"Sensitization" is another term for what?

Sensitization refers to a process in which an individual's immune system becomes increasingly reactive to a substance after initial exposure, leading to allergic effects upon subsequent exposures. When sensitization occurs, the body develops a memory of the allergen, resulting in a heightened response that can manifest as allergic reactions, which may include symptoms such as rashes, respiratory issues, or other forms of irritation.

The other terms presented do not accurately capture the essence of sensitization. Skin irritation typically refers to a local response to a chemical or irritant but does not involve the immune system's acquired sensitivity. Chemical resistance pertains to an organism's ability to withstand the effects of a certain chemical without harmful effects, which is distinct from the immunological response characterized by sensitization. Environmental impact generally describes the effect of an action or substance on the environment, which does not directly relate to individual immune responses. Therefore, allergic effects are clearly the closest match to the definition of sensitization.