Death by Tights

I would presume if a fat lady wearing a pair of tights was to sit on your face its Death by Suffocation, because surely the toxicity content (cytotoxic) depends on the time scale she has worn them.
Now I'm no expert in tight hygiene, but surely a large lady sweats a lot and hose change over should be at least half daily.
Now had she worn them for several days to increase the potency surely a swarm of flies would be a sure indication of the woman's intent.