FlavourArt of Italy are testing their flavors for cytotoxicity, comparing, in vitro, the toxicity on lung cells.
They have also removed all diketones such as diacetyl from their Vape Heaven line. This means that many 'buttery' types of flavors will not be available in the vapable line until safe substitutes are found - which could be a long time. Their position seems to be that there are currently no safe versions of this type of flavor.
ClearStream Protocol - FlavourArt - The Flavors tailors