We shall also see that the ambiguity and uncertainty of LCA results and the difficulty of communicating them in a meaningful way have led to a flurry of tools and approaches either to simplify or to standardise the assessment. This approach requires the standardisation of data and impact assessment methods. The results of LCA studies can then be communicated through Environmental Product Declarations (EPD) or more simplified models such as life cycle-based ecolabels. The publication Global Guidance Principles for Life Cycle Assessment Databases4 has made a very important contribution to consensus building on how to collect data and manage databases in a consistent way.