Fusion bonded epoxies (FBE) in combination with cathodic protection (CP) are widely used to protect the soil side of buried pipelines from corrosion. Cathodic disbonding of the epoxy coating is a degradation process involving accelerated loss of adhesion of FBE because of chemical and electrochemical processes due to CP. Results are presented from our study to determine the mechanism of cathodic disbonding. A primary focus is on determination of the role of oxygen reduction products, e.g. hydroxide and peroxide, on the stability of interfacial polymer and oxide. Rotating Ring Disk Electrode (RRDE) experiments identify peroxide generation during oxygen reduction. Oxides on steel in alkaline solutions are identified in situ by a subtractively normalized interfacial Fourier transform infrared spectroscopic (SNIFTIRS) technique in a thin-electrolyte FTIR cell. The effects of oxygen reduction products on FBE coatings on steel are determined by ex-situ FTIR-RAS. The interfacial polymer and oxide are examined by FTIR-RAS after cathodic disbonding experiments. SNIFTIRS is also used in situ to monitor polymer degradation due to electrochemically generated species during cathodic protection of steel. This work is supported by the Physical Sciences Division of Gas Research Institute.