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Highly Effective, Low Toxicity, Low Environmental Impact Total Flooding Fire SuppressantsHalon 1301 (CF3Br) has been used for decades as the primary fire suppression agent for areas where powder agents cannot be used because of concerns for sensitive equipment. Halon 1301 is an excellent extinguishing agent, effective at about 3% in air and quite non-toxic. It has an effective exposure limit much greater than its extinguishing concentration, so it can be used in normally occupied areas. The ability of a chemical to destroy stratospheric ozone is its ozone-depletion potential (ODP). ODP is the amount of ozone destroyed per pound of a chemical, relative to the standard CFC-11 with an ODP = 1.0. Because halons have been implicated in stratospheric ozone depletion, their production was stopped at the end of 1995 under the provisions of the Montreal Protocol plus later amendments. In the US, the Clean Air Act Amendments of 1990, Presidential directives, and DoD Directive 6050.9 implemented this phaseout. These regulations and penalties have provided strong incentives for US businesses to decrease CFC use. The Omnibus Budget Reconciliation Act of 1989 mandates high Federal taxes on CFCs and halons, designed to price them out of the market. The taxes also capture for the government the windfall profits that would otherwise go to producers as scarcity drives up prices. Several replacements have been developed for Halon 1301. One is carbon dioxide, which has been used as a firefighting agent for many years. However, a high concentration of carbon dioxide is necessary to inert fuels. The effective concentration for inerting with carbon dioxide is approximately 29%, which is above the concentration lethal to humans. HFC-227ea is being used extensively to replace Halon 1301 systems in nominally occupied areas and some normally unoccupied areas. However, since the effective concentration of HFC-227ea is about three to four times that of Halon 1301 the extinguishing systems have to be larger and new extinguishing systems have to be installed. HFC-125 is also being sold as an extinguishing agent (Nimitz). It has problems similar to HFC-227ea, with a greater concentration needed for effectiveness and the need to use a larger system. This is a particularly onerous penalty in aircraft and spacecraft, where weight and space are extremely important, and substitution is often impossible in existing aircraft due to space limitations.
Document ID
20010067280
Acquisition Source
Kennedy Space Center
Document Type
Conference Paper
Authors
Glass, S. M. (Environmental Technology and Education Center Albuquerque, NM United States)
Dhooge, P. M. (Environmental Technology and Education Center Albuquerque, NM United States)
Nimitz, J. S. (Environmental Technology and Education Center Albuquerque, NM United States)
Date Acquired
August 20, 2013
Publication Date
February 1, 2001
Publication Information
Publication: Proceedings of The 4th Conference on Aerospace Materials, Processes, and Environmental Technology
Subject Category
Nonmetallic Materials
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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IDRelationTitle20010067226Collected WorksProceedings of the 4th Conference on Aerospace Materials, Processes, and Environmental Technology
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