The Emergency Preparedness Operational Command Unit (CO3) is a branch of the Central Operations directorate within London's Metropolitan Police Service. The unit's role is to ensure that the communities and the police of London are prepared and ready to deal with major terrorist attacks. This includes the forming of contingency plans, and organising training events for the Metropolitan Police to test their CBRN response. The unit was formed in 2004, under the Civil Contingencies Act 2004, which puts a responsibility on the Chief Officers of the MPS to ensure that the police are prepared.