ENVIRONMENTAL ASPECTS OF FLUORINATED MATERIALS: PART 3 1 Comparative Life-cycle Assessment of the Impacts Associated with Fire Extinguishants HFC-227ea and IG-541 R. E. BANKS*, E. K. CLARKE**, E. P. JOHNSON** and P. N. SHARRATT² (MEMBER) *Chemistry Department, UMIST, Manchester, UK **Atlantic Consulting, London, UK ²Environmental Technology Centre, UMIST, Manchester, UK F luorinated materials developed to replace materials banned from manufacture under the Montreal Protocol are themselves contributors to environment damage. In particular, their contribution to global warming is under scrutiny from customers, regulators and pressure groups. This paper provides a comparison of the global warming and other impacts associated with two possible replacements for Halon 1301 (a banned ®re extinguishant), namely an `in-kind’ compound CF 3 CHFCF 3 (HFC-227ea) and a `not-in-kind’ blend of nitrogen, argon and carbon dioxide (IG-541). The impacts associated with the manufacture and deployment of the HFC-227ea are found to be substantially greater than those of the inert gas mixture designed for the same ®re-extinguishing duty. The impacts during manufacture reveal an important issue for the widely used measure of global warming impactÐthe so-called Total Equivalent Warming Impact (TEWI). The present work clearly reveals that where impacts associated with manufacture are signi®cant, the scope of the TEWI analysis needs to cover the manufacturing process if it is to be meaningful. Keywords: life-cycle assessment; halon replacements; global warming; TEWI. INTRODUCTION The banning of a range of halogenated materials under the Montreal Protocol has led to substantial activity in the development of replacement materials to carry out the same duties. Broadly, these materials fall into two typesÐ`in- kind’ replacements such as highly ¯uorinated materials, and `not-in-kind’ materials that are not halogenated, such as inert gas mixtures (for ®re-extinguishing) or hydrocarbons (for refrigeration). Not unnaturally, manufacturers, custo- mers, regulatory bodies and environmental pressure groups have an interest in the environmental acceptability of these replacements. In order to meet concerns, there has been much debate on appropriate measures of environmental impact to allow comparison. The TEWI (Total Equivalent Warming Impact) concept was developed under the aegis of AFEAS* and the US Department of Energy to compare the global warming impacts of alternatives to CFCs in refrigeration, air conditioning, insulation (heat transmission barrier) and solvent cleaning applications 2,3 . TEWI is based on the use of global warming potentials (GWPs) referenced to carbon dioxide [GWP CO 2 =1 irrespective of the integration time horizon (ITH)] as reported by the Intergovernmental Panel on Climate Change (IPCC) 4 . The ITH recognizes the fact that different materials have different atmospheric lifetimes, and thus their total contribution to radiative forcing needs to be referred to a given time period. In this study, an ITH of 100 years has been used, as this is the standard generally adopted for policy studies. TEWI has been de®ned by AFEAS 3 as `the sum of the direct (chemical) and indirect (energy) emissions of greenhouse gases from the operation or use of a CFC or ¯uorocarbon system for its useful life’. End-of-life disposal contributionsare included 2 , but it is not clear where the system boundary is (in life cycle terms) and to what extent contributions from the production of a CFC or ¯uorocarbon are considered. We judge the latter situation to be unacceptable, as well illustrated by the results of our recent life-cycle analysis of environmental impacts (green- house warming and ozone depletion) associated with two Halon 1301 (®re extinguishant) replacements. FM-200 TM (based on HFC-227ea, i.e. CF 3 CHFCF 3 ) 5 is a product of Great Lakes Chemical Corporation, USA, and INERGEN Ò (IG-541, a N 2 -Ar-CO 2 blend) 6 is a product of Wormald Ansul UK Ltd. The ®rst object of this paper is to substantiate the above claim by providing details of our evaluation of environ- mental impacts (global warming, stratospheric ozone depletion and qualitative consideration of acid rain) arising from the manufacture of HFC-227ea from common or 229 0957±5820/98/$10.00+0.00  Institution of Chemical Engineers Trans IChemE, Vol 76, Part B, August 1998 * Alternative Fluorocarbons Environmental Acceptability Study, a research programme initiated in 1989 and funded by an international consortium of companies involved in the manufacture of ¯uorocarbons (i.e., halocarbons containing C-F bonds).