What is the primary purpose of using a sealant on asbestos?

The primary purpose of using a sealant on asbestos is to encapsulate and prevent fiber release. Asbestos materials can be harmful when their fibers are disturbed and become airborne, posing serious health risks if inhaled. The application of a sealant creates a protective barrier around the asbestos material, effectively preventing fibers from escaping into the air. This encapsulation maintains the integrity of the asbestos, allowing for safer management of the material without immediate removal, which can be more disruptive and dangerous.

The other options do not align with the primary health and safety intent behind using sealants with asbestos. Making materials visually appealing or enhancing thermal insulation are not the main goals when dealing with hazardous asbestos materials. Similarly, while sealants may sometimes be painted over, the preparatory function for painting is secondary to their primary role in fiber containment.