Indoor air pollution is a major health risk for workers, especially in industries where fine particles are generated. Flour milling and packaging are two activities that are especially likely to release flour dust into the air. This is a known respiratory hazard and can also cause combustible dust explosions. At the Second Mills Company flour-packing plant in Riyadh, there was an excessive amount of flour dust building up around the carousel packing machine. This raised concerns about workers' safety and whether the company complied with industrial hygiene standards. To deal with this problem, a field study was carried out to measure exposure levels and test an affordable engineering control. An Extech VPC300 optical particle counter was used to collect thirty air samples at three significant locations during two work shifts. A Vevor portable ventilation fan with a five-meter flexible duct was installed in place at the main source of dust after baseline measurements were taken. Normality testing and a paired t-test were applied to statistically validate the effectiveness of the intervention. This study emphasizes the swift implementation and quantitative validation of a straightforward ducted local exhaust system through multi-channel real-time particle counting, contrasting with prior research that predominantly utilized gravimetric sampling or long-term modeling. Results showed a 55-62% drop in 0.5 µm particle counts and a change in severity rating from "hazardous" to "safe/low caution." This shows that a portable ducted ventilator is a practical and cost-effective way to improve indoor air quality and protect the health of workers in flour milling facilities.