Final answer:
The qualification needed to second check a hanging tag typically is an electrical certification, which acknowledges the individual's ability to recognize electrical hazards.
Step-by-step explanation:
The qualification required to second check a hanging tag is often dependent on the workplace's safety protocols and regulations. However, in most cases, a specific electrical certification is usually required to second check a hanging tag because it implies the ability to understand and identify potential electrical hazards. Furthermore, having a supervisor's approval and a mechanical engineering degree may be beneficial but not typically mandatory unless specified by the employer or the complexity of the tasks associated with the tag-out/lock-out procedures.