We present follow-up observations of the far-infrared (FIR) sources at 90, 150 and 180um detected as part of the ISOPHOT EBL project, which has recently measured the absolute surface brightness of the cosmic infrared background (CIRB) radiation for the first time independently from COBE data. We have observed the fields at the North Galactic Pole region in the optical and near-IR, and complement these data with Sloan Digital Sky Survey photometry, and spectroscopy where available, and present identifications of the 25 FIR sources which reach down to ~150mJy in all three ISOPHOT bands. Identifications are done by means of full spectral energy density fitting to all sources in the FIR error circle areas.