Investigation of Gas Odorisation Practices and Safety Compliance in Residential Areas of Ibadan

Gas odorisation is a mandatory safety measure in natural gas distribution systems, enabling the detection of potentially dangerous leaks through the addition of odorant compounds, typically tertiary butyl mercaptan (TBM) or blends thereof. This study investigates the adequacy of gas odorisation practices and safety compliance levels in residential distribution networks in Ibadan, Oyo State. The research employs a field investigation methodology, combining odorant concentration measurements at residential service points using field olfactometry and portable gas chromatography, alongside structured interviews with gas utility staff and household consumers. Measurements are compared against the Nigerian gas safety regulation threshold requiring odorant detection at one-fifth of the lower explosive limit (LEL) of the gas. The study examines the odorant injection systems at key distribution stations, assessing injection consistency, odorant fade in polyethylene pipes, and calibration frequency of injection equipment. Findings indicate that odorant concentrations at peripheral residential service points fall below detectable levels in a significant proportion of tested locations, suggesting systemic odorant fade or inadequate injection rates. Consumer awareness surveys reveal that over 60 percent of respondents have limited understanding of gas odour significance and appropriate emergency responses. Recommendations include higher odorant injection rates for long distribution pipelines, consumer safety education campaigns, and mandatory odorant monitoring at distribution network extremities. This study contributes to improving residential gas safety in southwestern Nigeria. Keywords: gas odorisation, residential safety, Ibadan, odorant fade, gas leak detection.