May one tear a piece of glad-wrap from the roll on Shabbos?

Destructive tearing on Shabbos is merely an issur d’rabanan but constructive tearing on Shabbos is an issur d’oraisso (a biblical violation). [1]

The M”B writes [2] that tearing paper in order to use the torn pieces is a beneficial tearing and hence it would be an issur d’oraisso. [3]

Accordingly, tearing a piece of Glad Wrap or aluminum foil from the roll infringes on an issur d’oraisso and may not be done on Shabbos for any reason. [4] However, tearing open the glad wrap that is covering a bowl of salad is totally permitted as one is destructing the glad wrap and it is being done in order to be able to attain the contents of the bowl and not for the sake of tearing the wrapping.

This latter halacha is learned from a Tosefta [5] that teaches us that one may rip the leather covering a barrel in order to reach the wine.

What about tearing toilet paper when there is no option?

Obviously one must prepare toilet paper before Shabbos. The problem arises when one has depleted the supply of tissues, torn toilet paper etc. or one is in a place where there is no pre-torn paper.

For obvious reasons we will not discuss the various technical options that are on hand when there is no toilet paper available, but when those options are exhausted and/or one’s only practical option is uncut toilet paper, the following is the correct procedure:

One should tear the toilet paper by resting one’s elbows on the sheet of toilet paper and tear it with one’s elbows. This is called tearing kilachar yad – in a backhanded manner, and is only an issur d’rabanan. [6]

Where do we find that one may violate an issur d’rabanan in such a case?

There are two sources. The Rama says [7] that one may carry stones (olden day toilet paper) from a reshus hayachid (a private domain) into a karmelis even though one is violating an issur d’rabanan. The basis for this heter is that Chazal did not institute their prohibition when it confronts a person’s dignity - 'kavod habriyus'.

The other source is the Mechaber [8] who permits one to raise a stone that has moss growing on it even though raising it from the ground is a violation of an issur d’rabanan.

This therefore is the basis for this heter.

Does it make a difference whether toilet paper is torn on the dotted line?

In order to answer this question we must, in a few words, familiarize ourselves with the melacha called Mechatech – tearing or cutting to an exact size or measurement.

'Mechatech' is the melacha of cutting or tearing an item for a specific purpose or size. An example of this is a gemora which says that one who purposely breaks the feather between the soft part and hard part has violated Mechatech. The soft part would be used for down and pillows and the hard part would be used for hat manufacturing. Since one is particular about breaking the feather at that exact point, it is mechatech.

Based on this and many other proofs we can determine that although tearing toilet paper involves Kore’ah and maybe even “making a k’li”, tearing on the dotted line is probably not Mechatech. Rav Shlomo Zalman Auerbach explains [9] that since one only tears on the dotted line because it is a convenient manner of tearing the paper but not because one is particular about the exact size of the paper. Proof of that is that each paper company has a different size paper and nobody buys paper because company A has paper size B.

This means that one may only tear paper backhandedly, as mentioned above, when there is no other feasible option, but one need not be particular about not cutting on the perforated line.

However, we do not find this opinion mentioned in other poskim and therefore, if possible, one should avoid tearing on the perforated line.