Inhaling vehicle or cigarette smoke does not invalidate fasting
27-9-2016 | IslamWeb
Question:
Assalaamu alaykum. Please let me know whether an expiation is necessary in the following situations:
1. I suffer from Waswaas (devilish whisperings) about my fast breaking due to smoke coming out of vehicles or cigarette smoke from the non-Muslims. There have been times while thinking about these thoughts, I have inhaled the smoke intentionally.
2. Once, when I was travelling, I woke up to take the pre-dawn meal and had doubts on whether the time had passed or not. Looking out of the window, I had a suspicion that the time had passed, but I still continued to eat my food.
Regards.
Answer:
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.
You should ignore this Waswaas (obsessive whispering) and not give it any attention. You should know that your fast is not broken by the inhalation of the smoke of cigarettes (passive smoking) or the smoke of vehicles as this is something that is difficult to avoid. We do not think that you deliberately inhaled this smoke and that it reached your throat; it seems that this is only Waswaas. Even if we were to presume that you deliberately did so, then some scholars are of the view that this does not break the fast. Hence, you may rely on their view as you suffer from Waswaas. If the person who suffers from Waswaas acts on the easiest view, then this removes hardship from him.
If we did presume that your fast has become void with what you mentioned, then you must make up for it and are not obliged to expiate for it because, according to the view of the majority of the scholars, expiation is only an obligation for one who breaks his fast by having sexual intercourse with his wife during the daytime in Ramadan.
As regards your eating while doubting that it is still night, then this does not invalidate your fast because the basic principle is that the night is not over, so you relied on a considerable principle and you do not have to do anything unless there is something that proves the opposite.
Allaah knows best.