Society of Plastics Engineers – 4spe.org

Vinyl Siding Institute – vinylsiding.org

Uni-bell – www.uni-bell.org

Plastic Pipe & Fitting Association – ppfahome.org

American Architectural Manufacturer’s Association – aamanet.org

American Chemistry Council – americanchemistry.org

American Chemical Society – acs.org

American Society for Testing & Materials – astm.org

Vinyl Institute – vinylinfo.org