nonvesicant

In toxicology and occupational safety, a nonvesicant is a chemical agent that does not cause vesication, or blistering, when it contacts skin or mucous membranes. This term differentiates substances that do not produce the tissue-blistering effects associated with vesicants such as sulfur mustard and related warfare agents. Nonvesicants may still be harmful through irritation, corrosion, or systemic effects.

Whether a chemical is nonvesicant depends on factors such as dose, exposure duration, concentration, and the route of exposure (skin, eye, inhalation). Some agents traditionally labeled as nonvesicants can cause significant injury at high concentrations or with prolonged contact, even if they do not form classic vesicles. Conversely, some vesicants may produce only mild irritation at low-dose exposures.

Commonly encountered nonvesicants include certain irritants such as chlorine gas and ammonia, as well as selected solvents and some acids and bases that irritate rather than blister at typical exposure levels. The term is frequently used in industrial hygiene and emergency response to categorize potential injury patterns rather than to imply safety.

Safety emphasis for nonvesicants focuses on prevention of exposure through ventilation, containment, and personal protective equipment, along with rapid decontamination and symptomatic care if exposure occurs. Treatment is tailored to the specific agent and route of exposure, with attention to airway, eye, and skin integrity.