Humans didn't evolve inhaling butane, unless the data-sheets also reference multiple studies based on large, diverse data sets going over several decades......then the health risks of inhaling vaped butane repeatedly over a period of time are completely unknown! ....this is what basic science says, if the manuf says different they are talking out their ass, but I suspect your manuf quotes relate to a very narrow generic test which has nothing to do with the practice of vaping bho.
But as you say there are known general health risks with Butane, so we do know it's not completely innocuous not even close.
If you're not getting the adverse symptoms of headache, nausea, dizzines, etc., then you're not getting anywhere near any kind of harmful level, and again,
You can't state that as fact, nor is it workable, what do you do once you have the adverse symptoms? there is no rewind button & some of the symptoms could be caused by mj, so
knowing the
dizzines you're experiencing is
from the huge dab you've just had or is it down to the butane in the dab product itself or maybe it's a bit of both? it's difficult to know for sure & thats before we get to the fact the observer is wasted....goes without saying it will be near impossible for any meaningful science-led data collecting on the subject.
There will also be a ramp-up:
0-->adverse symptoms, what are the effects of being subjected to this ramp-up daily over a period of years( if bho is your thing )? ...again no one knows, unless someone can provide links to multiple *studies based on large, diverse data sets going over several decades.
*studies dealing with bho specifically not unrelated, so no
A = B so B must also = C or thats-true-so-this-must-also-be-true type studies or popular journalistic articles about studies or youtube videos
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The thing I don't understand about this topic is why so many people seem resistant to Butane free concentrate?
Good BHO can be produced with very tiny amounts( 5-10ppm) of Butane, if the consumer continues to demand clean product and votes with their dollars then clean product & techniques to make(&test) clean product we shall have.