Riot control agent. After September 11, 2001, the _____________ was established to provide a framework that provides a comprehensive national approach, applicable at all jurisdictional levels and across functional disciplines.
noun, plural: chemicals. (1) A substance made up of chemical elements or produced from a chemical process. (2) A drug, especially illicit or addictive drug. adjective. Of, relating to, or pertaining to, chemistry or a chemical substance.
Chemistry. a substance that causes or accelerates a chemical reaction without itself being affected. 2. something that causes activity between two or more persons or forces without itself being affected. 3. a person or thing that precipitates an event or change: