2. METODOLOGÍA DE ESTUDIO
2.1.1 Aspectos específicos del ámbito de estudio
2.1.2.1 Sectores económicos de la Región de Murcia
Purpose
This guideline provides information about halons as fire suppressants and suggests alternatives to them.
Content
General Overview SO.32-2
Guideline SO.32-2
I. Fixed Halon Systems SO.32-2
II. Portable Halon Extinguishers SO.32-4
III. Decommissioned Halon Systems and Portable Extinguishers SO.32-4
Resources SO.32-5
General Overview
The Montreal Protocol agreement phases out production and consumption of CFCs and halons by 1995 except for those essential services where alternatives are not yet
available. (See also Health, Safety and Environmental Guideline PP.2
Chlorofluorocarbons Usage and Disposal, in this manual.) Therefore, all existing and planned applications for these substances should be evaluated and reduced or eliminated wherever possible.
Halon that we no longer need should be stored (banked) so that it cannot be discharged to the environment but is available for recharging existing systems.
Guideline
I. Fixed Halon Systems
A. General
The general guideline for fixed fire suppressant systems is the following:
1. Do not install new additional halon systems.
2. Leave existing halon systems in place until it is necessary to replace or recharge them. At that time,
a. Review the justification for a fixed extinguishing system.
b. Consider alternative agents if a fixed extinguishing system is justified.
c. Replace or recharge the halon systems if alternatives are unavailable and halon is available.
d. Not discharge halon while testing any fixed system.
e. Store (bank) unused halon obtained from decommissioned systems securely.
B. Testing System Reliability
Testing or false trips are the main cause of halon releases; therefore, releases can be minimized if halon discharge testing is eliminated. Other tests that can confirm the reliability of halon systems include:
1. At least annually, inspect and test (but not discharge test) all systems thoroughly to ensure that they are in full operating condition.
2. At least semiannually, check the quantity of agent and the pressure in the refillable containers.
If a container shows a loss in net weight or level of more than five percent or a loss of pressure (adjusted for temperature) of more than ten percent, it should be replaced or refilled.
3. At least quarterly, inspect and test all components of the enclosed space that are required to make the halon system effective. These include but are not limited to:
a. Automatic door, louver, and vent closures b. Automatic ventilation shutdown systems c. Electrical de-energizing systems
d. All detection systems for smoke, flame, heat, etc.
C. Fire Protection Alternatives to Halon Systems
1. Computer, Control, and Electrical Switchgear Rooms
The best alternative to halon in these areas is to install a detection system and an automatic sprinkler system.
Note: Do not use CO2 in enclosed spaces where people may be working.
Anyone trapped in a CO2-filled area will probably be asphyxiated. In a normally unmanned, critical facility in which people may be working, a product — marketed under the name, Inergen — that contains 52 percent nitrogen, 40 percent argon, and 8 percent CO2 can be used. Note that a full-flood fire extinguishing system does not eliminate the damage to the equipment caused by a fire in the equipment.
a. Reducing Fire Risk
1) Reduce to a minimum all combustible solids in computer equipment room(s).
2) Store paper or other flammables away from the room itself.
3) Locate offices outside computer equipment rooms.
4) Separate rooms with fire-rated walls.
5) Select plenum wiring (wiring that will not support combustion) for equipment.
b. Detection System
1) Select an approved smoke-detection system, one that annunciates at a location manned 24 hours a day.
2) Provide a remote, well-identified means of cutting off the electrical power to the equipment located inside the facility.
c. Sprinkler System
1) An automatic sprinkler system is intended to minimize structural damage to a facility or building when initial, fire-suppression (e.g., fire extinguishers) efforts fail.
2) After the emergency, the facility's computer equipment (that is wet from the sprinkler system but not damaged by the fire) can usually be dried and will continue to function properly.
3) A temperature high enough to activate a sprinkler system may damage computer equipment.
4) To minimize damage from the very rare incidence of a leaking sprinkler head, we should request that designers locate sprinkler heads to
minimize the exposure to equipment.
5) To minimize mechanical damage, we should request installers to recess sprinkler heads in the ceiling.
2. Turbine Enclosures
CO2 systems may be selected for turbine enclosures because, as a routine, people do not work inside these areas. However, a positive means of disengaging the turbine's CO2 protection should be provided and used whenever anybody enters the enclosure.
3. Existing Systems
To reduce the potential for false discharges, consider modifying systems from automatic to manual in facilities manned 24 hours a day.
A good detection system with an alarm should allow time to investigate the situation and decide whether or not it is one of the following:
a. A malfunction
b. An incident that can be suppressed by a portable extinguisher c. One that needs full flood
Note: In facilities manned only part time, an abort switch should be used to avoid false discharges during the time facilities are manned.
II. Portable Halon Extinguishers
The general guideline for portable halon extinguishers is that small Halon 1211
extinguishers are acceptable in control, computer, and electrical switchgear rooms until satisfactory alternatives are developed and available, at which time Halon 1211 should no longer be purchased.
III. Decommissioned Halon Systems and Portable Extinguishers
Halon can either be banked in place or sent to an offsite banking facility operated by contractors. Never discharge surplus halon to the atmosphere unless discharging is absolutely required to eliminate an unsafe condition.
A. Banking Unused Halon in Place
If bottles are stored locally, they should be inspected and weighed at least annually to make certain they are not leaking halon. If they are losing halon, they should be sent to a reclamation facility where the halon can be recycled.
1. Preparing and Storing Onsite
When a halon system is taken out of service, bottles can be disconnected, plugged, and capped and left in their present location. This storage area was designed for them and may be the safest place to leave them.
Keeping them onsite makes them available for use as replacement cylinders for other similar critical halon systems, provided the cylinders are of the same size and thread configuration.
2. Alternative Sites a. Local
Alternatively, halon cylinders can be moved to a warehouse or other storage area out of the sun and secured properly.
b. Other Corporate Sites
If there are no local applications for the cylinders, contact Chevron USA Purchasing who can inventory the bottles for use elsewhere in the corporation.
B. Recycling Halon
If banking surplus halon onsite is inappropriate, it can be sent to a reclamation facility for recycling. These facilities are being set up around the world. Typically, the reclaimers will weigh the halon, recycle it, and store it — allowing re-purchase up to 60 percent of the amount of halon they receive.
Contact Chevron Research and Technology Company's Fire Protection Team in the Health, Environment and Safety Group in Richmond, California, for more
information on those reclamation operations closest to a particular facility.
Resources
Final Report of the Halons - Technical Options Committee. United Nations Environment Program. Montreal Protocol Assessment Technology Review.
Halon 1301 Fire Extinguishing Systems. NFPA-12A. Quincy, MA: National Fire Protection Association, 1992.
“Halon Application Within the Oil and Gas Exploration and Production Industry.” The E&P Forum Position Paper. Report No. 2.50/171. E&P Forum, March, 1991.
Ozone Depleting Substances Policy. Australia: Woodside Group of Companies, May 24, 1991.