most mason jar lids contain BPA (which may or may not be as bad as the rap it is getting these days, the jury is still out). But when you heat that BPA you volatize it releasing it to the surrounding air/bud.
This technique of heating the lid WILL increase the seal and allow for longer shelf life, but it MAY kill you slowly
http://www.treehugger.com/green-food/is-there-bisphenol-a-in-your-home-canning.html
your kidding right?Smoking pot will kill you slowly..
mgk