i get this to jus lil grey bits i cough up, i only use a volcano an the odd bong hit but thats like once a month on a bong, avge 6 vapes a day. i dont cough up tar or anything else jus lil grey sometimes blackish stuff.
ive looked loads online for an answer but cant find shit.
peronally i think it could be lung tissue because of how cannabinoids or thc acts on the lungs forcing damaged cells to die an regenerate instead of mutating. so i am having to cough up the damaged cells/tissue.
it seems to be more common with people that only smoke weed pure or vape it not those who smoke cigs or other shit they seem to get tar an green shit aswell.