It may be time to end the myth about electric motors, ozone and bicycle tires. Most (all?) of the motors found in the home are brushless AC motors. They don't spark or make ozone. Of course your hand held power drill does have brushes, but isn't used enough to produce meaningful quantities of ozone. The real reason not to store tires near the furnace isn't the non-existant ozone, it's that it's the hottest place in your basement.