“…As recommended by a more quantitative approach, similar to the NSF 49 procedure for biological safety cabinets,@) might lead to a better understanding of fume hood limitations and the evaluation of potential exposure to fume hood users and other building occupants. (Note: Dioctylsebacate or another substitute for DOP should be used, since DOP is a class IIB carcinogen (18) with an Occupational Safety and Health Administration permissible exposure limit of 5 mg/m3. )…”