At present There exists some controversy bordering using this substance in vapor products, although no concrete proof has emerged to explicitly label it as unsafe. There has been dialogue of acetyl propionyl resulting in harm to the respiratory tract, and it's been known to harm the lungs in research http://coilhunnyeliquid7096.pointblog.net/burst-duo-eliquid-guava-dragonfruit-1175-Things-To-Know-Before-You-Buy-33089292