How Natural Are the “Natural” Materials? Proposal for a Quali-Quantitative Measurement Index of Naturalness in the Environmental Sustainability Context

Abstract

The overall purpose of the paper is overcoming the misunderstanding of the “naturalness” attribute of materials. This is due to the always-increasing innovative materials considered “environmentally sustainable” and “natural” by producers, material libraries, and designers. The investigated research problem is: how to simply and effectively evaluate the degree of naturalness of a material, preventing a complete and complex LCA analysis? The basic design of the study was focused on (i) creating a multicriteria quali-quantitative method—Material Naturalness Index (MNI)— in order to assess materials’ naturalness scientifically, and (ii) test it by running the evaluation on 60 innovative materials. MNI was set considering the least number of parameters of the Material Life Cycle (i.e., resource kingdom, material resource, material processing, post-use processing). The 60 latest materials selected from the “natural” material family of six international material libraries were selected to test the index. The data analysis was based on the Theory of Attractive Quality, considering attractive, must-be, or reverse qualities. Major findings concerning the index utility were found as a result. MNI was demonstrated to support different actors with different aims: (i) designers, in independently evaluating naturalness of materials using real evidence and pursuing a critical point of view not influenced by marketing claims; (ii) producers, in facing the challenge of naturalness; (iii) material libraries, which are collocated between the two other actors, in proposing measurable information concerning naturalness. In conclusion, the study demonstrated how the key-concept of “naturalness” should be assumed as an attribute rather than as a material family.