The Mediating Role of Green Supply Chain Management and Green Innovation in the Impact of Green HRM on Sustainable Performance: A Case Study of the Food Industry in Karaj

Introduction
Driven by the growing global imperative to address manufacturing-related environmental degradation, organizations are increasingly compelled to integrate sustainable practices to safeguard public health and well-being. While sustainability has emerged as a critical pillar of modern management, firms frequently grapple with the complex environmental and social pressures that necessitate a fundamental overhaul of traditional practices. In this landscape, Green Human Resource Management (GHRM) and Green Innovation have surfaced as pivotal strategies for achieving sustainability goals; the former optimizes human capital through eco-conscious policies, while the latter leverages advanced technologies to minimize resource consumption and waste. Despite their potential, the literature remains divided on the direct impact of these initiatives on organizational performance—a disparity largely attributed to implementation hurdles such as prohibitive costs, systemic resistance, and the need for significant structural change. Furthermore, the critical role of Green Supply Chain Management—which integrates supply, production, and distribution processes toward sustainable outcomes—remains under-researched. Consequently, a gap exists in understanding the synergistic interplay between GHRM, Green Innovation, and green supply chains, particularly regarding their simultaneous influence on the triple bottom line of sustainability. To address this void, this study investigates the impact of GHRM on sustainable performance within the food industry in Karaj, uniquely positioning Green Supply Chain Management and Green Innovation as essential mediators in this framework.
 
Methodology
This study is applied in purpose, cross-sectional in time, and adopts an ex post facto (causal–correlational) research design. Data were collected using a survey method, and the variables were examined through a quantitative approach. The statistical population comprised managers and experts with knowledge of supply chain management and human resource management in food industry companies located in Karaj. Convenience sampling was employed, and questionnaires were distributed among employees, specialists, and managers with more than three years of work experience in these companies. According to a report from the Industry and Mining Organization, there are 153 food industry companies operating in Karaj. Based on the requirements of the Partial Least Squares (PLS) approach, the minimum sample size was estimated at 40 respondents; however, a total of 132 valid questionnaires were ultimately collected and analyzed. Data analysis and hypothesis testing were conducted using SPSS software and Structural Equation Modeling (SEM) based on the PLS technique.
 
Findings
The results of the hypothesis testing indicate that Green Human Resource Management (GHRM) does not have a significant direct effect on sustainable performance, and the mediating role of Green Innovation (GI) in this relationship is also not supported. However, the relationship between GHRM and sustainable performance becomes significant when mediated by Green Supply Chain Management (GSCM). When both GSCM and GI are simultaneously considered as mediators, no significant effect is observed. In addition, the hypothesis proposing that GSCM influences sustainable performance through the mediation of GI is not supported. The findings further reveal that GHRM has a significant positive effect on GI, and this relationship is strengthened when GSCM is included as a mediator. Overall, the results show that most of the proposed hypotheses are supported, except for those related to the effect of GI on sustainable performance and the hypotheses in which GI and GSCM are considered together as mediating variables.
 
Discussion and Conclusion
The findings of this study suggest that Green Human Resource Management (GHRM) and green innovation, when implemented independently, may not contribute positively to sustainable organizational performance, and green innovation does not function effectively as a mediator between GHRM and sustainable performance. The absence of a significant relationship between GHRM and sustainable performance may stem from the misalignment of HR strategies with sustainability objectives, limited and ineffective green HR practices, inadequate evaluation mechanisms to identify and address weaknesses, employee resistance to change, and the insufficiency of relying solely on HR-related initiatives without integrating other organizational approaches. Likewise, the lack of a significant effect of green innovation—both as an independent variable and as a mediator—may be attributed to the narrow focus on only two dimensions: green product innovation and green process innovation. In practice, green innovation also encompasses managerial and market-related aspects, which can enhance sustainability across multiple dimensions; however, these aspects were not examined in the present study. In contrast, Green Supply Chain Management (GSCM) appears to play a crucial role in the successful implementation of green policies within organizations and in mitigating the negative effects associated with GHRM. The results indicate that an integrated green supply chain can offset the negative impacts of GHRM on sustainable performance and potentially transform them into positive outcomes. This underscores the importance of coordination and integration across all supply chain activities to achieve sustainability goals. Accordingly, managers should recognize that focusing solely on greening HR practices, without simultaneously implementing green supply chain strategies, may not yield the desired sustainability outcomes. Instead, establishing an integrated and environmentally responsible supply chain that incorporates multiple dimensions of sustainability can significantly enhance sustainable performance. Furthermore, the results reveal that when green innovation is introduced alongside GSCM as a mediator, the relationship loses significance, suggesting that limiting green innovation to product and process dimensions may create structural weaknesses within organizations. Overall, the study highlights the need for organizations to adopt a comprehensive and coordinated approach—centered on green supply chain management rather than isolated GHRM initiatives or narrowly defined green innovations—to achieve more effective and sustainable organizational performance.