The activation of a plan is not automatic. Health workers have to be trained for the processes involved. The mechanisms for implementing the response plan should be clearly formulated. Depending on nature of the disaster, different phases can be defined:

a) Alert phase: Once an emergency is occurs, a telephone chain should operate based on registered names, addresses and telephone numbers. There should be alternate mechanisms for contact in case of power outage or interruption of telephone service. The plan should include warning systems as a part of intersectoral plans for different types of emergency, so that the public can take preventive and protective measures in coordination with national disaster management agencies or civil defense institutions. Where appropriate, this may include evacuation to temporary shelters or camps.