a. The above subject has been in the headlines in recent years, in relation to suspicions about the use of electric shavers. As is well known, the Torah forbids shaving with a razor, while one is permitted lechatchila – a priori, without any hesitation – to shave using scissors. In the Shulchan Aruch, it is written that "scissors that are like a razor" can also be used lechatchila, and that there is no dispute about this [Yoreh Dei'ah 181:10].
Thus, the central point to be determined is the definition of "scissors that are like a razor." Does an electric shaver fit into this category?
b. Until a few years ago (until the year 5761 – 2001), The Zomet Institute followed the recommendations of an article by Rabbi Shabtai Rapaport, Techumin, volume 13, page 200. He proposed as a criterion whether the blade is capable of cutting hair without rubbing against the screen that covers it. And his conclusion was that in the machines with a metal cover screen the blade alone cannot cut the hair. After the article was published, The Zomet Institute in fact issued kashrut approval certificates for this type of shaver (a blade covered by a metal screen).
c. But some doubts arose about this criterion, and we decided to review the question in greater depth. Detailed studies using close-up video photography indeed shed doubt on the previous assumptions. In an article in Techumin volume 22, we summarized the new results, including video-based photographs of the different stages of shaving.
d. The conclusion from this new study is that there is no discernable difference, from the physical or halachic point of view, between various models of electric shavers. If the "result" is what is important, all types of shavers would be prohibited for use, since none of the shavers leaves hair that can be pulled or that can be felt with the hand.
e. However, the question of whether shavers can be used is based on the definition of "scissors that are like a razor" and this depends on the mode of operation and not on the result. If the cutting is performed by two or more edges coming into contact, the machine is defined as scissors and not as a razor.
f. In all the electric shavers, the cutting process is one of contact between a moving blade and the head (a metal screen). Thus, from the point of view of the action performed, these machines are scissors. And this is the basis of our current position.
g. In addition, the current custom to remove the "lift and cut" mechanism from the shavers is hard to defend. If anything, this mechanism makes the operation even closer to that of a scissors, since it uses three elements in the cutting process: the blade, the screen, and the "lift and cut" device.
h. Companies that requested it have been given halachic approval for the specific models that were shown to us, but in principle they are no different from other shavers.
In summary: In our opinion, almost every type of electric shaver which operates as described above can be used.
For more information (in Hebrew):
Press here for a list of shavers approved by The Zomet Institute (in Hebrew).