Which type of asbestos removal activity is considered class II?

Class II asbestos removal activities specifically refer to the removal of materials that contain asbestos but are not classified as friable. This includes non-structural items such as wallboard, ceiling tiles, and similar materials. When these materials are being removed, the risk of asbestos fibers being released into the air is present, which necessitates careful handling and adherence to safety protocols.

In this context, the correct choice highlights activities where the potential for disturbing asbestos-containing materials (ACM) exists, thus requiring a stringent removal process. By focusing on wallboard and similar materials, it is evident that this activity involves direct interaction with potentially harmful materials, aligning perfectly with the definitions outlined for Class II activities.

Other options involve different circumstances: custodial work does not typically include aggressive disturbance of materials, repairing thermal insulation may involve some risk but is not classified under removal, and monitoring ACM presence is a survey activity rather than a removal operation. Each of these roles has importance in asbestos management, but they do not meet the criteria set for Class II removals.