Simple and Low-Cost Visual Inspection of Engineering Control in Science Laboratories

Abstract

To control chemical hazard, engineering control is one of the Hierarchy of Controls that protects workers from chemical hazard. Engineering control is accomplished by removing hazardous conditions by placing a barrier between the worker and the hazard. Local ventilation system is widely used in laboratories to remove any chemical agents that are released from any chemical reactions. The importance of these ventilation systems is to prevent any health complications to persons in the laboratory due to chemical exposure. İn this paper, the effects and effectiveness of sash height to vapor source position to effectiveness of local exhaust ventilation (LEV) system were studied and identified using vapor flow from the stimulated carbon dioxide (CO₂) and water vapor. Eight LEVs were inspected. The stimulated vapor as a tracer was produced by mixing dry ice into hot-boiled water (100^oC). The dispersion stimulated CO₂ and water vapor inside and outside the LEV system, and this can predict the efficiency of LEV systems based on visual inspection. The results revealed that each LEV showed a different time taken to draw out the vapor from the inside of the fume hood.