What additive prevents tarp material from breaking down and leaking when exposed to sunlight?

The correct choice focuses on the role of a UV stabilizer, which is specifically designed to protect materials from the degradation caused by ultraviolet (UV) radiation present in sunlight. Tarp materials can be particularly susceptible to breaking down when exposed to these elements, leading to potential leaks and loss of effectiveness in their protective functions.

A UV stabilizer works by absorbing or reflecting harmful UV rays, minimizing the chemical reactions that lead to material breakdown. This ensures the longevity and durability of the tarp, making it crucial for applications that involve prolonged outdoor exposure, such as in fumigation where maintaining a seal is essential for safety and efficacy.

While a chemical stabilizer may offer various forms of protection, it does not specifically address UV exposure. Similarly, a moisture barrier pertains to preventing water penetration rather than UV-related deterioration. An adhesive enhancer is unrelated to the protection of materials from sunlight and instead focuses on improving the bonding strength of adhesives used in the application. Therefore, the UV stabilizer is the most appropriate and effective choice for preventing tarp material breakdown when exposed to sunlight.