Title: Fire Security and Safety
Course: IN 2001 Principle of Information Assurance > Section: Module 9: Chapter Nine

Fire Security and Safety

1. The most serious threat to physical security and the safety of the people who work in an organization is the possibility of fire.
2. Fires account for more property damage, personal injury and death than any other threat to physical security.
3. As a result, it is imperative that physical security plans examine and implement strong measures to detect and respond to fires and fire hazards.

Fire Detection and Response
1. Fire suppression systems are devices that are installed and maintained to detect and respond to a fire, potential fire or combustion situation.
2. These devices typically work to deny an environment of one of the three requirements for a fire to burn: temperature, fuel and oxygen.
3. Water and water mist systems reduce the temperature of the flame to extinguish it and to saturate some categories of fuels to prevent ignition.
4. Carbon dioxide systems rob fire of its oxygen.
5. Soda acid systems deny fire its fuel, preventing the fire from spreading.
6. Gas-based systems disrupt the fire’s chemical reaction but leave enough oxygen for people to survive for a short time.
7. Before a fire can be suppressed, it must be detected.
8. Fire Detection
  - Fire detection systems fall into two general categories: manual and automatic
  - Manual fire detection systems include human responses, such as calling the fire department, as well as manually activated alarms, such as sprinklers and gaseous systems
  - During the chaos of a fire evacuation, an attacker can easily slip into offices and obtain sensitive information.  As part of a complete fire safety program, it is advisable to designate individuals as floor monitors
  - There are three basic types of fire detection systems: thermal detection, smoke detection and flame detection
  - Thermal detection systems contain a sophisticated heat sensor that operates in one of two ways: fixed temperature and rate-of-rise
  - Smoke-detection systems are perhaps the most common means of detecting a potentially dangerous fire, and they are required by building codes
  - Smoke detectors operate in one of three ways:
    - Photoelectric sensors project and detect an infrared beam.  If the beam is interrupted, the alarm or suppression system is activated
    - Ionization sensors contain a small amount of a harmless radioactive material within a detection chamber. When certain by-products of combustion enter, a change in the level of electrical conductivity activates the detector
    - Air-aspirating detectors take in air, filter it and move it through a chamber containing a laser beam.  If the laser beam is diverted or refracted by smoke particles, the system is activated
  - The flame detector is a sensor that detects the infrared or ultraviolet light that is produced by an open flame. These systems require direct line-of-sight with the flame and compare the flame “signature” to a database to determine whether or not to activate the alarm and suppression systems
  - While highly sensitive, flame detection systems are expensive and must be installed where they can scan all areas of the protected area
9. Fire Suppression
  - Fire suppression systems can consist of portable, manual or automatic apparatus.  Portable extinguishers are rated by the type of fire they can combat:
    - Class A: Fires of ordinary combustible fuels. Class A fires are extinguished by using water and multipurpose, dry chemical fire extinguishers
    - Class B: Fires fueled by combustible liquids or gases, such as solvents, gasoline, paint, lacquer and oil. Class B fires are extinguished by using carbon dioxide, multipurpose dry chemical and Halon fire extinguishers
    - Class C: Fires with energized electrical equipment or appliances.  Class C fires are extinguished by using carbon dioxide, multipurpose, dry chemical, and Halon fire extinguishers
    - Class D: Fires fueled by combustible metals, such as magnesium, lithium, and sodium.  Class D fires are extinguished by using special extinguishing agents and techniques
  - Manual and automatic fire responses can include installed systems designed to apply suppressive agents. These are usually either sprinkler or gaseous systems
  - Sprinkler systems are designed to apply liquid, usually water, to all areas in which a fire has been detected
  - In sprinkler systems, the organization can implement wet pipe, dry-pipe or pre-action systems
  - Water mist sprinklers are the newest form of sprinkler systems and rely on ultra fine mists instead of traditional shower-type systems
10. Gaseous Emission Systems
  - Chemical gas systems can also be used to suppress fires.  Until recently, there were only two major types of gaseous systems: carbon dioxide and Halon
  - Carbon dioxide robs a fire of its oxygen supply.  Halon is a clean agent, which means that it does not leave any residue when dry, nor does it interfere with the operation of electrical or electronic equipment. Unfortunately, the EPA has classified Halon as an ozone-depleting substance and therefore, new installations are prohibited
  - Alternative clean agents include the following:
    - FM-200
    - Inergen
    - Carbon dioxide
    - FE-13 (trifluromethane)