The Ruling on Swallowing Saliva and Phlegm, and Using Inhalers and Incense for the Fasting Person

Question:
A questioner asks: Are these things among the things that break the fast? First, swallowing saliva or phlegm? Second, using incense. Third, what remains in the mouth of the water of wudu' after rinsing. Fourth, the inhaler used to facilitate breathing for some patients.

Answer:
Saliva does not harm; swallowing one's saliva does not harm the fasting person. As for phlegm, if it reaches the throat, no, do not swallow it. If you focus on it, it invalidates the fast for the fasting person. No, blow it out. If phlegm comes from the throat or the head down to the mouth, blow it out; do not swallow it. And if he swallows it, he must make up the fast. As for the inhaler that may cause a person severe distress, the matter is... The stronger view in this is that it does not harm if he is in dire necessity for it, and it does not invalidate his fast if he is in dire necessity for it; because it is a portion of air that relieves him, and it is not classified as eating or drinking if he is in dire necessity for it.
As for incense, there is no harm in it, but one should not inhale it into his clothes or in the gathering. As for inhaling it, one should leave that, because a group of scholars hold that it is better to leave it if one inhales it. What remains in the mouth of the wudu' after the...
What remains in the mouth of the water, blow it out; do not swallow it. In rinsing, blow it out; do not swallow any of the water. As for saliva, it does not harm.