Sound and thoughtful risk communication can help public officials in preventing ineffective, fear-driven, and potentially damaging public responses to serious crises. The cardinal rule of risk communication is: first do no harm. Setting clear communication goals and identifying support messages are decisions that should be made prior to the issuing of any public comment and are especially important in a crisis. These messages should ease public concern and give guidance on how to respond. Once goals and messages are established, the challenge becomes one of delivery and ensuring that messages are heard and goals are met. In a risk communications situation there is a constant tension between providing accurate information and providing information quickly. Both demands pose dangers. Scientific information is more useful to the audience if the information provided is relevant and easily understood. Recognizing and admitting uncertainty is the reality of most risk communication situations. Communicators are faced with many barriers because the risk communication process is so deeply embedded in broader social issues. Myths, such as issues are too difficult for the public to understand, may interfere with the development of an effective risk communication program. Audiences must perceive the communicator to be trustworthy and believable. It is important to avoid communication pitfalls, such as abstractions, blame, and use of jargon. Issues of health and safety can arouse strong emotions, such as anger and hostility. Forming positive relationships with the news media is crucial to communication success. If substantive inaccuracies occur, the public official should move very quickly to correct them. Personal strengths and weaknesses should be assessed. Presenting information at public meetings and recognizing opportunities to speak out are also discussed. 19 references