In emergency management, the identification of hazards, analysis of risks, development of mitigation and response plans, maintaining of situational awareness and support of response and recovery are all complex responsibilities. A major accident brings together individuals belonging to many different organizations, having backgrounds in different fields of operation, and representing different organizational cultures. They have to absorb a large amount of information about the accident over a short period of time. In order to take effective action, actors are expected to work smoothly together, thus the flow of information from and to the actors involved is crucial. Nevertheless, there are certain problem domains in the different phases of emergency management, which may weaken the flow of information. In this paper we present the findings of the first round of a Delphi study in which we identified problem domains in communication both in long-term and short-term planning for major accidents.