The long-term durability provided by galvanizing is achieved at relatively low environmental burden in terms of energy and other globally relevant impacts, especially when compared to the energy value of the steel it is protecting.
Attention to durability of steel structures and components has important environmental, economic and social consequences. Some of these are less obvious than others.
The overall economic cost of corrosion has been studied in several countries. It is commonly estimated at up to 4% of gross domestic product.
Several studies have demonstrated the high economic and environmental costs associated with the repeated maintenance painting of steel structures. These burdens can be significantly reduced by an initial investment in long-term protection.
Lack of attention to optimal corrosion protection can leave a damaging economic legacy of repeated maintenance costs. In social housing projects, future maintenance costs will be borne by the local authorities. In public infrastructure projects, use of galvanized steel leads to lower maintenance budgets, releasing public funds for other purposes.
In 2016, EGGA completed an extensive Life Cycle Inventory (LCI) study to determine average environmental burdens required to give lifetime protection for steel products. The study was carried out by Life Cycle Engineering srl (Italy) and collected detailed environmental information from 66 galvanizing plants producing over 1 million tonnes of coated steelwork in 14 countries. LCE worked closely with EGGA’s national associations to collate the sample. The sample was then carefully checked to be representative of the mix of technology used across the industry. The LCI data are fully comprehensive – covering every aspect of the galvanizing process, from raw materials to process energy and ancillary operations. EGGA’s LCI data is available, on request, to LCA professionals who are engaged in relevant life cycle studies for galvanized products.
The EPD has been generated under the International EPD System® and is verified in accordance with ISO 14025:2010 and EN 15804.
Batch galvanizing is most often specified early in the design of steel components and structures with the coating application being sub-contracted much later in the supply process. For this reason, a sector-based EPD is the most informative approach for architects and designers when considering environmental information. Environmental burdens of the galvanized coating are separated from that of the steel plate – to demonstrate that the additional burden of providing lifelong protection for steel components is extremely small.
EGGA has collaborated with Professor Tom Woolley – a well-known architect and environmental researcher – to publish ‘Galvanizing and Sustainable Construction: A Specifiers Guide’. This comprehensive book explains the economic, social and environmental aspects of batch galvanizing in the context of sustainable building. The publication is also available in other European languages.
Articles and Useful Documents
‘Life cycle studies show galvanized steel lighting columns have best environmental credentials’, Gert-Jan Vroege, Search Consultancy B.V., the Netherlands, Hot Dip Galvanizing magazine, Issue 03/2014
‘A Life Cycle Approach to Comparing Galvanized Steel with Aluminium for Lighting Poles’, Jan Vroege, Search Consultancy B.V., the Netherlands, EGGA Assembly 2014
‘Hot Dip Galvanizing Takes LEED with Recycled Content’, American Galvanizers Association, 2011
‘Zinc – A Sustainable Material, Essential for Modern Life’, International Zinc Association
‘Zinc Recycling – Material Supply’, International Zinc Association