Smoking is haraam and invalidates the fast

Some people say that fasting is not invalidated by smoking; because it
is not food or drink. What is your opinion about this?.
Praise be to Allaah.
I think that this is a view for which there is no basis. Rather
smoking is a kind of drinking; in Arabic they say that one "drinks"a
cigarette. Moreover, there is no doubt that it reaches the stomach and
the inside of the body, and everything that reaches the stomach and
the inside of the body invalidates the fast, whether it is beneficial
or harmful, even if a person were to swallow a bead from the masbahah,
or a piece of iron, or anything else, it invalidates the fast.So it is
not essential that the thing that invalidates the fast, or that is
eaten or drunk, should be nourishing or beneficial. Everything that
reaches the stomach is regarded as food or drink. They believe –
indeed they know – that this is a kind of drink, and if anyone says
this then he is being arrogant.
Moreover, I think that the month of Ramadaan is an opportunity for the
one who is sincerely resolved and wants to give up this foul, harmful
habit of smoking. I think that it is an opportunity because he is
going to abstain from it throughout the day in Ramadaan, and at night
he can distract himself from it by means of the food and drink
thatAllaah has permitted to him, and by frequenting the mosques and
attending gatherings of righteous people, and he can keep away from
thosewho have this habit. If he abstains from it throughout the month,
then that will be a great help to him in giving it upfor the rest of
his life. This is an opportunity which smokers should not miss. End
quote.
Majmoo' Fataawa Ibn 'Uthaymeen, Fataawa al-Siyaam