Life cycle assessment (LCA) has become a critically important tool for guiding product design and environmental policy, but methodological efforts in LCA have focused predominantly on data gathering, while less emphasis has been placed on data interpretation. Life Cycle Impact Assessment (LCIA) is composed of characterization, normalization, and weighting, and there are several impact assessment methods available to LCA analysts that apply to any life cycle inventory, each with different characterization factors, impact categories, and normalization references. For example, TRACI, IMPACT+ 2002, CML and ReCiPe provide alternative methods of making meaning from the myriad and disparate chemical releases that are reported in a life cycle inventory. While prior studies find that the recommendations of an LCA can change depending on the choice of impact assessment method, none of the prior comparative LCIA methodological studies have isolated the question of sensitivity of results to normalization. (Zhou et al 2011, Dreyer et al 2003, Cavalett et al 2012).