Precision of a Streamlined Life Cycle Assessment Approach Used in Eco-Rating of Mobile Phones

Abstract

There is a lack of prescribed databases and approaches in place for performing comparable Life Cycle Assessments (LCAs) of smartphones and other electronic devices in a coherent manner. Hence there is a need within certain eco-rating initiatives for simplified, yet still precise enough, approaches that are expert independent. Here, five independently published Full LCAs (FLCA) of smartphones—and a metal content declaration of a tablet—are analyzed and compared with the simplified LCA method (Open Eco Rating LCA, OLCA) used by the open eco rating (OER) sustainability assessment. OLCA is described in detail. The comparisons use the same characterization factors that are used for climate change and abiotic resource depletion (ARD) midpoint impact categories. The tablet is only analyzed for the ARD indicator (ARDI). The results show that the difference between the FLCAs and the OLCA is up to 20% for the Global Warming Potential indicator (GWPI). The difference is explained by significantly different emission intensities used in FLCAs and OLCA, especially for integrated circuit and screen production. The life cycle use of metals relevant for ARDI is identified in one of the FLCAs of mobile phones, and used in OLCA and compared with the corresponding FLCA ARDI score. The total FLCA ARDI score is 67% (2.0 vs. 1.2 grams Sb—eq.) and 32% (4.98 vs. 3.76 grams Sb—eq.) higher than OLCA ARDI for the mobile phone and the tablet, respectively. The reason is that OLCA only captures a few of the most relevant metals (gold, silver, tin, indium, and tantalum) for the ARDI. However, cobalt—and to some degree copper and lithium—are significant gaps in the OLCA. The conclusion is that OLCA is an efficient and fair approach for LCAs that are focused on the GWPI of smartphones as the divergence to FLCA can easily be explained. However, the circular footprint formulae, renewable electricity options, and ARD characterization indices for cobalt, copper and lithium should be added to OLCA for further precision. The next step is to compare the Product Environmental Footprint (PEF) FLCA method with OLCA for GWPI and ARDI evaluations of new smartphones. Moreover, the effect of adding more midpoint or single score indicators could be tested in OLCA.