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Shabbat Parashat Emor| 5766

Ask the Rabbi

Question: Is it permitted to put on strips that whiten the teeth on Shabbat?
Answer: Let us make sure that we are referring to the same thing. Home-use, teeth-whitening strips are adhesives similar to a band-aid with an active ingredient of peroxide or another bleaching agent. One uses each one for about half an hour per day and the treatment, lasting a couple weeks, causes the teeth to be significantly whitened.
 We must investigate two melachot (categories of forbidden work on Shabbat) regarding whitening teeth. One is melaben, which is literally, whitening. The other is tzoveiah, coloring.
 Classic melaben, as found in the mishkan,was the whitening of wool, done by removing the impurities that got on the wool while it was on the sheep. The toladot (Torah-level extension of the melacha) apply to washing different fabrics. However, melaben does not apply to hard objects that do not absorb (Mishna Berura 302:41), including teeth.
 Tzoveiah applies to the coloring of even hard objects. If the color lasts for a long time, there is a Torah-level prohibition, and if for a moderate amount of time, it is forbidden only rabbinically (see Rambam, Shabbat 9:13 & “The 39 Melochos,” pg. 740). In any case, the teeth whitening lasts for a relatively long time. One factor that limits the applicability of tzoveiah here is the fact that the colored object is the human body. R. Eliezer and Rabbanan (Shabbat 95a) argue if it is forbidden from the Torah to color the human body. We accept Rabbanan’s opinion that it is not a Torah prohibition (Rambam, Shabbat 22:23- see Minchat Chinuch 32:16). However, there is still a rabbinic violation. Therefore, for example, it is forbidden for women to put on many types of makeup on Shabbat.
 Is whitening teeth (which is done chemically) analogous to adding a layer of color to the surface? Acharonim assume that it does not make a difference how an action causes an object’s color to change. For example, the Minchat Yitzchak (V, 32) says that one may not purposely suntan on Shabbat, because it brings about an intentional coloring of the skin. Similarly, while most poskim allow going outside with photo-gray lenses (which get darker in brighter light), they do not base themselves on the fact that the change is chemical (see Shemirat Shabbat K’hilchata 18:18). A Talmudic basis for this concept exists in Rashi’s understanding of the mishna (Shabbat 94b), which is accepted as halachaby the Shulchan Aruch (OC 303:25). There it prohibits placing a type of dough on the skin that causes a red mark to develop.
 One might argue that bleaching is not coloring but neutralizing “impurities” and allowing the white, which indicates the absence of elements that absorb light, to remain unhindered. However, this is apparently not a correct halachic analysis. The strips do not scrape off particles and allow a lower, white layer to be visible. Rather, they chemically alter the normal color of one’s teeth to a brighterthanusualshade of white. How one changes an object to any color, including white, is halachically unimportant. It is even possible that removing a layer to uncover a desired color below is tzoveiah  (so implies “The 39 Melochos,” pg. 749). Another lenient claim might be that a single application of the strips does not make a noticeable difference. It is true that it takes more than a week for the full impact. However, our understanding is that each application is hoped and expected to have some effect and that not all cases progress at the same pace. Since the user’s intention and not all cases are the same, it is hard to use this as a source of leniency.
 Therefore, we believe that one should not use the teeth-whitening strips on Shabbat, which should not be an impediment to completing the treatment. (We did not deal with the issue of using adhesives that must be removed from their base. This is similar to issues regarding diapers and band-aids (see instructions in Shemirat Shabbat K’hilchata 15:81 and 35:20-28)). 
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This edition of
Hemdat Yamim is dedicated to the memory of
R’ Meir ben Yechezkel Shraga Brachfeld o.b.m.
Hemdat Yamim is also dedicated by Les & Ethel Sutker of Chicago, Illinois
 in loving memory of Max and Mary Sutker and Louis and Lillian Klein,z”l.
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