCE
• REACTIVITY

JOB PERFORMANCE REQUIREMENTS:

DESCRIBE THE PHYSICAL PROPERTIES OF HAZARDOUS MATERIALS (NFPA 472, 5.2.3)

BY: ANNA PADEN

• PERIOD 6
• PAGE 1313-1318
• WORKBOOK QUESTIONS 1-7 MATCHING