What is applied to the substrate and remaining plastic?

The correct response is related to the use of sealants in asbestos abatement and containment processes. After the removal or encapsulation of asbestos-containing materials, applying a sealant is a crucial step. Sealants are specifically designed to provide a protective barrier over asbestos fibers, preventing their release into the air, thereby minimizing exposure risks.

Using a sealant also enhances the durability and stability of the materials involved, such as the underlying substrate and any remaining plastic sheeting that might have been used during the abatement process. Sealants can effectively bind to these surfaces, providing an additional layer of safety by sealing any microscopic gaps through which asbestos fibers could potentially escape.

Other substances listed, such as water, paint, or adhesive, do not serve the same purpose in the context of asbestos abatement. Water might be used during initial removal to suppress dust, but it does not seal or protect. Paint could potentially cover surfaces but lacks the specific properties required to ensure safety against asbestos release. Adhesives may be useful during installation processes but are not designed to encapsulate or seal asbestos effectively. Therefore, the application of sealant is the correct choice, as it directly addresses the safety and containment requirements of asbestos abatement.