Final answer:
Respirators must be approved by NIOSH.
Explanation:
Respirators must be approved by the National Institute for Occupational Safety and Health (NIOSH) organization. NIOSH is the federal agency responsible for conducting research and making recommendations for the prevention of work-related illness and injury.
Learn more about Occupational Safety and Health Administration (OSHA) here:
https://brainly.com/question/41545542
