What term describes chemicals that cause permanent visible destruction or change in living tissue at the site of contact?

The term that best describes chemicals capable of causing permanent visible destruction or change in living tissue at the site of contact is "corrosives." Corrosives are substances that can cause significant damage to skin, eyes, or any other tissues upon direct exposure. They work by chemically interacting with the tissue, often leading to burns or irreversible injury. This characteristic makes them particularly dangerous in various settings, including esthetics, where the safety of skin integrity is paramount.

In contrast, toxins are generally harmful substances that can impair body function but may not cause immediate visible damage at the site of contact. Carcinogens are agents that can lead to cancer with prolonged exposure, rather than causing immediate destruction or visible change. Allergens are substances that can cause allergic reactions in sensitive individuals, which may not involve tissue destruction but rather an immune response. Thus, corrosives clearly define agents that exhibit the specific action of causing permanent change when they come into contact with living tissues.