A growing concern for the emergency preparedness community is biological and chemical terrorism. While HCFs are an essential component of the emergency response system, they are poorly prepared for such incidents at present. The sudden presentation of large numbers of contaminated individuals represents the greatest challenge for HCFs. Guidelines for managing contaminated patients have been based on traditional hazardous material response or military experience, neither of which is directly applicable to the civilian HCF. The key elements of an effective HCF response plan include prompt recognition of the incident, staff and facility protection, patient decontamination and triage, medical therapy, and coordination with external emergency response and public health agencies. Controversial aspects include the choice of personal protective equipment, establishment of patient decontamination procedures, the role of chemical and biological agent detectors, and potential environmental impacts on water treatment systems. Questions that remain unanswered involve equipment and training requirements and the ideal avenues through which HCFs can disseminate information during an event. The time has come to establish a forum of experts to address the questions presented here and to reach a consensus on how to develop and disseminate comprehensive guidelines for HCFs. These solutions should be fully integrated into the community response plan for chemical and biological terrorism. 1 figure and 78 references.