Which of the following is NOT a required safety equipment for jackhammer operators?

The choice of respiratory masks as not being required safety equipment for jackhammer operators is correct in this context. While jackhammer operation does entail exposure to noise and potential debris, the specific requirement for respiratory protection depends largely on the environment and the materials being worked with rather than the tool itself. In most standard conditions where jackhammers are used, adequate safety measures such as hearing protection, hard hats, and eye protection are emphasized to protect against immediate physical hazards such as falling objects, flying debris, and excessive noise from the equipment.

Hard-toed footwear, hard hats, and eye and ear protection are generally mandated to prevent injuries in the event of falling objects or equipment malfunction and to reduce the risk of hearing damage from the loud noise generated by the jackhammer. Therefore, while respiratory protection may be necessary in environments with specific airborne contaminants or substances, it is not universally required for all jackhammer operations, making it the correct answer to the question.