SECTION 2 TERMINOLOGY

HAZARDOUS MATERIALS PROPERTIES

What you don’t know can hurt you Remember, “Knowledge is power” If you don’t know-don’t go

DEFLAGRATION SPEED OF FLAME PROPAGATION IS LESS THAN 1250 FEET PER SECOND (SUB SONIC) IF CONFINED CAN STILL CAUSE VIOLENT RUPTURE: PROJECTILE HAZARD “WOOF”

DETONATION SHOCK WAVE PRODUCED IS FASTER THAN 1250 FEET PER SECOND Nitroglycerine9,300 fps Picric acid8,200 fps TNT7,300 fps “BOOM”

FLASH POINT minimum temperature at which sufficient vapor is present to form a combustible mixture with air temperature of the fuel, itself not the ambient temperature ambient temperature above flash point - fire hazard EXTREME gasoline F ethylene glycol F

Flammable or Explosive Limits Lower Explosive Limit (LEL) Minimum volume percent of a material in air that will support combustion If monitored concentration is approaching the LEL, fire or explosion hazard is EXTREME

Flammable or Explosive Limits Upper Explosive Limit (UEL) Maximum volume percent of a material in air that will support combustion If you are in this area you are in great danger! Your exit will take you through a flammable atmosphere!

Flammable Range Flammable concentration between the LEL and UEL % methane in air LEL UEL too lean too rich

Flammable Range A broad flammable range is more dangerous % fuel in air too lean LEL UEL too rich A low LEL is also hazardous (less room for error)

common fuels and their flammable limits FUELLELUEL methane5%15% gasoline1.3%7.1% propane2.1%9.5%

SPECIFIC GRAVITY weight of a liquid compared to water greater than 1 will sink (heavier) less than 1 will float (lighter) solubility is a consideration

VAPOR DENSITY The weight of a gas compared to air A vapor density greater than 1 indicates the gas is heavier than air A vapor density less than 1 indicates the gas is lighter than air useful for predicting areas of high concentration

molecular size (weight) determines vapor density 1 11 Nitrogen = 14 Hydrogen = =17 14 NH 3 anhydrous ammonia air = =.6

Corrosives and the pH scale pH is a reliable indicator for predicting the destruction of: Body tissues Property/Equipment Extreme pH may cause exothermic reactions with other materials producing hazardous by-products

The pH scale Is related to the H + concentration Ranges from 0 to 14 7 is considered “neutral” < 7 is “acidic” > 7 is “basic”, “caustic” or “alkaline” pHs 14 are possible

NEUTRAL ACIDICBASIC