Inherent occupational health assessment for chemical batch processes

Abstract

The purpose of this study is to develop the methodology to assess inherent occupational health hazards for chemical batch process. Evaluation of potential hazards during the early stage of process design is critical so that the hazards can be tackled earlier before the process is constructed. Besides, the cost associated with any conceptual modification at this stage is so much lower compared to the later stages of the project lifecycle. Nowadays, batch process is favoured in many chemical industries especially pharmaceutical and specialty chemical. Since batch operation involves more manual handlings compared to continuous processes, it is important to assess occupational health hazards as a result of workplace exposure among workers especially to harmful substances. Most of the available methods for hazard assessment in batch processes were developed for safety rather than health hazard. In this study, an assessment method is proposed based on index-based approach to evaluate potential hazards in batch chemical process during the conceptual design stage. The parameters from the process, either due to chemical properties, process conditions or the operation of the unit operations that may cause occupational health hazards to the exposed workers were included in the index. The index was demonstrated on a real case of Eurycoma Longifolia (Tongkat Ali) water extraction. From the case study, the potential hazards of each unit operation can be evaluated through the index calculated. Comparison of exposure (hazards) for each unit operation in the process is able to highlight the critical parameters or conditions that need to be adjusted, so that the process can be less hazardous especially from the occupational health point of view. Based on the index calculated, the process can be designed to be less hazardous during the early design phase in the process development.