Qualitative assessment of local ventilation in Petrochemical Company Laboratories for Reducing Staffs Exposure

Chemicals are serious harmful agents in the workplace، especially chemistry labs. This material may cause poisoning and different diseases. Laboratory hoods as first safety device protect laboratory workers against hazardous chemicals. This research conducted on chemistry labs in a petrochemical company for awareness of the hoods performance and proposed the needed reforms. In this study، in the studied laboratories، in order to evaluate performance of lab hoods، a capture velocity for 22 chemical hoods was conducted. Information concerning the structural characteristics of the baffle position، airfoil and opening area of hood s and situational characteristics their position relative to the air stream sources include general ventilation system vents، doors and windows of the laboratory were gathered. The mean velocity of hoods compared to the minimum acceptable value of 80 fpm showed that the only 9. 09 % of their hoods can provide an acceptable velocity. There was a significant relationship between the numerical value of the velocity and position features hoods structure (Pvalue<0/05). The results should that the structure of hood s and their locations in the studied laboratory concerning air flow sources must be corrected so that the velocity and performance of hoods being must provided and maintained.