Compared to competing materials, steel is by far the material with the lowest CO2 emissions in production when its environmental impact over its entire life cycle is considered. That is why the ecological footprint is documented using defined criteria in environmental product declarations (EPDs), i.e. life cycle assessments for products, and made available to voestalpine customers for environmental assessment.
The voestalpine Group has nothing to hide when it comes to the ecological performance of its products. Instead, it deliberately chooses the path of direct communication. Stefan Schuster from Strategic Environmental Management at voestalpine AG and the Group’s LCA contact, explains: “EPDs are already being requested in tendering processes, for instance in the infrastructure sector. In the area of building certification in particular, there are established systems that make use of the information from the EPDs for the ecological aspect of sustainability. However, we have decided to proactively communicate the environmental aspects of our products and materials and to include them in our arguments.” And steel offers truly convincing arguments.
EPDs have the advantage of being a neutral, objective instrument for communicating information on ecological product evaluation based on defined methods, international standards, and extremely robust data. In addition, the life cycle assessments and results are audited by independent third parties and are publicly available.
For example, voestalpine already holds environmental product declarations for products such as colofer® organically coated steel strips as well as heavy plates and roll-bonded heavy plates. The Group plans to complete work on another EPD for the ‘Rails’ product group in 2018. But how does this work?
Life cycle inventory as basis of EPD
The basis of each such evaluation is the life cycle inventory. All relevant input flows that are included in the relevant production process and all output flows that arise in the process are collected. EPDs are updated every five years to reflect ongoing process changes/improvements. Taking the example of organically coated belts, first the process chain has to be recorded:
- Sintering plant
- Coking plant
- Blast furnace
- Steel plant
- up to coil coating
The product that is created at the end of this process chain is only one part of the output. Emissions, by-products, recycled materials, waste, etc. are also generated in the individual process steps and taken into account in the evaluation. And the flows that are included in the processes are systematically considered, e.g.
- Raw materials
The environmental impacts are systematically determined on the basis of this life cycle inventory and presented as impact indicators. Stefan Schuster explains: “For each process, all relevant input and output flows are determined and the impact indicators, such as global warming potential (carbon footprint), primary energy consumption, acidification potential or water footprint, etc. are calculated. A multitude of indicators are evaluated and presented in the life cycle assessment.”
From cradle to gate
The entire supply chain is covered, of course, says Schuster. “For example, the raw materials, such as the fine ores used in the sintering plant, including mining, transport, and processing, already come with a backpack of environmentally relevant effects. As part of the life cycle assessment, we look at the life cycle of a product ‘from cradle to gate’, i.e. from extraction of the raw materials to the point in time at which the product leaves the factory.”
The positive properties of steel become particularly clear when the entire life cycle is considered—‘from cradle to grave’—i.e. the end of its life. Although steel is used, it can never be used up—it can always be recycled and processed into new steel products. These advantages are clearly shown in a voestalpine EPD: “The EPD demonstrates the environmental benefits of steel compared to other materials.”
To prepare an LCA, a comprehensive life cycle inventory of all relevant input and output flows of the processes under consideration must be drawn up. The environmental impacts are presented using various impact indicators.