Solid-containing, biodegradable ester oil based switch lubricant for the treatment of switch blades, rollers and switch control. The specially selected solid lubricant does not leave any residues and provides optimum surface wetting, even after longer usage. Special additives provide sufficient lubrication in case of long lubricating intervals. The switch oil can be applied without prior cleaning, damps mechanical pressures on switches, offers outstanding protection against wear and guarantees unobstructed function.