Chemical Health Risk Assessment and Evaluation of Risk toward Ototoxicants among Workers at Palm Oil Mills

Chemical and noise hazards are known to have a synergistic effect, where a variety of different chemical substances may worsen hearing damage in humans. These chemical substances are identified as ototoxicants that are toxic to the auditory system. This study evaluated the issue and created a framework in which these ototoxicants can be recognized early in the workplace. The approach involved hazard identification of chemicals hazardous to health, observation of tasks related to chemicals, identification of ototoxicants and noise exposure, evaluation of risks, and determination of the adequacy of control measures in accordance with the DOSH Malaysia Chemical Health Risk Assessment (CHRA) Third Edition Manual 2017 and the Industry Code of Practice for Management of Occupational Noise Exposure and Hearing Conservation 2019. The target subjects of this study involved 148 palm oil mill workers at two different locations who are exposed to both chemicals and noise throughout their daily tasks. Four work units (i.e., boiler operators and welders at palm oil mill A and laboratory analysts and welders at palm oil mill B) were concluded to have a significant risk of exposure to ototoxicants due to the high noise exposure, inadequacy of engineering control, and unsuitable use of PPE.