All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Smoking is forbidden for the reasons stated in Fataawa 81589 and 81933.
However, smoking is not an intoxicant, so it is not treated as alcohol from all aspects. Thus, we can't say that a smoker's prayers are not accepted for forty days as is the case with alcohol, for this needs an Islamic proof.
Allaah Knows best.