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Photodegradation of CF3I (NIST SP 890)



Marc R. Nyden


CF3I has been identified as a leading candidate for the replacement of halon fire extinguishing agents because of its high degree of effectiveness as a flame suppressant and its short tropospheric lifetime and low ozone depeletion potential. Although this compound is known to undergo rapid photolysis in the presence of sunlight, the byproducts of the photodegradation process have not been determined. It is also not known whether this agent will photolyze significantly when it is exposed to radiation from fluorescent lamps and other common sources of indoor light. This knowledge is essential to assess the stability of this agent and the risk of human exposure to it and its byproducts. The spectrum of a fluorescent lamp, obtained in this laboratory, indicates a measurable radiative flux out to about 310 nm. The observation that this spectrum overlaps with the absorption spectrum of CF3I suggests that this agent should undergo appreciable photolysis when it is exposed to radiation from fluorescent lights. The objectives of this study are to determine the extent of this degradation and the nature of the compounds which are likely to be produced when CF2I is released in an indoor environment.
Special Publication (NIST SP) - 890
Report Number


fire suppression, aircraft engines, nacelle fires, simulation, experiments, degradation, decomposition, halon 1301, halon alternatives, lamps, photolysis


Nyden, M. (1995), Photodegradation of CF3I (NIST SP 890), Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed May 21, 2024)


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Created November 1, 1995, Updated February 19, 2017