Evaluation of the workers exposure to heat and presenting intervention to control heat stress in profile factory

Background & Objectives : Exposure to heat is a significant problem in the Industries. The present study aimed at the evaluation of thermal risk, measurement of heat stress index, and proposing a plan for heat control in cutting and welding units in profile factory . Methods : The data of study was analyzed through the measurement of physical parameters with digital WBGT device and silvered Kata thermometer. Workers’ thermal comfort was calculated based on predicted mean voted (PMV) and predicted percentage of dissatisfied (PPD) with regard to the computed parameters. In order to control heat stress, an aluminum-insulated wall was used and airflow velocity was increased in cutting and welding units. Results : The results of the WBGT index before and after the intervention using the shield were 30.8° C and 23.2° C, and by increasing airflow velocity were 30° C and 29.5° C respectively. In addition, the obtained results for PMV and PPD by using the shield were 1.38 and %44, and by increasing airflow velocity they were %90 and 2.56 respectively. The results confirmed by using the shield the measured WBGT index was lower than the occupational exposure limit (28 ◦ c). Conclusion : The results showed that by appropriate designing and using control methods, such as insulation shield and increased airflow velocity, optimal thermal comfort based on national heat exposure limits could be reached