There is growing interest in the assessment of products from a life cycle perspective. Product life cycles are often dominated by extensive chemical supply chains that lead up to the materials contained in the products and the overwhelming contribution that the production of these chemicals make to the overall life cycle due to their energy intensity. This book has three specific objectives. The first is to develop a systematic methodology to optimize material selections for a product based on life cycle inventory characteristics. The second is to use this methodology combined with sustainability assessment standards to assess whether these standards are congruent with life cycle assessment. The third is to develop an approach to design product sustainability assessment standards that are clear and consistent with life cycle principles.