To serve existing applications depending on equipment that cannot be retrofitted cost-effectively, the U.S. EPA encourages halon banking programs. The Department of Defense maintains such a bank for mission-critical systems, managed by the Defense Logistics Agency, which also serves as the buffer needed while new agents are identified and systems developed for new platforms. In the commercial sector, users have undertaken similar actions to redeploy and bank halon. Private-sector businesses have sprung up to work the halon recycling market, and the non-profit Halon Recycling Corporation plays an important role in aiding buyers and sellers of halon both in the United States and abroad.
The data for estimating the global supplies of halons are collected by two different methods. The first is based on amounts manufactured annually by the major producers and on emission patterns. Countries that have required collection of halon for destruction provide the second. In two such countries, Australia and Germany, the first estimates of the halon to be collected were based on the study of annual production. In both cases, these initial estimates had to be revised downward because the actual quantity of halons collected fell short of projections, possibly because (1) actual quantities within the country were less than estimated, (2) some halon was emitted rather than being collected, or (3) the halon was not turned in. Any or all these could account for the discrepancies. The major point is that we just do not know. Currently, UNEP's Halon Technical Options Committee is reexamining its estimates of the global bank of halons.
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