The new National Institute of Justice, Chemical, Biological, Radiological, or Nuclear (CBRN) Protective Ensemble Standard for Law Enforcement, NIJ Standard 0116.00 was developed by representatives from Federal, State, and local law enforcement agencies working closely with scientists and engineers. The new standard includes minimum performance requirements for the ensembles, as well as four Law Enforcement Response Levels (LERL) based on expected mission requirements, durability and duration, and on the specific CBRN threat. The four types of ensembles provide different degrees of protection from liquid hazards, as well as various degrees of “stealth” with respect to visibility of an ensemble and the noise it makes. Standards already exist for CBRN ensembles for firefighters, but not the unique needs of law enforcement. The new CBRN standard is the first of its kind to address the specific needs of law enforcement.