Final answer:
The statement is false; hearing protection should be worn for the entire 8-hour shift when exposed to 85 decibels to prevent hearing damage, according to recommendations by health agencies.
Step-by-step explanation:
The statement that exposure to 85 decibels over an 8-hour shift is permissible, so long as muffs are worn for at least four hours of the shift, is not accurate based on the information provided. Several government agencies and health-related professional associations recommend that 85 dB not be exceeded for 8-hour daily exposures in the absence of hearing protection. This implies that for the full duration of the exposure, or the entire 8-hour shift, proper hearing protection should be used to prevent hearing damage, rather than only for a portion of the time.