Answered by Shaykh Amjad Rasheed
Does using toothpaste invalidate one’s fast?
Answer:
السؤال : هل استعمالُ معجون الأسنان مبطلٌ للصوم ؟ الجواب : استعمال معجون الأسنان لا يبطل الصومَ إلا إذا وصل منه شيءٌ إلى الجوف .
Using toothpaste does not invalidate one’s fast unless some of it reaches the body cavity.
[Thus, one should exercise due precaution, and try to avoid using toothpaste while fasting. If one uses it, one should rinse out one’s mouth properly.]
Amjad Rasheed
[Translated by Sr. Shazia Ahmad]