Whhhaaa? Your numbers dont make sense. Do you mean 10:1?
Id say you are really flooding your engine with fuel. Whether its safe or not is debatable. If that was at idle Id say I wouldnt be running a car like that since the issue is that with that much fuel being dumped into your combustion chamber it can actually wash the cylinder walls off oil and eventually the pistons will score the walls.
However, if its at WOT then I wouldnt say you are doing any damage. YOu either need to get a tune or get rid of that ECU since its just eating fuel and costing you power.