6177– The Pasting of the Paste!
Q. Hello Rav, I work in a dental office in the frum area. Every so often a patient will ask about the kosher status of dental prophy paste used for polishing (removing plaque and stain) and Fluoride Varnish gel. Much like toothpaste, neither product is absolutely needed, but are often used to help prevent and repair tooth decay.
A. Prophy paste (prophylaxis paste) is a gritty compound used by dental professionals to polish teeth and remove surface contamination.
Although, there are those that advocate for a Hechsher on toothpaste. Currently, there is no Hechsher on any of the major toothpaste brands. Yet Kosher certificates are common for Passover use.
Rav Yaakov Kaminetsky Zt”l is quoted suggesting that toothpaste does not require a Hechsher (certification) because the glycerin within it is not a majority ingredient, and as is the majority of toothpaste ingredients consists of non-food items. Therefore, the glycerin is nullified.
Rav Yaakov elaborates that even though the Halachah requires a 60:1 ratio of kosher to non-kosher to nullify the non-kosher ingredients (Batel BeShishim), that principle only applies when both ingredients are food. A simple majority of kosher ingredients is needed to nullify the glycerin in the toothpaste. (Following the Rema, YD 108:5; and Taz, YD 98:2.).
Rav Yisrael Belsky holds that Rav Kaminetsky’s leniency no longer applies today. After researching various brands, he determined that the majority of toothpaste consists of food ingredients. In Rav Yaakov’s time, the abrasive compound calcium carbonate was the majority ingredient. Nowadays, the major ingredients are water, glycerin and sorbitol-- all food items. The abrasive ingredient has been replaced with silica. Therefore, the majority of ingredients are food-based, and Rav Kaminetsky’s leniency no longer applies.
According to many authorities, it is forbidden to taste non-kosher food, especially liquid, even if one intends to spit it out. ( This is due to the concern that one might accidentally swallow it. According to this approach, it is commendable to avoid using mouthwash that contains glycerin, an ingredient that is often derived from non-kosher sources.
Rema, YD 108:5; Taz, YD 98:2.
Rabbi A. Bartfeld as revised by, Horav Shlomo Miller, Horav Yaakov Hirschman, Horav Dovid Pam, Horav Aharon Miller, Horav Chanoch Ehrentreu and Horav Kalman Ochs Shlit’a, and Horav Dovid Bartfeld consulting, Horav Hagaon Rav Yitzchak Berkowitz Shlit’a
Reviewed by: Hagaon Rav Shlomo Miller Shlit'a
Published: November 13, 2026