The LCA methodology is described in the internationally accepted EN-ISO 14040 series, accredited by the European Committee for Standardisation (CEN). These standards reflect the state of the art methodology of the LCA which is generally accepted amongst the LCA practitioners.
As a result, any LCA study, especially those commissioned for legislative purposes, has to be performed according to these standards.
- ISO 14040:2006, Environmental management - Life cycle assessment - Principles and framework, provides a clear overview of the practice, applications and limitations of LCA to a broad range of potential users and stakeholders, including those with a limited knowledge of life cycle assessment.
- ISO 14044:2006, Environmental management - Life cycle assessment - Requirements and guidelines, is designed for the preparation of, conduct of, and critical review of, life cycle inventory analysis. It also provides guidance on the impact assessment phase of LCA and on the interpretation of LCA results, as well as the nature and quality of the data collected.
- ISO 14040:2006 and ISO 14044:2006 replace the previous standards (ISO 14040:1997, ISO 14041:1999, ISO 14042:2000 and ISO 14043:2000). The new editions have been updated to improve the readability, while leaving the requirements and technical content unaffected, except for errors and inconsistencies.
- ISO/TR 14047:2003 provides examples to illustrate current practice in carrying out a life cycle impact assessment in accordance with ISO 14042. These are only examples of the total possible "ways" to satisfy the provisions of ISO 14042. They reflect the key elements of the life cycle impact assessment (LCIA) phase of the LCA.
- ISO/TS 14048:2002 provides the requirements and a structure for a data documentation format, to be used for transparent and unambiguous documentation and exchange of Life Cycle Assessment (LCA) and Life Cycle Inventory (LCI) data, thus permitting consistent documentation of data, reporting of data collection, data calculation and data quality, by specifying and structuring relevant information.
Many guidelines are available to help undertake LCA in different parts of the world, or for different product types.
One of the most important guidelines has recently been by the Institute for Environment and Sustainability in the European
Commission Joint Research Centre (JRC), in co-operation with the
Environment DG: International Reference Life Cycle Data System (ILCD) Handbook "Recommendations based on existing environmental impact assessment models and factors for Life Cycle Assessment in a European context"
The ILCD handbook is part of the Commission's promotion of sustainable consumption and production patterns. The ILCD Handbook is in line with international standards and has been established through a series of extensive public and stakeholder consultations.
ILCD handbook structure
The ILCD handbook consists of a set of documents that are in line with the international standards on LCA (ISO 14040/44):
- The General guide for Life Cycle Assessment consists of both a comprehensive, detailed guide as well as a "cook-book"-style guide for experienced LCA practitioners. It covers all aspects of conducting an LCA: defining the objective and target audience, gathering data on resource consumption and emissions that can be attributed to a specific product, calculating the contribution to impacts on the environment, checking the robustness and significance of results and conclusions, and reporting and reviewing to ensure transparency and quality.
- The Specific guide for Life Cycle Inventory (LCI) data sets builds on the general guide. It provides more detail for the generation of specific types of data. For example, it describes how to create LCI data sets that best reflect the average situation regarding emissions and resource consumption.
- The Life Cycle Impact Assessment (LCIA) guide provides requirements for assessing the emissions and resource consumption associated with a product in terms of impacts on the environment, human health, and resources depletion. It outlines criteria against which models and indicators for use in LCIA should be evaluated, covering both scientific aspects and stakeholder acceptability.
- The guide on Review schemes for Life Cycle Assessment presents the minimum requirements for review for life cycle data or assessments for different applications. The guide on Reviewer qualification specifies the requirements on the experiences and expertise of reviewers.