I used Elmers wood filler on the inside, and the tube has a warning about eye and mucus membrane contact, but doesn't say anything about it being toxic. But lets face it, outside of the white paste we couldn't resist tasting in grade school (I mean why make it taste minty?) most glue probably has some toxicity. But covering the inside of the bowl with pipe mud should insulate the burning tobacco from the very small amount of glue showing in the crack. As far as the outside of the bowl, I don't think the heat get so hot there so as to cause toxic fumes from the CA glue. I saw this type of repair done on Reborn Pipes and I don't remember any warnings about toxic problems. Again, time will tell, and if I suddenly stop posting here, well this might be the cause.... :roll: