Chemical agents are substances that can cause harm to living organisms through chemical reactions. They are often used in warfare, pest control, and industrial applications. Examples include nerve agents like Sarin and blister agents like Mustard Gas, which can have devastating effects on human health and the environment. In addition to their military applications, chemical agents are also studied in toxicology to understand their effects on biological systems. Regulatory bodies, such as the Environmental Protection Agency, monitor and control the use of these substances to protect public health and safety.