MANY HAZARDS MAY BE PRESENT AT ANY ONE INCIDENT.THE RESULT OF THE PHYSICAL/CHEMICAL PROPERTIES OF THE MATERIAL OR ITS CHEMICAL REACTIVITY WITH OTHER MATERIALS OR ENVIRONMENT TO WHICH IT IS EXPOSED.

WIND DIRECTION

HOT

WARM

ISOLATION PERIMETER

DECON

THE MINIMUM TEMPERATURE AT WHICH A LIQUID GIVES OFF ENOUGH VAPOS THAT WILL IGNITE AND FLASH OVER BUT WILL NOT CONTINUE TO BURN WITHOUT THE ADDITION OF MORE HEAT

THE MINIMUM TEMPERATURE REQUIRED TO IGNITE GAS / VAPOR WITHOUT A SPARK / FLAME BEING PRESENT.

FLAMMABLE / EXPLOSIVE RANGE/LIMITSTHE CONCENTRATION OF GAS /VAPOR IN AIR THAT WILL BURN IF IGNITED. IT IS EXPRESSED AS A PERSENTAGE THAT DEFINES THE RANGE BETWEEN A LOWER EXPLOSIVES LIMIT (LEL) & AN UPPER EXPLOSIVE LIMIT (UEL). A MIXTURE BELOW THE LEL IS TOO LEAN TO BURN, A MIXTURE ABOVE THE UEL IS TOO RICH TO BURN

FLAMMABLE LIMITSTO RICH

EXPLOSION LIMITTO LEAN100 %13 %7 %0 %

THE POINT AT WHICH A LIQUID CHANGES TO VAPOR . WHERE THE PRESSURE OF THE LIQUID EQUALS ATMOSPHERIC PRESSURE. A MAJOR CONSIDERATION WITH TOXIC SUBTANCES IS HOW THEY ENTER THE BODY. WITH HIGH BOILING POINT LIQUIDS THE MOST COMMON ENTRY IS BY BODY CONTACT, WITH LOW BOILING POINT LIQUIDS, THE INHALATION ROUTE IS THE MOST COMMON AND SERIOUS.

THE TEMPERATURE AT WHICH A SOLID CHANGES PHASE TO A LIQUID IS THE MELTING POINT.THIS TEMPERATURE IS ALSO THE FREEZING POINT, SINCE A LIQUID CAN CHANGE PHASE TO A SOLID.

THE ABILITY OF A SOLID, LIQUID, GAS OR VAPOR TO DISSOLVE IN A WATER / OTHER SPECIFIED MEDIUM.

SPECIFIC GRAVITY IS THE RATIO OF THE DENSITY OF A SUBSTANCE TO THE DENSITY OF THE WATER AT THE TEMPERATURE OF ITS MAXIMUM DENSITY (4 DEGREE C ). IF THE DENSITY OF THE SUBTANCE IS GREATER THAN 1 , IT WILL SINK IN WATER. THE SUBTANCE WILL FLOAT ON WATER IF ITS LESS THAN 1.

ABILITY OF SUBSTANCE TO CHANGE FROM SOLID TO THE VAPOR WITHOUT PASSING THROUGH LIQUID PHASERELIEF LIQUID / SOLID CAN PASS INTO THE VAPOR (EVAPORATION)

IS THE WEIGHT OF A VOLUME OF PURE VAPOR OR GAS (WHICH NO AIR PRESENT) COMPARED TO THE WEIGHT OF AN EQUAL VOLUME OF DRY AIR AT THE SAME TEMPERATURE AND PRESSURE. IT IS CALCULATED AS THE RATIO OF THE MOLECULAR WEIGHT OF THE GAS TO THE ADVERAGE MOLECULAR OF AIR. A VAPOR DENSITY FIGURE LESS THAN 1 INDICATES THAT THA VAPORS IS LIGHTER THAN AIR AND WILL TEND TO RISE IN A RELATIVELY CALM ATMOSPHERE.A FIGURE GREATER THAN 1 INDICATES THAT THE VAPOR IS HEAVIER THAN AIR.

THE PRESSURE EXERTED BY A VAPOR WITHIN AGAINST THE SIDES OF A CLOSED CONTAINER IS CALLED VAPOR PRESSURE . IT IS TEMPERATURE DEPENDENT.AS THE TEMPERATURE INCREASES, SO DOES THE VAPOR PRESSURE. THUS ,MORE LIQUID EVAPORATES /VAPORIZES. The vapor pressure of substance at 100 F is always higher than the vapor pressure at 68 F . Vapor pressure reported in millimeters of mercury (mm Hg ) 760 mm Hg is equivalent to 14.7 psi. / a atmosphere. Materials with vapor pressure greater than 760 mm Hg are usually found as gases. The lower the boiling point of a liquid, the greater vapor pressure at a given temperature.

AMMONIA ANHYDROUS NH 3 PROPERTIES

FLAS

P.

Gas

IGN

TEM

651c

FLAM

LIM

LEL

16 %

UEL 25%

SP.

GR.

-

VAP.

DEN.

0.6

BOIL.

P.

-33 c

WAT.

SOL.

Yes

EXT.

METH

Stop the

flow

HAZ.

IDEN

HT

3

FLA

1

REA

0

FACTOR INFLUENCE- NATURE OF HAZMAT INVOLVED- QUANTITY INVOLVED- CONTAIMENT SYSTEM AND TYPE STRESS ( PRESSURIZED / NON )- PROXIMITY OF EXPOSURE : RATE AND DISTANCE DISPERSION- LEVEL OF AVAILABLE RESOURCES WILL INFLUENCE THE LEVEL OF RISK

THE TYPES OF MAJOR INCIDENT- LARGE SCALE TOXIC HAZARDS- EXPLOSION HIGHLY REACTIVE / UNSTABLE MATERIALS- EXPLOSION STORED PRESSURE- LARGE SCALE FIRE HAZARD - LARGE SCALE EXLPOSION HAZARD BLEVE