Look, we are at an impasse.
On 1 side, if you label everything bad, how will someone know the really, really bad from the just plain bad. And once you label everything, the label itself becomes practically worthless and people stop reading it.
On the other side, if everything is really bad, shouldn't people begin to realize this. I doubt everything in our environment causes cancer, however I wouldn't be surprised if most things man-made cause cancer. And cancer is rather prevalent, so shouldn't we be trying to become aware of why we are dying of cancer? It's possible we would attempt to curb the need for cancerous materials and we'd move towards non-cancerous solutions where possible, thereby seeing a decline in warnings. This entire thing operates on the principle of "out of sight, out of mind", if all of these things cause cancer in small doses, but they are everywhere, aren't we continuously getting cancer? If so, shouldn't we make it a conscious awareness so that people know this and act upon it?
Which brings us to the original question, if the labels are everywhere, how do we distinguish. And the answer to that is better labels. A label for asbestos that is only an issue if disturbed... should not be the same as a label for something that you'd actually get cancer for tomorrow, which should not be the same as a label that would give you cancer after a week of exposure.
"When airborn, can cause cancer"
"When ingested, can cause cancer"
It may sound dangerous to find out that your stove can cause cancer, it may not be as alarming to find out it will only cause cancer if you actually lick the inside of your stove.