|  Lab: Material Performance

The Precautionary List is a compilation of the most ubiquitous and problematic substances that people encounter every day in the built environment. Hosted on the
Transparency website (, it allows design professionals to search for key substances and chemicals of concern using filters like project type, product type, and health and environmental impacts.

The information contained in the site is comprehensive. For each substance featured on the Precautionary List, Perkins+Will provides a repository of current data, including descriptions and overviews, health and environmental hazards, ways in which people can be exposed (“pathways of exposure”), relevant government regulations and industry rating systems, and associated building products.

Perkins+Will has also added a “Watch List” and a “Sunset List.” The Watch List includes substances suspected of being harmful, but where scientific data about their health impacts has only begun to accumulate. (Manufacturers looking to innovate their product formulations are urged to pay special attention to the Watch List.) The Sunset List includes substances previously on the Precautionary List, but now seldom or no longer in use by the industry—for example, the ozone-depleting refrigerants known as chlorofluorocarbons, or CFCs. Asthmagens and flame retardants, which formerly appeared on the site in separate lists, are now incorporated into the Precautionary List.