In the last decade, more than 1500 MT of steel was produced annually, and more than 60% of the demand is met by the integrated blast furnace - basic oxygen furnace route (BF-BOF). Carbon is used as an energy carrier and reducing agent in the BF-BOF route which causes ~7% of global CO2 emissions. Hydrogen-based iron ore reduction has attracted immense attention as a new green steel production pathway. However, using hydrogen as a reducing agent in the steelmaking process implies an important question: What is the hydrogen content in green steel produced through hydrogen metallurgy? To answer this question, we quantified the hydrogen concentration of green steel produced with both hydrogen-based direct reduction and hydrogen-based plasma reduction using thermal desorption spectroscopy and a hot extraction test. Our study answers a crucial question that must be addressed before the transition of the iron and steel industry to hydrogen embrittlement.