Qualitative Evaluation of Chemical hoods Performance of Laboratories of the University of Medical Sciences

The scientific and research laboratories at universities of medical sciences use a variety of chemical and biological materials. Various people, including the laboratory staff, students, and faculty members, are exposed to these materials, and various respiratory and dermatological symptoms may occur in these people. The purpose of this study is to evaluate the use and control of such chemicals in the laboratories of medical university. In this study, we investigated 43 chemical hoods in laboratories at universities of medical sciences. The technical specifications of the hoods and their compliance with the standards were investigated. The amount of hood suction was measured by using Flow visualization and the face velocity of the hoods using a thermal anemometer. The results were analyzed by SPSS software, version 19. 51.2 percentage of the hoods in terms of hardware and 44.2 percentage in terms of locations had inappropriate conditions. Maximum of face velocity was 96.16 ft/min. The results showed that 50.2% of the hoods had visible leakage. The mean face velocities were not suitable in any of the hoods when they were fully open or 50% open. These velocities were appropriate only when the hoods were 25% open. Most hoods had inappropriate conditions, and their face velocities were low, mainly due to inadequate fans. Further investigation and correction of technical problems are needed. Also, the performance of the hoods should be evaluated annually