Personal Safety Considerations: When approaching a scene that may involve chemical, biological, or radiological materials the most critical consideration is the safety of oneself and other responders. Be cognizant that the presence and identification of hazardous agents may not be immediately verifiable, especially in the case of biological and radiological agents. The following actions/measures to be considered by first responders are applicable to either a chemical, biological, or radiological incident. The guidance is general in nature, not all encompassing, and its applicability should be evaluated on a case-by-case basis by the first responders