In the late 1980s concern over the validity of environmental claims led to demands for the creation of schemes that would provide the consumer with verified environmental information. In response, governments and private sector companies developed seal of approval 'ecolabels' purporting to denote the most environment-friendly products in a particular category. However, this book discusses the problem of how it is not possible to acquire sufficient information about the impact of a product over its life cycle to know in every case which product will be the most environment-friendly.