"Sensitization" is another term for what?

Sensitization refers specifically to allergic effects, which occur when the immune system becomes reactive to a substance after repeated exposure. The first exposure may not cause any noticeable reaction, but subsequent exposures can trigger an immune response, leading to symptoms such as rashes, respiratory issues, or other allergic reactions. This process indicates a heightened sensitivity developed towards the allergen due to prior contact.

The other options represent different concepts. Skin irritation pertains to a direct toxic effect on the skin without necessarily involving the immune system in the way that sensitization does. Chemical resistance refers to the ability of organisms to withstand harmful effects from chemicals, while environmental impact generally concerns how a substance behaves in the environment and its effects on ecosystems, rather than on human health or allergic reactions. Thus, the term "sensitization" aligns most closely with allergic effects, making it the correct choice.