Prelim Arson

• Liquids - fluid that do not generate more than 40 psia when heated to 100 degrees °F
• PSIA means Pound-per-square inch absolute
• If the total atmospheric pressure is above/over 40 it means it is a GAS
• if the total atmospheric pressure is below or lower than 40 it means it is a LIQUID
• TYPES OF LIQUID:

  1. Flammable Liquid
  2. Combustible Liquid
• Flammable Liquid - These are liquids with a flashpoint below 100 degrees °F and a vapor pressure not over 40 psia at 100°F
• Flammable Liquid - These are liquids with a flashpoint below 100 degrees °F and a vapor pressure not over 40 psia at 100°F
• Class 1a - has a flash point below 73 °F, and a boiling point below 100 °F
• Class 1b - has a flash point below 73°F, and a boiling point above 100°F
• Class 1c - has a flash point below 100°F, but not below 73°F
• Combustible Liquids - Liquids that have a flashpoint at or above 100°F
• Class II - any liquid having a flashpoint at or above 100°F and below 140°F
• Class IIIa - any liquid having a flashpoint at or above 140°F and below 200°F
• Class IIIb - any liquid having a flashpoint at or above 200°F
• Slopover - water trapped at bottom of storage tanks vaporizers from heat expanding and expelling contents above it
• chemical properties - the ability of the gas to react within it or with other materials
• flammable gas - any gas that which burn in normal concentration of oxygen in the air
• non-flammable gases - any gases that will not burn in air. Some of these will support combustion and are called oxidizers
• non-flammable gases - any gases that will not burn in air. Some of these will support combustion and are called oxidizers
• Reactive gases - any gases that will react within itself or with other materials under conditions other than fire e. shock, heat, etc.
• Toxic gases - gases that may complicate firefighting efforts due to its serious life hazards
• Physical Properties - is the physical behavior of a gas both outside and inside its container and when accidentally released
• Compressed gases - matter which is solely in a gaseous state in its container with a lower pressure limit 25psig at normal temperatire of 70°F to 100°F
• Liquified gases - Exists partly as a gas and partly as liquid at normal temperature inside the container...
• Cryogenic gases - gas which remains as liquified gas in its container at temperature far below normal temperature
• fuel gases - gases which burn with air to produce heat, power, or light
• industrial gases - gases used in industrial processes ex. water treatment, welding and cutting, etc.
• Medical gases - used for medical purposes ex. therapy and anesthesia
• The most common flammable gas is NATURAL GAS
• METHANE - lighter than air and not toxic
• Hydrogen - difficult to keep in the container and lighter than air. it is extremely flammable
• Ethylene oxide - gas at room temperature and it has extremely wide explosive range
• Oxidizer - can burn inside its own container
• Oxygen is the most common non-flammable gas. it also does not burn but supports combustion
• Combustible solids are those which ignite burn and change chemically when subjected to heat or fire. The heat must be approximately 350°F or higher. Above this temperature, ordinary materials will give off enough vapors and gases to burn. ex. wood,paper, cloth
• Combustible Materials - most combustible metals are chemical elements which are part of earth's composition. ex, potassium
• Pyrophoric = reacts violently when it contacts air
• Naphthalene - does not burn, gives off flammable vapors at 174°F
• Plastic sheeting - a translucent, corrugated, plastic-impregnated fiberglass panels used for natural illumination of structures. Most types of it are slightly less combustible than wood, but still burn readily
• Class - non combustible, and its normal brittleness is increased by sudden colling. This causes it to crack and shatter