- After reviewing research, development, toxicology, and engineering activities directed toward finding alternative and replacement agents for halon 1301 and halon 1211, the committee finds that in this context, the relevant aspects of the problem are being studied effectively and a comprehensive body of scientific and engineering knowledge is being developed, and the committee has identified no obvious gaps in these important efforts.
- It is unlikely that a drop-in replacement agent will be discovered that will exhibit all of the beneficial properties of halon 1301 and not also exhibit a significant environmental impact.
- Effective alternative chemical agents have been identified by the Navy and are currently being incorporated into the design of new ships and aircraft. There is a weight and volume penalty associated with these agents relative to halons, but the impact can be minimized if use of these agents is incorporated into initial platform design. Further, retrofit of these agents into existing naval platforms is technically feasible in most cases.
- In addition to the chemical replacement agents, promising alternative fire extinguishing systems such as water mist systems and inert gas generators are under consideration by the Navy for some applications. These systems are being incorporated into new-design naval platforms.
Contents of This Report
This study addresses various science and engineering aspects of the agents and methods that are being considered as substitutes for halons and halon systems used as fire suppressants by the U.S. Navy in ships and aircraft. Chapter 1 points out the Navy's ongoing need for effective fire suppression and outlines the set of extensive requirements that candidate replacements for halons must satisfy. Chapter 2 describes research on flames, mechanisms of flame suppression, methodology of agent evaluation including suppression efficiency and toxicology, manufacturability, and aspects of the search for alternative agents. Atmospheric chemistry phenomena relating to an alternative agent's capacity to deplete ozone, contribute to global warming, or give rise to surface pollution through the accumulation of noxious reaction products are covered in Chapter 3. Chapter 4 describes Navy-specific aspects of halon replacement in ships and aircraft, suggests possible courses of action, and provides the committee's preferred alternative. The appendixes give details as appropriate.