Final answer:
In non-hazardous atmospheres, employees must be given the opportunity to wear the respirator and become familiar with it before wearing it in a hazardous atmosphere.
Step-by-step explanation:
In non-hazardous atmosphere, employees must be given the opportunity to wear the respirator and become familiar with it before wearing it in a hazardous atmosphere. This is because non-hazardous atmospheres provide a safe environment for employees to practice using the respirator and understand its functionality.