On 1 August 2017, H2S concentrations were 0.017 mg/m3 of hydrogen sulfide (H2S) at the Tianjin Circulatory Economic Park, which met the standard and was below 71.7 per cent of the national standard (national standard 0.06 mg/m3). The concentration of ammonia (NH3) was 0.284 mg/m3 and 81.1 per cent of the standard and below the national standard (national standard 1.5 mg/m3). Methane (CH4) concentrations of 0 per cent, 100 per cent of the standard and below the national standard (national standard 0.1 per cent).
