In the beginnings of mechanical refrigeration, at the end of the nineteenth century, carbon dioxide was one of the fi rst refrigerants to be used in compression-type refrigerating machines, later gaining widespread application mainly onboard refrigerated ships, but common in other sectors of refrigeration as well. It was only immediately after World War II that CO 2 was rapidly eclipsed as a refrigerant, due to the advent of the synthesised halogenated working fluids, addressed as safe and ideal refrigerants at that time. Copyright , Manchester University Press.