Sanitation workers continue to face life-threatening risks while cleaning sewers and septic tanks, mainly due to toxic gases such as hydrogen sulphide (H₂S), methane (CH₄), ammonia (NH₃), and carbon monoxide (CO). Despite strict regulations, accidents still occur because most available gas detectors are bulky, expensive, and unable to give real- time warnings. To address this gap, we developed a compact and affordable smart device that can detect multiple hazardous gases and instantly alert workers and supervisors. The device uses MQ-series sensors and an ESP32 microcontroller to continuously monitor air quality, while a mobile app and cloud platform (Firebase) provide real- time data, notifications, and trend analysis. A 3D-printed casing makes the system portable and durable in field conditions. Testing showed more than 95% accuracy when compared with industrial gas meters, with alerts reaching users in just a few seconds. Field trials with municipal workers confirmed that the device is easy to use and effective in improving safety. By aligning with Sustainable Development Goals (SDG 6 & 11), this work not only enhances worker protection but also contributes to safer sanitation practices and smarter urban infrastructure.

Sanitation workers continue to face life-threatening risks while cleaning sewers and septic tanks, mainly due to toxic gases such as hydrogen sulphide (H₂S), methane (CH₄), ammonia (NH₃), and carbon monoxide (CO). Despite strict regulations, accidents still occur because most available gas detectors are bulky, expensive, and unable to give real- time warnings. To address this gap, we developed a compact and affordable smart device that can detect multiple hazardous gases and instantly alert workers and supervisors. The device uses MQ-series sensors and an ESP32 microcontroller to continuously monitor air quality, while a mobile app and cloud platform (Firebase) provide real- time data, notifications, and trend analysis. A 3D-printed casing makes the system portable and durable in field conditions. Testing showed more than 95% accuracy when compared with industrial gas meters, with alerts reaching users in just a few seconds. Field trials with municipal workers confirmed that the device is easy to use and effective in improving safety. By aligning with Sustainable Development Goals (SDG 6 & 11), this work not only enhances worker protection but also contributes to safer sanitation practices and smarter urban infrastructure.