A variety of atmospheric pollutants undergo complex processes that alter their concentrations. Notably, volatile organic compounds (VOCs) from industrial sources are crucial as they actively participate in the formation of ozone and particulate matter (PM), impacting health, climate, and ecosystems. Further, they can be directly harmful, such as vinyl chloride monomer (chloroethene), benzene or 1-3-butadiene, that are carcinogenic. The southern region of France often exceeds ozone (240 µg m³ hourly) and PM2.5 (10 µg m³ annual) French thresholds, as evidenced by a 2018 study. These exceedances contributed to over 1,800 hospitalizations in the region from 2010 to 2019. To better understand the drivers behind these exceedances and anticipate the population’s exposure, a detailed study in an impacted industrial area is conducted. We developped an multisite approach for online VOC measurements and present the QA/QC method and a novel uncertainty calculation. The results of this uncertainty calculation show compliance with Directive 2008/50/EC, which sets a 25% limit for fixed measurements with a benzene concentration of 5 µg m-³, the only regulated VOC. The new Incert'R tool functionality for automatic VOC uncertainty calculations will save significant time. The resulting data will serve as a base for future work to quantify and characterize VOC sources in real time at three sites using Positive Matrix Factorization (PMF).