Diapers may be used on Shabbat just as they are used during the week. At first glance, one might think otherwise. Using a disposable diaper involves fastening tapes and then separating them. We saw earlier that one may not attach papers together on account of Tofer, and one may not separate them on account of Kore’a. However, since diapers are typically fastened using Velcro tapes that can be opened and closed multiple times, fastening them is comparable to buttoning and unbuttoning buttons, which is permitted. (One also does not need to worry about separating the Velcro when preparing the diaper for use, as explained in the note below.)
Even diapers that use adhesive tape (rather than Velcro) may be used. Since this tape is made for temporary use, many poskim maintain that just as there is no prohibition of Tofer when sewing something that will be used only for a short period of time, so too one may fasten a diaper. It is also possible that even those who prohibit sewing or attaching items for a short period of time would be lenient in the case of diapers, because the tape in a diaper is meant to be reusable, so that the diaper can be adjusted as needed. Therefore, fastening them should not be considered sewing, and detaching them should not be considered tearing. Rather, fastening them is comparable to joining items together using buttons or Velcro. However, one should be careful in one regard. During the week, when dirty diapers are thrown away, they are usually taped up using the tabs, in order to confine the contents. Since this taping is likely to last a long time, it is proper to refrain from doing so on Shabbat.
Adhesive bandages (“Band-Aids”) may be used when needed, because sticking something onto the body is not considered sewing. If necessary, an adhesive bandage can also be used to hold a cloth bandage in place, because this is meant to last only a short time. (The laws pertaining to adhesive bandages and cloth bandages are explained below in 28:9.)
One may use sticky notes to mark one’s place in a book. Since they are repositionable and designed to be used dozens of times, using them is comparable to fastening and unfastening buttons or Velcro, where Tofer and Kore’a are not concerns.
. When the diaper is closed using Velcro there is no problem at all, because Velcro is comparable to buttons. However, there are still diapers that are fastened with adhesive tapes, as was once standard. The law regarding diapers with these tapes hinges on a disagreement among Rishonim whether sewing and tearing is comparable to tying and untying. There is a principle in the laws of Kosheir that one may tie a knot if the knot will remain for a short time only, and one may untie such a knot as well. Some maintain that this permission pertains only to a knot that is designed to last under 24 hours, while others extend it to a knot that will last under a week (Rema 317:1). In a time of need, we follow this lenient position (BHL 317:4 s.v. “she-einam”). If it is a knot that will last until the item’s owner or buyer comes to retrieve it, Levush 317:3 explains that even if it ends up staying tied for more than a week, the knot is considered impermanent. Thus one may tie and untie it. This is the accepted ruling (see below, n. 10).According to Rabbeinu Yoel, Raavya, Rashbam, and others, this rule applies to sewing and tearing as well, and there is no prohibition of sewing when it will only last a short period of time. However, according to Rabbeinu Peretz and Mordechai, such sewing is rabbinically forbidden. R. Yosef Karo is stringent in SA 340:7, though it would seem that he is lenient in Beit Yosef 317:3. Tehila Le-David 340:6 resolves the discrepancy by explaining that R. Karo is stringent regarding Tofer but lenient regarding Kore’a; he also believes that this is the position of Rema. Others maintain that Rema is lenient regarding Tofer as well as Kore’a (SSK). Accordingly, following those who are lenient, one may fasten the tapes of a diaper and undo them, because this attaching is done for the short term, while for those who are stringent this is prohibited. Yeĥaveh Da’at 6:24 states, based on a number of Aĥaronim, that the halakha follows those who are lenient, and therefore one may use diapers with adhesive tapes. Another strong rationale for being lenient is that since the tapes are made so that they can be opened and closed multiple times, fastening them is not considered sewing. Rather, they are similar to buttons or Velcro, which may be used to connect and disconnect parts of an item of clothing (Orĥot Shabbat 11:36).
As far as opening the tapes initially so that one can then fasten the diaper, based on Levush and those who rule like him (as explained in n. 10), one may open them even though more than a week has gone by since they were taped shut in the factory. Additionally, the taping done in the factory is not considered attaching because the intention is not to connect two items, but rather to prevent the adhesive from drying out (SSK 35 n. 67; some are stringent and make sure to open the tapes before Shabbat).
After removing a dirty diaper, it is proper to avoid sealing it with the tapes, because this seal is intended to be permanent. Even so, I only wrote “it is proper” in the main text, because if we consider the tapes comparable to a button, there is no prohibition involved. Additionally, according to R. Shlomo Zalman Auerbach (cited in SSK 35 n. 67), since one only cares that it stays closed while it is in his garbage pail, this is considered a short-term seal.