“Guidance for the EPA Halon Emission Reduction Rule (40 CFR Part 82, Subpart H)
The aim of the EPA’ Guidance for Halon Emission Reduction Rule is to ensure that technicians who service halon systems are trained to minimize unnecessary releases of halons, and to maximize their recovery and recycling.
Halons are very effective fire and explosion suppression agents that are electrically non-conductive and leave no residue. As such, they are extremely valuable for certain applications. The halons covered by 40 CFR Part 82, Subpart H are Halon 1211 (CF2ClBr), Halon 1301 (CF3Br), and Halon 2402 (C2F4Br2).
The halons covered by 40 CFR Part 82, Subpart H contain the chemical element bromine (Br) and also, in the case of Halon 1211, chlorine (Cl). Br and Cl both contribute to stratospheric ozone destruction.
The earth's stratosphere is a layer of the atmosphere that begins between 5 and 11 miles above the earth’s surface and extends up to about 30 miles above the earth’s surface. Ninety percent of the ozone in the earth’s atmosphere is found in the stratosphere. The characteristics of halon and other human-made chemicals that can deplete ozone (e.g., chlorofluorocarbons, or CFCs) enable them to reach the stratosphere, where they break down and the Cl and Br from them can destroy ozone. Halons are a major source of bromine in the stratosphere.
Stratospheric ozone destruction is a human health risk:
Ozone in the earth’s stratosphere protects the earth from the penetration of harmful ultraviolet (primarily UV-B) solar radiation by absorbing most of this harmful UV-B, allowing only a small amount to reach the earth’s surface. Without the filtering action of the ozone layer, more of the Sun’s UV-B radiation would penetrate the atmosphere and reach the earth’s surface.
Increased UV-B radiation can lead to increased incidence of certain skin cancers and cataracts, as well as other human health and environmental consequences.
There is a limited supply of halon:
Due to concerns about stratospheric ozone layer destruction, many countries have, under the landmark international agreement known as the “Montreal Protocol on Substances that Deplete the Ozone Layer,” ended or plan to end production of ozone-depleting substances. The Montreal Protocol was first negotiated in 1987 and now involves more than 162 countries. In the United States, halon production ended in 1994, and recycled halon and inventories produced before January 1, 1994, are now the only sources of supply.
References 5 and 8 in Appendix B describe U.S. government and industry programs that were developed in response to the ban on halon production to store (“bank”) and trade halon.
There are alternative agents for most current halon applications:
EPA has, under its Significant New Alternatives Policy (SNAP) program, listed several acceptable alternative agents and technologies for halon total-flooding and streaming applications. The SNAP program goal is to ensure that industry and consumers have ample alternatives to applications for which ozone-depleting substances, including halons, are currently used; and that these alternatives reduce the overall risk to human health and the environment.
References 14, 15, 18, 26 and 27, and Web site 1 in Appendix B describe halon alternatives and EPA’s SNAP program.”
