Contemporary research on corporate social responsibility (CSR) highlights its disputed effect on firm profitability and the determinants of environmental disclosure. Largely missing from these accounts is a critical look at stakeholders — particularly agents in the public, market, and voluntary sectors — and how they influence corporate investment in environmental management systems (EMS). This study explores CSR trends in Taiwan’s private-sector steel industry, focusing on small- and medium-sized enterprises (SMEs) with electric arc furnaces and contrasting them with the nation’s flagship industry conglomerate, China Steel. The research suggests that without a crisis of legitimacy or significant stakeholder pressure — particularly government pressure and pressure to retain ISO 14000 certification — SMEs see little incentive (and high costs) to build an effective EMS. Also, contextual factors in Taiwan pose both problems and opportunities for sustainable initiatives. Specifically, environmental laws are modern and strict, but administrative capacity to implement laws is not uniform island-wide. Also, activists and localized self-help groups pay less attention to SME steel firms and spend more effort over controversial industries like nuclear power, high-tech manufacturers and petrochemical companies. Still, government and cross-sector alliances sometimes take an active role in subsidizing EMS and promoting research and development. Using a mixed methods approach within the critical field of political ecology, the research concludes that economic concerns drive SME steel firm behavior, with changes in the scale of EMS development coming into play only in favorable cost-benefit scenarios and typically with substantial pressure emanating from the private and public sectors.