Transformer manufacturing industry uses volatile organic compounds (VOCs) containing materials such as varnish which can cause adverse health effects to human. Exposure to a high level of VOCs could disrupt the normal functions of a human lung.Therefore, this study was conducted to evaluate the status of lung functions of the workers exposed to VOCs at a transformer manufacturing plant in Selangor. The volatile organic compounds (VOCs) concentration in the office and production area was measured using direct-reading method and 60 subjects were selected to undergo the lung function test. The FVC and FEV1 values showed significant difference (p<0.05) between the exposed group and the non-exposed group. The mean readings of FVC (69.07±12.58) and FEV₁ (72.90±10.46) of the exposed groups were lower than the non-exposed group, which were 81.47±9.78 and 84.23±9.07, respectively. In contrast to the FEV1/FVC parameters, the non-exposed group (102.93 ± 7.17) showed lower mean values than the exposed group (105.90±8.98). Besides that, the nasal symptoms showed significant differences (p<0.05) between the exposed and non-exposed group. The demographic data of the exposed group showed no association with the lung function status of the exposed group workers. However, the lung functions of the exposed group were influenced by the concentration of VOCs in the production area. High concentration of VOCs may cause detrimental effects on the lung functions. Therefore, management or employers in the industry should always be aware of the effects of VOCs, and take appropriate steps to ensure the safety and welfare of the employees.

Introduction: As humans spend 90% of their time inside, indoor air quality (IAQ) is critical for occupant health. The primary concern associated with low IAQ is its impact on employees’ health, comfort, and productivity. In accordance with the Industry Code of Practice on Indoor Air Quality 2010 (ICOP IAQ 2010), a ten-parameter assessment was conducted in the office of the transformer manufacturing factory in Selangor, Malaysia. Methods: The measured parameters are temperature, air movement, relative humidity, carbon dioxide (CO2 ), carbon monoxide (CO), formaldehyde (CH2 O), particulate matter (PM10), total volatile organic compounds (TVOCs), total fungal count (TFC), and total bacterial count (TBC). This study employed both qualitative and quantitative approaches by distributing questionnaires (N = 42), and measuring the indoor air quality parameters with integrated equipment at selected stations and comparing them to the ICOP IAQ 2010 standard. Results: A majority of the measures, with the exception of air movement, CO2 , and TBC, complied with the ICOP IAQ 2010 standards. The one-way ANOVA test showed that there were significant differences (p < 0.05) for the parameters of temperature, PM10, and TVOCs. The ChiSquare test revealed that sleepiness was a symptom of the sick building syndrome, affecting both male and female employees the most frequently and significantly. Conclusion: Air movement, CO2 , and TBC values that did not meet ICOP IAQ 2010 requirements revealed poor IAQ at the study site, which could have a negative influence on the employees’ health. To cut down on air pollution, the improvement on the ventilation system should be done to reduce the risks to the employees’ health.