Abstract : To address Homeland Security needs for decontamination, the U.S. Environmental Protection Agency (EPA) established an Interagency Agreement with the U.S. Army Edgewood Chemical Biological Center (ECBC) to take advantage of ECBC's extensive expertise and specialized research facilities for the decontamination of surfaces contaminated with chemical and biological (CB) warfare agents. The National Homeland Security Research Center (NHSRC) formed collaboration with ECBC in a mutual leveraging of resources expanding upon ECBC's on-going programs in CB decontamination to more completely address the parameters of particular concern for decontamination of indoor surfaces in buildings following a terrorist attack using CB agents. Vaporized hydrogen peroxide (VHP) and Cl02 are decontamination technologies that have been used to decontaminate indoor surfaces contaminated with anthrax and show potential for use in decontaminating indoor surfaces contaminated by chemical agents. This program is specifically focused on decontamination of the building environment for purposes of restoring a public building to a usable state after a terrorist contamination episode. Since building interiors may contain a large surface composed of concrete cinder block, wood, steel, carpet, ceiling suspension tile, and painted wallboard, the effort was designed to determine how building materials are affected by the decontaminant. The focus of this technical report is the evaluation of the building interior materials and the Steris VHP technology.