It has been 50 years since Rachel Carson published Silent Spring. I recently took the time to read Carson’s seminal work (available through iTunes here), which outlines the environmental and human health costs of using pesticides, insecticides, and other chemical applications, and was struck by the relevance of the message.
The green building movement is approaching a crossroads with the building product industry. A vast range of materials ranging from polyvinyl chloride (PVC) based products, to mercury thermometers, lead solders and roofing materials, and certain paints and finishes release PBT’s (or Persistent Bioaccumulative and Toxic chemicals). Similar to the various chlorinated hydrocarbon based chemical treatments that Carson warned us about half a century ago, the PBTs released through the manufacture and/or application of certain building materials do not readily break down from natural processes. The chemicals also accumulate in fatty tissues concentrating as they move up the food chain and are often highly toxic even in small quantities.
As a result of the environmental and human health threat posted by such chemicals, various environmental health advocates have prioritized substitution away from materials associated with the release of PBTs.
Unfortunately for design and construction professionals, there are several concurrent efforts underway by numerous organizations – each with their own short list of building materials and/or chemicals that should be avoided whenever possible. These lists, commonly refereed to as Red Lists, are increasingly being referenced by project specifications, green building certification programs, and design standards.