Not sure about whether it cracks plastic or not. Triacetin appears to be a humectant (used to keep things from drying out), PG and VG are apprently Humectants as well. All three can be found as additives in the list of 600 additives in tobacco cigarettes. As with PG and VG both are recognized as safe for ingestion. Also as with PG and VG, I do not think it is known for certain if there are any long term negative effects from inhalation. If someone has better information, please feel free to correct me. I am certainly not a doctor or chemist.
I do however like the fact that TFA discloses this information on their website. And also the info on "custard" ingredients.
In this thread http://www.e-cigarette-forum.com/fo...ices-flavors-crack-tanks-ce2s-clearos-40.html
Post #391 at the bottom in blue
"Perfumer's Apprentice lists triactetin as in ingredient in some of their flavors, so be sure to check that out. Triacetin has caused problems for many members."

