This handbook was developed to help companies embed environmental considerations into their mineral supply chain due diligence procedures. The handbook builds on the leading international, government-backed standards on supply chain due diligence and responsible business conduct: the OECD Guidelines for Multinational Enterprises on Responsible Business Conduct, the OECD Due Diligence Guidance for Responsible Supply Chains of Minerals from Conflict-Affected and High-Risk Areas and the OECD Due Diligence Guidance for Responsible Business Conduct. This handbook demonstrates how OECD instruments on due diligence can be applied to address environmental risks and impacts in mineral supply chains by contextualising existing recommendations and directing users towards useful resources.