it would not be likely to get brain damage from smelling a polyester backpack although i have encountered some deadly tennis shoes from time to time. you are safe.
i was smelling a 100% polyester backpack to see if it needed to be washed. i got a headache can this cause brain damage? . i'm known to be a hypochondriac. can catching a few whiffs of this 100% polyester cause any short term long term brain damage or am i worrying about nothing?