An NBC (nuclear, biological, chemical) suit, also called a chemsuit, chem suit, or chemical suit is a type of military personal protective equipment. NBC suits are designed to provide protection against direct contact with and contamination by radioactive, biological or chemical substances, and provide protection from contamination with radioactive materials and all types of radiation. They are generally designed to be worn for extended periods to allow the wearer to fight (or generally function) while under threat of or under actual nuclear, biological, or chemical attack. The civilian equivalent is the hazmat suit. The term NBC has been replaced by CBRN (chemical, biological, radiological, nuclear), with the addition of the new threat of radiological weapons.