Chemical, biological, and radioactive (CBR) threats are generally only recognized after a catastrophic event such as terrorism or sabotage occurs. However, many buildings and facilities throughout the world already have these known risk factors. This resource aids building owners and operators in quickly determining appropriate risk management both during normal operations and when emergencies occur. It explores ventilation systems, the value of sheltering versus evacuation, design options, decontamination methods, and mechanical systems. It also presents summaries of regulations that are used to determine if chemicals that are present create a risk to off-site locations or constitute a homeland security vulnerability.