Answer
Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
If an external object gets into the mouth, one should spit it out and not swallow it. Thus, brushing teeth, gargling water or mouth rinse, and even using toothpicks will not invalidate fasting as long as they are not swallowed and enough effort has been spent to eject those materials outside the mouth.
Responding to your questions, the Islamic Religious Council of Singapore, states:
There are many hadiths about things that invalidate fasting and its integrals. You may wish to refer to them in books that discuss fasting in details.
However, we would like to point out that fasting will not be invalidated as long as an external object does not reach the most internal part of our open organs, which are mouth, nose, ears and private parts.
With regard to the mouth, if an external object gets into the mouth, one should spit it out and not swallow it.
Thus, brushing teeth, gargling water or mouth rinse, and even using toothpicks will not invalidate fasting as long as they are not swallowed and enough effort has been spent to eject those materials outside the mouth.
With regard to the nose and ear, if an external object enters it but remains close to the opening, then fasting will not be invalidated. But if the object goes deep into the nose and ear, fasting will be invalidated.
Allah Almighty knows best.
Editor’s note: This fatwa is from Ask the Scholar’s archive and was originally published at an earlier date.