The document describes an air quality monitoring system using Internet of Things (IoT) technology to detect gas leakages at low cost. The system uses a NodeMCU microcontroller connected to an MQ-6 gas sensor to detect levels of LPG, butane, and propane in the air. When gas is detected above a threshold, a buzzer sounds an alarm. Gas level readings are transmitted wirelessly via the NodeMCU and displayed on a web page, indicating the location of any gas leak. The system provides real-time air quality monitoring to improve safety and prevent fires and explosions from gas leaks in industrial settings.