Look for materials with Health Product Declarations and Environmental Product Declarations. Consider requiring either HPD's or EPD's in specifications.
HPD Collaborative Lists materials that have Health Product Declarations. Products that have HPDs let you the ingredients of a product, and their impact on human health.
UL Environment Sustainable Product Guide Lists materials that have Environmental Product Declarations and other certifications provided by UL Environment such as Greenguard. UL is the same body that certifies appliances for electrical safety.
Perkins+Will Precautionary List Perkins+WIll developed their precautionary list as a tool to identify and avoid potentially hazardous ingredients.
Cradle to Cradle: Cradle to Cradle is a certification originally developed by McDonough and Braungart to recognize products that are made with materials that have closed loop life cycles. That is, the material can be recycled into a new product, or it can return to the earth without any negative environmental impacts (biodegradable for example). Their website lists a range of products that hold C2C certification.
GreenWizard: software that offers a set of tools to empower design help streamline the green building projects.
Pharos Project: A tool for users to locate the best materials to meet their current needs and enduring values in order to create transparency in the building materials market.
Whole-Building Life Cycle Assessment
Athena Impact Estimator: evaluates whole buildings and assemblies based on internationally recognized life cycle assessment methodology.
Tally (Revit Plugin): Revit application that allows architects and engineers to quantify the environmental impact of building materials for whole building analysis and comparative analysis.