Part I

Reactions abound to the “Halachic Haircutting Handbook,” we released in June 2021, especially to our strong support of Rav Hershel Schachter and Rav Mordechai Willig’s baseline permission of all electric shavers. We document that the Chochmat Adam, Chafetz Chaim, Kitzur Shulchan Aruch, Aruch Hashulchan and Rav Moshe Feinstein all permit a misparayim ke’ein ta’ar (scissors like a razor) that leaves a clean shave (although the Chatam Sofer and Chazon Ish disagree). Therefore, electric shavers are halachically permissible according to the consensus of poskim. We argue that all electric shavers function as a “misparayim ke’ein ta’ar,” making testing individual models and shavers unnecessary for halachic permissibility. According to the Chochmat Adam, Chafetz Chaim, Kitzur Shulchan Aruch, Aruch Hashulchan and Rav Moshe Feinstein, all electric shavers are permissible. According to the Chatam Sofer and the Chazon Ish, all are forbidden unless special modifications are made to the shaver to ensure it does not leave a clean shave.

This week, we present five critiques of our assertions, followed by our responses:

Critique No. 1

Pressing an electric shaver against his skin for a few seconds will cause skin abrasion. This indicates that if one presses the electric shaver against one area for a few seconds, the blade will touch the face, causing the abrasion. If the shaver blade touches the face, it cuts hair like a razor and is forbidden. The remedy for this concern is to disable the lift blade.

Response to Critique No. 1

Upon consultation with a top engineer who specializes in electric shavers, it turns out that facial skin is flexible and—in atypical circumstances—under pressure, can move into the openings of the electric shaver screen, and superficial facial skin contact ensues.

Nonetheless, this phenomenon does not pose a halachic problem for three reasons: First, the concern for the shaver blade touching the skin appears not even close to a miut hamatzui, a sizable minority of cases. A “miut hamatzui” is generally accepted to be occurrences of more than 10% (Teshuvot Mishkenot Yaakov 1: Yoreh Deah 17, Teshuvot Minchat Shlomo 2:61:1, and Rav Hershel Schachter’s Nefesh HaRav page 228; Rav Mordechai Willig agrees). We—and several people to whom we have spoken—have never experienced such an abrasion when shaving. This occurrence is nowhere near 10% and is dramatically lower. A situation of rare occurrence does not merit halachic concern. In addition, one does not intend such abrasions to occur, which are not inevitable. Therefore, they fall into the category of a davar sheino mitkavein (an unintended act), which the halacha permits.

Second and most important, the Philips-Norelco PowerPoint shows the shaver blade cannot cut facial hair without the partnering of the screen. Thus, even if the shaver blade touches the skin, it cannot cut hair and does not function as a ta’ar (razor). Even if the skin is pushed into the screen, the skin still cannot provide enough counterforce due to its large angle, as we shall explain later. Instead, the screen offers the counter force through the skin.

As an analogy, batting gloves cannot hold onto a baseball bat on their own. They are too flexible and floppy. Human hands, though, are rigid enough to clasp onto a baseball bat. So even if those hands have gloves around them, it’s not the gloves providing the force to hold up the bat, but the hands inside. So too, it is still the screen working in tandem with the spinning blades that is making the cutting action—not the spinning blade and the skin.

Finally, all electric shavers are forbidden if one does not accept these two points. The prominent engineer we consulted told us that disabling the lift blade does not affect the shaver blade from touching the skin.

Critique No. 2

Permitting electric shavers violates the Gemara’s (Kiddushin 57b) principle of “Shelach l’takala lo amrinan—we do not release a forbidden item into circulation, lest we cause someone to stumble unknowingly,” into a Torah prohibition due to the concern raised above.

Response to Critique No. 2

“Shelach l’takala lo amrinan” applies only to a forbidden item, such as non-kosher food or clothes that contain shatnez. However, it does not apply to an electric shaver whose blade rarely touches the skin. Moreover—as explained—the concern does not reflect the reality of how electric shavers work.

Critique No. 3

The Philips-Norelco PowerPoint concludes that facial skin does not provide sufficient counterforce for the electric shaver blade to cut facial hair. Therefore, electric shaver blades cannot cut without the screen’s partnership. The critique is that the argument is invalid. If a razor blade cuts independently against the skin, electric shaver blades can do so. There is concern that the electric shavers will (especially at high speeds) function as a razor if the blade is sufficiently sharp.

Response to Critique No. 3

Manufacturers design razors to function differently than electric shavers. For an explanation of how razors cut, please see https://www.asharperrazor.com/the-physics-of-shavingcutting-hair. The Norelco PowerPoint, videos and the patents we reference in “Halachic Haircutting Handbook” show that electric shavers are engineered to work very differently than razors. Manufacturers plan for them to work like scissors. Gillette summarizes the points at the following link: https://gillette.com/en-us/shaving-tips/how-to-shave/wet-dry-shaving-comparison-razor-vs-electric

The Philips-Norelco PowerPoint shows that electric shavers are engineered to only cut in tandem with the screen (i.e., like scissors or misparayim). Dr. Allan Zarembski—a world-class University of Delaware professor and director of the Railway Engineering and Safety Program (with considerable expertise regarding metal function)—agrees with our assessment. More to be explained later …

Critique No. 4

The videos from Philips-Norelco only prove that the models shown in the video act scissor-like. However, we need a video of every variation of electric shaver to clarify it works like a misparayim.

Response to Critique No. 4

The patents for all shavers have been consistent since the 1940s. Martin van Veen—a top engineer from Philips-Norelco—clarified in 2020 that they are expected to remain the same for at least the next two generations of electric shavers (that are in the development pipeline). The videos indicate a broader pattern of how all electric shavers work. Mr. Van Veen wrote to us that all Philips-Norelco electric shavers are designed to cut hair in a scissor-like manner. Mr. Mark Hafter wrote the same about Gillette electric shavers. The Gillette website also presents all electric shavers as functioning as scissors and not as razors (https://gillette.com/en-us/shaving-tips/how-to-shave/wet-dry-shaving-comparison-razor-vs-electric).

The halacha legitimates two experts independently verifying information (see Gittin 19b).

Electric shavers functioning effectively for 10 years or longer without significantly diminished performance shows that they are not designed to cut by their sharpness (which reduces over time), as opposed to razors whose blades need frequent replacement. Razor blades need replacement in weeks; electric shaver blades last over a decade. The blades’ sharpness is irrelevant to the functioning of an electric shaver.

Rav Hershel Schachter told us that if the shaver blades that Rav Moshe Heinemann and the Star-K determine are too sharp continue to function even after one dulls the shaver blades, it shows that the shaver blades—despite being sharp enough to cut a beard hair—are designed to work as scissors and not as a razor. It seems far-fetched to say when they are sharp, they function as a razor, but when dulled, they function as scissors.

It seems unreasonable to be concerned that a machine deliberately designed to cut like scissors would deviate from its intended design and act like a razor. Halacha does not consider occurrences that differ from the norm, achzukei rei’uta lo machnikinan (e.g., Shulchan Aruch Orach Chaim 467:3 and Yoreh Deah 52:3).

Critique No. 5

Rav Moshe Feinstein required checking if the shaver blades could cut a hair, and we may not deviate from Rav Feinstein’s ruling.

Response to Critique No. 5

Rav Schachter said that Rav Moshe Feinstein’s testing if shaver blades can cut a beard hair held in hand—followed by Rav Heinemann—was only necessary before we had clarity from the manufacturers regarding how electric shavers work. With all the information we now have from Gillette and Philips-Norleco and other sources—such as reviewing the patents—we have no reason to doubt that all electric shavers function as scissors, as per their intended design.

Moreover, the test does not reflect how the shaver blade functions within a shaver. A hand holding the hair provides significantly more counterforce than facial skin. Therefore, the test is—at best—of limited value. At a time when we had little information on how electric shavers work, Rav Feinstein’s tests were arguably necessary (although Rav Yosef Dov Soloveitchik and other top rabbanim did not require it). Today, the tests are undoubtedly unnecessary.

Next week, we present five other critiques and our respective responses.

Rabbi Jachter serves as the rav of Congregation Shaarei Orah, a rebbe at Torah Academy of Bergen County, and a get administrator with the Beth Din of Elizabeth. His 15 books are available on Amazon and Judaica House.