Igros Moshe (CM II #18) Question: Is it possible to prohibit smoking in yeshiva and synagogue where there are people who are very bothered by the smoke and it causes painful headaches and other pains and physical problems and health issues and possibly shortens their lives.? Answer It is well known that cigarette smoking is harmful to many people. It is clear and obvious that even without concern for actual danger and illness, the mere fact that it is irritating and disturbimg to some people is enough reason to prohibit smoking in yeshiva and synagogue and all places where there are people who are bothered by the smoke even if it causes bitul Torah for the smoker. .
Igros Moshe (C M II #76) Question: Is cigarette smoking prohibited? Answer Even though there is a principle that G-d (Shomer Pesaim) guards the fools from harm when they do something dangerous. Nevertheless it is normally prohibited to rely on it Furthermore it is obvious that concerning an issue in which there are many people that it doesn’t harm their health at all such as types of food that many people enjoy such as fatty meat or sharp spices while for certain people it is harmful. Nevertheless we don’t prohibit the food for everyone. Everyone should avoid food that is not healthy for him. While you work in a hospital and therefore you see many more people who are sick from cigarette smoking than an average person sees in the normal population, nevertheless the amount harmed by cigaretts is still a minority. In this situation we do apply the principle of Shomer pessaim. Nevertheless it is definitely best that everyone, especially Torah students – not to smoke since there is a factor of danger and no genuine benefit to those who are not habitual smokers. It is best not to become used to smoking especially a father should not let his son smoke even if he himself smokes. Aside from the problem of addiction to cigarettes they should be avoided since a person should not seek after extra pleasures
Igros Moshe (YD II #49) Question :Is smoking cigarettes permitted? Answer Since there is concern that this makes you sick it is best not to smoke. However to say this is prohibited as dangerous is not possible since the danger is widely ignored and thus we say shomer pessaim. In particular since many gedolim in previous times smoked and the present generation smoke. Therefore even those who are strict because of danger, there is no prohibition of lifnai ivair to offer a light or match to the cigarette smoker
Igros Moshe (OC V #34) Question: Is it permitted to smoke on Yom Tov? Answer Many Poskim have discussed this at length. In reality it is a widespread practice and most smokers are lenient. In practice while there are many who don’t smoke because it is viewed as a harmful practice. And thus it loses the status of being the same for everyone but it is difficult to rule against what is an accepted practice, whether because of danger or some other reason, since even in previous generations not everyone smoked. In additiom since there are 100s of million people who smoke and that makes the practice considered equal for everyone. Therefore even though it is definitely best for a baal nefesh to be strict and not smoke on Yom Tov. It is difficult to say it is prohibited