Which of the following examples is a toxic agent?

Ricin is classified as a highly toxic agent because it is a potent toxin derived from the seeds of the castor oil plant. It works by inhibiting protein synthesis within cells, which can lead to cell death and ultimately, systemic failure, making it extremely dangerous even in small amounts. Its use and potential for harm are well-documented; even tiny doses can be lethal if ingested, inhaled, or injected.

While sodium pentothal is a barbiturate used primarily as an anesthetic, and glyphosate is a widely used herbicide that, while controversial regarding its safety for humans and the environment, is not classified as a toxin in the same sense as ricin. The term “herbicide” refers to a category of chemicals used to kill unwanted plants, which may include substances that can be toxic under specific conditions but does not inherently mean they are as lethal or harmful as ricin. Hence, ricin stands out as the clear example of a toxic agent in this context.