The National Fire Protection Association (NFPA) is developing new standards on several types of protective clothing. Among these are comprehensive standards for hazardous chemical protective suits, and protective clothing used in emergency medical operations. These standards complement the existing standards published by the NFPA for chemical protective suits. Entailed in the development of each standard is the choice of requirements, methods for measuring material or clothing item performance, and how specific performance levels are established. Each standard, therefore, includes a list of requirements that address the overall performance of the clothing item, material barrier properties to either chemicals or biological agents, material physical properties, and functional or design aspects important to type of clothing being specified. The final selection of these requirements has been based on verification testing on representative products to ensure that the respective requirement simulates the hazard condition and to determine if chosen test methods can accommodate the range of materials products to be tested. Data generated from verification testing is then used to select minimum performance levels when compared to field experience in the use of tested products.