Correct answer: (B) Lead to increased workplace contaminant concentrations.
Explanation
The intended controlled system increases local circulation while maintaining the required fresh-air supply and acceptable contaminant control. Extra fan equipment may be used and overall conditioning/ventilation cost can fall. Thus B is the intended wrong claim about the properly controlled application. Uncontrolled or inadequately diluted recirculation can in fact accumulate contaminants; that is precisely what the control requirement must prevent.
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