Not exact matches
But they dropped caffeine from their list of prohibited substances in 2004 because caffeine is so ubiquitous that setting a threshold might lead athletes to be penalized for what others would
consider normal caffeine
consumption.
There is no set number, but as a rule of thumb, it's often agreed that up to about 1 quart or 1 litre of oil per 1000 miles (e.g. out of 6L of oil from the oil pan) is
considered to be an entirely
normal oil
consumption rate; on the other hand, more than 1L per 1000 km is probably too much of an oil
consumption.
As others mentioned, this is not to be confused with oil leaks, where the oil leaks onto the ground from beneath the engine — no such oil
consumption should be
considered as
normal.
In short, and you've heard TreeHugger and many others say it before, but it bears repeating: There are simply not enough resources on the planet to extend what is
considered a
normal, even essential, level of material
consumption in wealthy nations to a planet with 6 billion and growing people: Resource Use Increasing Faster Than Population
Consider some stats.
The amount of natural resource
consumption that is
considered normal in the developed world, and is aspired to in the developing world, is entirely unsustainable from an ecological standpoint.