Chemical incidents refer to such incidents that hazardous chemicals cause acute poisoning of humans or social harms due to unexpected reasons. According to objects contaminated by poisonous and hazardous chemicals, the chemical incidents can be classified as air pollution incidents, water pollution incidents; while according to releases of poisonous and hazardous chemicals, the chemical incidents can be classified as direct leakage chemical incidents and secondary release chemical incidents etc. In Shanghai, hazardous chemicals are produced, stored, transported and used every day of wide varieties and large quantities, chemical incidents might happen at any time, therefore, it is significant to effectively and promptly organize the public to carry out protection measures when chemical incidents occur.

When chemical incidents occur, main public protection measures are adopted as follows: First, arrange protections for personnel in polluted areas. For areas polluted or to be polluted by contaminated air, inform the residents immediately to carry out respiratory protections. Second, control the polluted areas. Mark, isolate and set warnings in areas polluted by toxic and hazardous chemicals to prevent irrelevant personnel entering into these areas and being injured. Third, organize the residents to evacuate promptly. In areas polluted by chemicals, if the contaminated air might last for a long time, organize the residents and the public to evacuate the polluted areas when the contamination density in the air declines obviously so as not to cause significant injuries to humans; For areas the contaminated air will or might pollute, when the contaminated air does not arrive at these areas, leaving enough time to organize the residents to evacuate, quickly organize the residents and the public to transfer to safer areas. Four, carry out sterilization as appropriate. If necessary, carry out sterilization to contaminated staff, articles, the ground, air and water sources. In addition, isolate (control) the accident sources, carry out detection and monitoring and rescue poisoned humans etc.

When chemical terrorist attacks happen, quickly organize all staff in attacked areas to evacuate the areas in order to safer places, of which other public protection measures adopted are similar to that for chemical incidents.