What is life cycle assessment?
‘Life Cycle Assessment is a process to evaluate the environmental burdens associated with a product, process or activity by identifying and quantifying energy and materials used and wastes released to the environment; to assess the impact of those energy and material uses and releases to the environment; and to identify and evaluate opportunities to affect environmental improvements.
The assessment includes the entire life cycle of the product, process or activity, encompassing extracting and processing raw materials; manufacturing; transportation and distribution; use, maintenance; recycling and final disposal.’
Life cycle assessment
Life Cycle Assessment (LCA) is defined under ISO 14040, whereby a product’s resource use and emissions are evaluated from cradle-to-gate or cradle-to-grave, and normalised to a functional unit or one square metre of protection of a steel product for a specified period of time.
LCAs can be costly but they have the advantage of making comparisons over a wide range of potential environmental impacts (not just carbon emissions and energy consumption). The disadvantage is that LCA is time consuming, expensive and complex and that the results are often difficult to interpret. For example, practitioners and customers may be left to make their own decisions on the relative importance of higher carbon dioxide emissions for one product and increased ecological toxicity for another.
LCA can allow comparison between products which serve the same purpose, such as coatings for metal products. However, the use of LCA for coatings is relatively new and there are few instances of directly comparable LCA studies in this field with differing functional units, timescales, operating conditions, boundaries and other variables, being used by commercial organisations, university departments and governmental bodies.
Commercial databases which contain Life Cycle Inventories (LCIs) for manufacturing elements and environmental burdens involved in creating a product may be used to build up LCAs. Transmission of researched LCIs is facilitated by EcoSpold, a common data exchange format that links to proprietary LCA software.
It seems sensible to follow the trends currently underway (or planned) for other building products and to calculate the embodied energy and other environmental impacts for galvanized products.
This would allow the galvanized products to be listed alongside, and compared with, alternatives. However, as noted above, the most informative comparisons are between completed structures providing an equivalent service.
The gradual interest from media of the climate debate has put pressure on the development of comparable and quality-assured environmental information. This was identified early by the International Standardisation Organisation, (ISO) which has developed a standard for such information about the environmental performance of products and services, so-called environmental product declarations (EPD®).
