Odor nuisance in block rubber and compound rubber manufacturing plants poses an important environmental management challenge, particularly under actual industrial operating conditions. This study aims to systematically analyze the sources and root causes of odor generation associated with the use of cup lump rubber as a raw material and to develop effective mitigation measures appropriate for factory operations. Qualitative problem analysis tools, including the Fishbone Diagram (4M framework) and Why–Why Analysis, were applied to identify key factors contributing to odor emissions. The analysis identified four principal root causes related to raw material stockpiling practices, odor control equipment performance, deodorizing agent effectiveness, and the lack of systematic odor monitoring. Accordingly, targeted improvement measures were implemented, resulting in a 50% reduction in stockpile volume, enhanced spraying system performance, replacement of effective microorganisms (EM) with wood vinegar, and the introduction of odor intensity measurement at the plant boundary. After implementation, the measured odor intensity was 25, which is below the regulatory limit of 30, indicating compliance with the Ministry of Industry Regulation on Determining Odor Standards in the Air from Factories, B.E. 2568 (2025). The results demonstrate that systematic problem analysis combined with targeted operational improvements can effectively mitigate odor nuisance and support sustainable industrial operations in compliance with regulatory requirements.

Keywords

Cup lump rubber, Rubber manufacturing, Odor control agents, Root cause analysis, Sensory-based odor assessment