Harmonising indicators for the stakeholder worker in social life cycle assessment

Despite rising knowledge and application of S-LCA in social sustainability assessments, there are still challenges in identifying and implementing indicators that capture social matters. Social indicators are fundamental in S-LCA for being the means by which social impacts are measured. However, the wide profusion of different nomenclatures, definitions, calculation methods, etc., brings S-LCA into a challenging position where practices are still fragmented and, thus, case studies cannot be compared. This work sought to: 1) Analyse and provide a descriptive overview of worker-related indicators applied in S-LCA studies that used primary and secondary data; 2) Examine the adherence of the indicators to the S-LCA framework and ILO standards; and 3) Harmonise these indicators towards a more standardised conceptualization and application. The study encompassed a systematic literature review of case studies on S-LCA that used primary and secondary data indicators, applying a date coverage from 2009 to 2025. In total 219 papers were selected. The mapped indicators were analysed and compared against different criteria to identify similarities, discrepancies, and foundations in international standards, such as the International Labour Organisation's (ILO) and the Guidelines for S-LCA for Products and Organisations. Whenever information was lacking when verifying the indicators' completion or definition in relation to the reference documents, new indicators were proposed and/or better founded. The final list resulted in 149 comprehensive and consistent primary data indicators, and 92 secondary data, across 11 worker's subcategories. The harmonised lists can be applicable across different industries and socioeconomic contexts, supporting comparability and standardisation in S-LCA studies.