VOC gas sensor MiCS5524 breakout board.
This sensor is sensitive to CO ( ~ 1 to 1000 ppm), Ammonia (~ 1 to 500 ppm), Ethanol (~ 10 to 500 ppm), H2 (~ 1 - 1000 ppm), and Methane / Propane / Iso-Butane (~ 1,000++ ppm). However, it can't tell you which gas it has detected.
