July 14, 2024
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July 14, 2024
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Hard to Swallow: Controversies 

Over Kashrut of Contemporary Toothpaste

May this special post be an ilui neshama (merit for the soul) of my dear mother, Mrs. Joan Maybruch, Yocheved Pesha bat Hillel, z”l, on her yahrzeit.

Is Kosher Toothpaste a Paradox?

What’s in your toothpaste? Chances are that glycerin is listed as one of the ingredients. This syrupy, sweet liquid can come from plant sources but often is derived from non-kosher animal sources. How can one explain the widespread practice to use toothpaste without checking the glycerin source or looking for a specific kosher supervision?

There are two possible reasons that toothpaste might not need to be kosher. Firstly, it isn’t swallowed. Secondly, it is not a food that is normal to eat altogether. Are these reasons enough to obviate the need for kashrut? It might depend who you ask throughout the centuries.

Tasting a Non-Kosher Food Without Swallowing

The first issue, relying on not ingesting the toothpaste, hinges on a responsum of the Rivash (1326-1408 CE, Responsum 288). He maintains that it is rabbinically prohibited to taste non-kosher and expectorate it. The Sages wanted to ensure that a person would not mistakenly swallow non-kosher, so they added a restriction on tasting too.

At the same time, a fascinating leniency is advanced by Rav Menachem Mendel Krochmal of Nikolsburg (1600-1661 CE) in his responsa Tzemach Tzedek (Responsum 47). He was asked about the permissibility of a soaper tasting his soap to check the ingredient proportions. The soap contained non-kosher fats, as well as ashes and lime. Although it was not a foodstuff, since it contained non-kosher it might be prohibited to taste.

The Tzemach Tzedek rules leniently. He explains that soap is not fit for human consumption. The Talmud (Avoda Zara 67b) rules that a prohibited food that becomes inedible is no longer biblically forbidden. Yet, it is still rabbinically prohibited. In addition, as the Rivash stated, tasting a prohibited food without swallowing it is also rabbinically prohibited.

The Tzemach Tzedek rules that those two rabbinic prohibitions combine to create permissibility. While the Sages prohibited ingesting inedible food, they did not prohibit tasting it without swallowing. Full consumption of an inedible food is rabbinically prohibited, but the Sages did not prohibit mere tasting of it. Therefore, the soaper may taste his soap.

Don’t Swallow!

The Noda B’Yehuda (YD 52) clarifies the ruling of the Tzemach Tzedek. He theoretically accepts the permissibility of tasting non-food items. Yet, he is concerned that it is almost inevitable that one is going to swallow some of it. Consequently, the Noda B’Yehuda maintains that when the Tzemach Tzedek wrote that one is allowed to taste an inedible food, he only meant to permit tasting it with his tongue, which will not lead to ingestion. The Tzemach Tzedek concurs that putting a non-kosher food in one’s mouth fully is still prohibited because it is inevitable that he is going to swallow some of it.

The Pitchei Teshuva (YD 88, 1) quotes the Noda B’Yehuda and disagrees. He maintains that when the Tzemach Tzedek permits tasting inedible food, he even means inserting it fully into his mouth. It appears that the Pitchei Teshuva is not concerned about the minute amount a person may swallow. Since the prohibition of eating inedible food is rabbinic, the Sages did not include ingesting a minute amount while tasting in their prohibition.


This dispute has direct relevance for using toothpaste. Toothpaste contains abrasives, such as hydrated silica. This substance renders the toothpaste on the whole a non-food item. If it would contain animal glycerin it still would be rabbinically prohibited to eat, like any other food that is rendered unfit for consumption.

Consequently, it falls into the dispute between the Pitchei Teshuva and the Noda B’Yehuda. In the view of the Pitchei Teshuva, one may put it into his mouth and then dispose of it. Even if it is inevitable for him to swallow some of it, that minute amount was not prohibited by the Sages. However, according to the Noda B’Yehuda, putting non-food items in the mouth past the tongue is prohibited. Therefore, one might not be able to use toothpaste that contains glycerin. Since toothpaste is a non-food that is rabbinically prohibited, he may not brush his full mouth with it because it is inevitable that he is going to swallow some of it.

Rocky Ground

The second approach that one might advance to allow using toothpaste containing glycerin is the rule of nullification. Halacha states that if a non-kosher substance is mixed with a kosher food, the mixture may be eaten if there is a ratio of 60:1 of kosher to non-kosher (Shulchan Aruch YD 98). That ratio of neutral items to glycerin does not usually exist in toothpastes.

Yet, Rav Yaakov Kaminetzky (recorded in the footnote to Emet L’Yaakov YD 103) uses an intriguing and novel idea to permit toothpaste with glycerin. He states that in most cases of halachic nullification, a proportion where the kosher food is in a simple majority to the prohibited food is permissible. Halacha only demands a proportion of 60 in order to obliterate the flavor of the non-kosher food.

Rav Yaakov maintained that in non-food items, a simple majority is always sufficient. Since it is a non-food, the addition of flavor by the prohibited food is irrelevant. Therefore, there is no need to have a 60:1 ratio. Consequently, Rav Yaakov would say that as long as toothpaste is less than 50 percent glycerin, it is permissible. It is a non-food item and only needs a simple majority to nullify the glycerin.

Not Too Abrasive

There are different approaches regarding if Rav Yaakov Kaminetzky’s fascinating leniency applies to contemporary toothpaste. When Rav Yaakov issued his ruling there was a large amount of abrasive (originally calcium carbonate) in toothpaste. Toothpaste was mostly tiny pieces of mineral rock, with some glycerin, water and other ingredients added. Rav Yaakov even refers to toothpaste as “stone.” In that toothpaste, the abrasive alone was enough to outnumber the glycerin; it was a direct majority in proportion to it.

More recently, the American Dental Association advocated severely reducing the amount of abrasive in toothpaste. The abrasive (now commonly hydrated silica) is much less prominent as an ingredient. It usually takes up no more than 20 percent of the volume of the toothpaste and does not have enough volume to halachically counteract the glycerine. Yet, aside from the glycerin and abrasive, the toothpaste contains halachically and gastronomically neutral ingredients such as water, fluoride and flavorings. The volume of all the other ingredients compared to the glycerin is still greater than 50 percent, even though the abrasive alone does not outweigh it. Since the abrasive doesn’t outnumber the glycerin, but the ingredients combined still do, may one use Rav Yaakov’s leniency that non-foods needs a simple majority?

Some major American kashrut organizations maintain that Rav Yaakov Kaminetzky’s leniency would not apply anymore. They explain that because many of the other ingredients in toothpaste are easily ingestible and the non-food abrasive does not directly outweigh the non-kosher glycerin, Rav Yaakov Kaminetzky would no longer say that a simple majority against the glycerin is sufficient.

One might advance a different approach. Although the direct ratio of abrasive to glycerin has greatly changed, toothpaste is still fundamentally a non-food. The addition of even a small amount of silica, a mineral rock, still makes us group toothpaste as a non-food item. Since it is a non-food, it would still governed by Rav Yaakov Kaminetzky’s principle that in non-foods a simple majority outnumbering non-kosher is enough to permit it. In toothpaste, the abrasive and halachically neutral ingredients join together to create a simple majority against the glycerin, rendering all toothpaste kosher.

By Rabbi Shmuel Maybruch

 Rabbi Shmuel Maybruch, LCSW, is a psychotherapist who focuses on dating, marriage and family relationships. He practices at The Relationship Couple, LLC, in Passaic, New Jersey, and online. A longer version of this article originally appeared on his blog, ShmuelMaybruch.com, which focuses on the interactions of Judaism, psychology and psychotherapy.


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