Assessing the social impacts of nano-enabled products through the life cycle: the case of nano-enabled biocidal paint

Purpose: Assessment of the social aspects of sustainability of products is a topic of significant interest to companies, and several methodologies have been proposed in the recent years. The significant environmental health and safety concerns about nano-enabled products calls for the early establishment of a clear benefit-risk framework in order to decide which novel products should be developed further. This paper proposes a method to assess the social impacts of nano-enabled products through the life cycle that is (a) quantitative, (b) integrates performance and attitudinal dimensions of social impacts and (c) considers the overall and stakeholder balance of benefits and costs. Social life cycle assessment (s-LCA) and multi-criteria decision analysis (MCDA) are integrated to address this need, and the method is illustrated on a case study of a nano-enabled product. Methods: The s-LCA framework comprises 15 indicators to characterize the social context of the product manufacture placed within the classification structure of benefit/cost and worker/community. The methodology includes four steps: (a) normalization of company level data on the social indicator to country level data for the year, (b) nested weighting at stakeholder and indicator level and its integration with normalized scores to create social indicator scores, (c) aggregation of social indicator scores into benefit score, cost score and net benefit scores as per the s-LCA framework and (d) classification of social indicator scores and aggregated scores as low/medium/high based on benchmarks created using employment and value-added proxies. Results and discussion: A prospective production scenario involving novel product, a nano-copper oxide (n-CuO)-based paint with biocidal functionality, is assessed with respect to its social impacts. The method was applied to 12 indicators at the company level. Classification of social indicator scores and aggregated scores showed that the n-CuO paint has high net benefits. Conclusions: The framework and method offer a flexible structure that can be revised and extended as more knowledge and data on social impacts of nano-enabled products becomes available. The proposed method is being implemented in the social impact assessment sub-module of the SUN Decision Support (SUNDS) software system. Companies seeking to improve the social footprint of their products can also use the proposed method to consider relevant social impacts to achieve this goal.