The employer must retrain an employee when the employer has reason to believe the employee does not have the understanding and skill required by paragraphs (a) and (b) of this section. Situations requiring retraining include, but are not limited to, the following:
When changes in the workplace render previous training obsolete or inadequate;
When changes in the types of fall protection systems or equipment to be used render previous training obsolete or inadequate; or
When inadequacies in an affected employee's knowledge or use of fall protection systems or equipment indicate that the employee no longer has the requisite understanding or skill necessary to use equipment or perform the job safely.