The invention is a process for producing a white oil having an initial boiling point of at least 250° C., the process comprising a step of catalytically hydrogenating a base oil feedstock at a temperature of from 120 to 210° C., at a pressure of from 30 to 160 bars and a liquid hourly space velocity of 0.2 to 5 hr−1, the base oil feedstock comprising less than 5 ppm by weight of sulphur.