Hydrogen Sulfide Measurement from Degraded Corrosion Inhibitor as Occupational Health Control in Oil & Gas Industry

Introduction: Corrosion inhibitor (CI) is a chemical for pipe corrosion protection with sulfur-containing substances in the product. One type of substances is thioglycolic acid (TGA). Besides having benefits in maintaining pipe integrity, TGA can be decomposed to H₂S (hydrogen sulfide) due to changes in ambient temperature during storage, such as direct sunlight exposure. This irritant gas can pose a risk to the health of chemical workers. Therefore, this study aims to measure the concentration of H₂S in a CI product containing TGA. Method: The data were collected from an oil and gas company measurement report on 12 CI drums with 1-3%w of TGA content by using a glass tube detector. Measurements were performed by varying the measurement distance (0 and 10 cm from the mouth of the drum), observing the condition of the inflated drum surface, and determining the existence of internal pressure. Results: All samples contained H₂S, and the inflated drums had higher H₂S content than those that were not inflated up to more than 200 ppm in the drum bore. At this concentration, workers can experience pulmonary edema significantly prolonged exposure. Biological monitoring can be conducted by analyzing thiosulfate content in urine and blood after exposure or routine examination at the end of the work shift. Conclusion: Degraded CI with TGA content could contain H₂S and it will be risky for workers health. The H₂S concentration measurement is part of administration and engineering control in oil and gas industry.