Effect of Bromine Substitution on the Lifetimes and Ozone Depletion Potentials of Organic Compounds.
Effect of Bromine Substitution on the Lifetimes and
Ozone Depletion Potentials of Organic Compounds.
Huie, R. E.; Orkin, V. L.; Louis, F. L.; Kozlov, S. N.;
Kurylo, M. J.
NIST SP 984; June 2002.
Halon Options Technical Working Conference, 12th.
Proceedings. HOTWC 2002. April 30-May 2, 2002,
Albuquerque, NM, Gann, R. G.; Reneke, P. A.,
Editor(s)(s), 1-9 pp, 2002.
Available from:Both the presentations and the papers are available on
the HOTWC web site:
halons; halon alternatives; bromine; ozone
Although the bromofluorocarbon compounds known as halons
are excellent fire suppressants, their production is
being phased out due to the considerable danger they
pose to the Earth's ozone layer. A number of
non-brominated substances have been proposed and tested,
but the effort to find replacements continues to return
to bromine due to the chemical characteristics of this
element as a chemically active flame suppressant. Thus,
a number of classes of brominecontaining molecules have
been proposed for investigation as to their
fire-suppression characteristics. Before candidate
replacements can be placed into service, it is important
to establish their environmental effects, particularly
the projected ozone depletion potential. Generally,
these replacement compounds are designed to be reactive
toward atmospheric hydroxyl radicals. This reaction
leads to chemical transformations that ultimately lead
to the removal of the bromine from the atmosphere.
Additionally, photolysis of these compounds in the
atmosphere will release Br and may further shorten their
lifetimes. In order to quantitatively evaluate the
impact of these compounds in the atmosphere, we have
investigated the reactivity of several classes of
reactants toward OH, both experimentally and
computationally. Rate constants were determined over the
temperature range of at least 250 K to 370 K. In
addition, we have measured the absorption spectra of
most of these compounds down to 160 nm. We have then
utilized this information to derive predicted ozone