with an iodine atom. CF3I has similar fire-suppression potential (Tapscott 1999; Chaney 2002) but much lower ozone-depletion potential—0.008-0.01 compared with 12 for Halon 1301 (Solomon et al. 1994; Connell et al. 1996; Bannister et al. 2003). The cited inerting1 concentration of CF3I is 6.5% (NFPA 2000). CF3I breaks down in the presence of sunlight and degrades rapidly at temperatures above 100°C, producing hazardous by-products that include hydrogen fluoride (HF), hydrogen iodide (HI), and carbonyl fluoride (COF2) (McCain and Macko 1999). Exposure to those decomposition products should be considered in the assessment of health effects of use of CF3I. Orion Safety Industries (2000) has discussed one of the decomposition products, HF, and suggests that concentrations of HF produced by degradation of CF3I are similar to those produced by degradation of Halon 1301.


The 1999 Army review of CF3I concludes that it should not be used “in many Army systems without further evaluation” (McCain and Macko 1999). The 2002 update (Chaney 2002) concludes that CF3I can be used in normally unoccupied areas only and that “any employee that could possibly be in the area must be able to escape within 30 sec, and the employer must ensure that no unprotected employees enter the area during agent discharge.” Those conclusions are based on the U.S. Environmental Protection Agency (EPA) Significant New Alternatives Policy guidelines (60 Fed. Reg. 31092 [1995]).

A presentation on potential military uses of CF3I was given to the present National Research Council subcommittee by J. Vitali, of Georgia Tech Research Institute (Vitali 2003). The presentation also discussed approved uses in countries other than the United States. Suggested potential uses include many Army systems that now use Halon 1301, such as

  1. Fire suppression in helicopter engines.

  2. Ground vehicle engine compartments, for example, armored personnel carriers.

Halon 1301 can be used in occupied and unoccupied spaces; however,


An inerting gas usually refers to a gaseous mixture containing little or no oxygen and mainly consisting of non-reactive gases or gases having a high threshold before they react. Nitrogen, argon, and carbon dioxide are common examples.

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