vesicant vs. irritant

vesicant

adjective

  1. producing a blister or blisters, as a medicinal substance; vesicating.

noun

  1. a vesicant agent or substance.

  2. (in chemical warfare) a chemical agent that causes burns and destruction of tissue both internally and externally.

irritant

adjective

  1. tending to cause irritation; irritating. irritating.

noun

  1. anything that irritates.

  2. Physiology, Pathology.,  a biological, chemical, or physical agent that stimulates a characteristic function or elicits a response, especially an inflammatory response.