The National Institute of Justice is the focal point for providing support to state and local law enforcement agencies in the development of counterterrorism technology and standards, including technological needs for chemical and biological defense. In recognizing the needs of state and local emergency first responders, the National Institute of Standards and Technology, working with the National Institute of Justice, the Technical Support Working Group, the U.S. Army Soldier and Biological Chemical Command, and the Interagency Board, is developing chemical and biological defense equipment guides. The guides will focus on chemical and biological equipment in areas of detection, personal protection, decontamination, medical, and communication. This document focuses specifically on chemical detection equipment for chemical agents and toxic industrial materials and was developed to assist the emergency first responder community in the evaluation and purchase of chemical detection equipment. The long range plans are to: (1) subject existing chemical detection equipment to laboratory testing and evaluation against a specified protocol, and (2) conduct research leading to the development of a series of documents, including national standards, user guides, and technical reports. It is anticipated that the testing, evaluation, and research processes will take several years to complete; therefore, the National Institute of Justice has developed this initial guide for the emergency first responder community in order to facilitate their evaluation and purchase of chemical detection equipment. In conjunction with this program, additional guides, as well as other documents, are being issued in the areas of biological agent detection equipment, decontamination equipment, personal protective equipment, medical kits and equipment, and communications equipment used in conjunction with protective clothing and respiratory equipment.