Shaykh Ibn Uthaymeen was asked:
You find some people, specifically employees, that they use very strong fragrances when they want to leave the house. They use a mouth spray to improve the breath after long sleep after Fajr. So what is the ruling on that, may Allah facillate for you good?
“Then there is no harm in a fasting person using a good scent, whether that be on his head, beard, or clothing. As for using mouth sprays, then there is no harm in this also if it does not reach the stomach. As for if it reaches the stomach, then it is not a must to use it for that will expose him to breaking his fast. If the spray does not pass the mouth, then there is no harm in using it to freshen his mouth or use it to make breathing easy for him as some people are afflicted with asthma and the likes. I love that the one who uses this spray to freshen his mouth return to the doctors because I heard that the result of using a freshener in the mouth is vapor and a foul smell in the mouth. So it is necessary not to use that when fasting or other than it until he asks the doctors. And Allah is the one who facilitates”
[Noor ‘ala Darab no. 74]
Faisal Ibn Abdul Qaadir Ibn Hassan