Komparasi Lingkungan Termal Gedung Baru Dan Lama Terhadap Heat Strain Operator Press Rubber Menggunakan HI Dan PSI Di PT XYZ

M. Alfarizi (Universitas Tangerang Raya)
Angga Widyas Swara (Tangerang Raya University)
Sita Kurniaty Ratoko (Tangerang Raya University)

Science and Education Journal
Vol 5 No 3 (2026): Science and Education Journal 2026

The footwear manufacturing industry inherently involves physical hazards in the form of exposure to a hot working climate, particularly in the press rubber process that utilizes high-temperature heating machines. This study aims to measure and compare the level of heat strain experienced by operators in two production facilities with different ventilation systems, namely the New Building (mechanically ventilated) and the Old Building (naturally ventilated) at PT XYZ. The evaluation was conducted by combining environmental indicators using the Heat Index (HI) and internal physiological load indicators via the Physiological Strain Index (PSI). This comparative quantitative study involved 30 Shift 1 operators (15 operators per building) over a 15-day observation period. The parameters measured included air temperature, relative humidity, heart rate, skin surface temperature, as well as the Subjective Fatigue Assessment (SFA) questionnaire. The results indicated a highly significant disparity in thermal loads. At the peak hour (13:00 WIB), the Heat Index in the New Building was recorded at 48.8°C (Danger Category) with an average PSI of 4.06 (Moderate Strain). In contrast, the absence of mechanical air circulation in the Old Building led to extreme heat stagnation, causing the Heat Index to surge to 66.2°C (Extreme Danger Category) and elevating the average PSI to 6.25 (High Strain). These critical conditions in the Old Building were subjectively validated, revealing that 80% of the operators experienced decreased cognitive alertness and dizziness, thereby increasing the risk of human error. As a mitigation strategy, improvements in the Occupational Health and Safety (OHS) hierarchy are recommended. These include engineering controls through the installation of Canopy Hood-type Local Exhaust Ventilation (LEV), the implementation of structured micro-breaks, and the provision of Personal Protective Equipment (PPE) such as Phase Change Cooling Vests specifically for operators in the Old Building.