IF it all passes then an enforcement date will be given. Until then, it's anyone's guess, but usually it would either be a January 1 start for enforcement or a phased enforcement date. For instance, the FDA may start by restricting commercial distribution of nicotine solution to retailers, but give retailers time to sell out their existing stock before restricting their sales. It's almost certainly not going to be an instant-enforcement situation, because that would bring on a mass of class action lawsuits by every company that would lose money. Everyone from the nicotine producers on down could file suit blocking the enforcement.
And I would be extremely surprised if ANY FDA ban isn't immediately challenged in court. Especially any policy that attempts to ban various delivery systems rather than the nicotine itself. The legal precedent to challenge such a ban already exists in the tobacco industry. Delivery systems are not banned nor even age limited. You may have to be 18 to buy tobacco, but you do not have to be 18 to buy rolling papers or a pipe. Some states have restrictions against selling delivery systems, but there is no federal age requirement to buy delivery systems, and certainly no outright ban on delivery systems.
