heard about the purpose, feasibility, and capability of prior and current building protection schemes from representatives of various agencies and contractors involved in building protection programs and test beds. Based on these briefings, other documents, committee deliberations, and the committee’s collective expertise, this report highlights basic principles and lays out the variables and options to consider in designing and implementing building protection against biological and chemical threats.


Appropriate design and implementation of building protection is determined by multiple factors, including (1) threat types; (2) activities housed within the building and the mission of those activities; (3) the level of protection sought; (4) limitations posed by procurement type, quality of design and construction, maintenance, and wear and tear of the building; and (5) availability of resources.

Threat Types and Threat Agents

This report addresses two threat types: airborne releases of biological threat agents and airborne releases of chemical threat agents. “Threat agent” refers to the biological or chemical agent used in an attack. Biological threat agents considered here include bacteria (vegetative and spores), viruses, and products of organisms (toxins). Chemical agents considered here include those that can be dispersed as droplets or vapors. Because of the wide variety of biological and chemical agents, their symptomatic progressions, and associated fatality rates, the committee concluded that the best classification of threat agents is according to the two most critical properties related to current vulnerabilities in building protection—the ease of timely detection and the ease of timely treatment (see Figure S-1). This classification treats biological and chemical threats equally and addresses vulnerabilities from unknown threats. The ability to detect agents ranges from agents that are visible to the naked eye to those that are difficult or impossible to detect at levels of concern even with sophisticated equipment (see Figure S-1). The time window for treatment likewise varies from several days for threat agents that have long incubation or latent periods (slow-acting) to minutes for threat agents that produce rapid onset of illness or even death (fast-acting). Protection from difficult-to-detect and fast-acting threat agents is obviously the most challenging building protection scenario.

Activities and Mission

Buildings are constructed for different purposes and have different activities occurring within them. The need for protection varies among structures based

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