After the terrorist attacks of September 11, 2001 and the anthrax attacks in the fall of 2001, federal and state personnel provided response, recovery, and remediation under trying circumstances, including unprecedented demand on their capabilities to analyze environmental samples. In reviewing these events, the Environmental Protection Agency (EPA) identified several areas where the country could better prepare itself in the event of future terrorist incidents. The need to improve the nations laboratory capacity and capability to analyze environmental samples following a homeland security event (i.e., chemical, biological, and/or radiological (CBR) crime/attack) was one of the most important areas identified. In response, EPA formed the Homeland Security Laboratory Capacity Work Group to identify and implement opportunities for near-term improvements and to develop recommendations for addressing longer-term laboratory issues. The EPA Homeland Security Laboratory Capacity Work Group consists of representatives from the Office of Research and Development (ORD), Office of Air and Radiation (OAR), Office of Water (OW), Office of Solid Waste and Emergency Response (OSWER), Office of Environmental Information, Office of Chemical Safety and Pollution Prevention, and several EPA regional offices. A critical area identified by the work group was the need for a list of analytical methods to be used by all laboratories when analyzing homeland security event samples and, in particular, when analysis of many samples is required over a short period of time. Having standardized methods would reduce confusion, permit sharing of sample load between laboratories, improve data comparability, and simplify the task of outsourcing analytical support to the commercial laboratory sector. Standardized methods would also improve the follow-up activities of validating results, evaluating data, and making decisions. To this end, work group members formed an Analytical Methods Subteam to address homeland security methods issues.