this topic comes up every once n' a while..
i think i may have even posted this link once before...
it's a study with dichlorvos, obviously you don't want to sit there with the strip hanging over your head if you can avoid it. dichlorvos is most dangerous to people/insects/etc when it reaches certain kill level in your system..as you can see with ventilation on, it can't even kill a mite. but when it's allowed to build up...they are dead.
if you read the above link you will realize that they use this chemical to control bugs on the food you eat.. and it has a half life of about 2 days or so...i'd say 2 weeks before harvest, take the strips out.
used with a brain, it's ok,
smoking the hot shot pest strip ... not so good.