Chemical, biological, radiological and nuclear defence (CBRN defence) are protective measures taken in situations in which chemical, biological, radiological or nuclear warfare (including terrorism) hazards may be present. CBRN defence consists of CBRN passive protection, contamination avoidance, and weapons of mass destruction mitigation. A 2011 forecast concluded that worldwide government spending on CBRN defence products and services would reach US$8.38bn that year.