Chemical, biological, radiological and nuclear defense (CBRN defense or CBRNE defense) is protective measures taken in situations in which chemical, biological, radiological or nuclear warfare (including terrorism) hazards may be present. CBRN defense consists of CBRN passive protection, contamination avoidance and CBRN mitigation.
A CBRN incident differs from a hazardous material incident in both scope (i.e., CBRN can be a mass casualty situation) and intent. CBRN incidents are responded to under the assumption that they are intentional and malicious; evidence preservation and perpetrator apprehension are of greater concern than with HAZMAT incidents.
A 2011 forecast concluded that worldwide government spending on CBRN defence products and services would reach US$8.38bn that year.
In English the term CBRN is a replacement for the cold war term NBC (nuclear, biological, and chemical), which had replaced the term ABC (atomic, biological, and chemical) that was used in the fifties. The addition of the R (for radiological) is a consequence of the "new" threat of a radiological weapon (also known as "dirty bombs"). In the new millennium, the term CBRNe was introduced as an extension of CBRN - the e in this term representing the enhanced (improvised) explosives threat.
In Spanish the term NRBQ (Nuclear, Radiológico, Bacteriológico y Químico) has replaced NBQ.
The Argentine Armed Forces has the Batallón de Ingenieros QBN 601 of the Argentine Army, was the first CRBN response team created, in the 1990s, as a part of the country's Rapid Deployment Force. The Policía Federal Argentina have the BRIGADA DE RIESGOS ESPECIALES (BRE), this unit is the only national response for CBRN/HAZMAT incidents. Also, has a three units called: RIESGO QUIMICO Y BIOLOGICO, RIESGO RADIOLOGICO Y NUCLEAR, and the tactical response unit called PROTECCION QBNR.