Styrofoam Cups and Aluminum Foil

Over the past several decades the kosher industry has grown considerably. Food companies recognizing the profitability of the kosher market have pursued kosher certification in an effort to increase marketability and sales of their products. What has been especially remarkable is that the pursuit of kosher certification has not stopped with food. It is not unusual to find nowadays a hechsher on non-food items. Are there really any viable kashrus concerns with something that is inedible? This article will focus on three popular household items, aluminum foil and pans, Styrofoam cups, and paper towels.

The potential kashrus concern with these kinds of non-food items is the use of use of processing aids or release agents during manufacturing. These raw materials are typically used to ensure that a product will not stick to a production line, molds, or pans, and are usually used to lubricate equipment or the product itself. It is standard practice in numerous industries to use release agents or processing aids, which at times could have a non-kosher component. It is certainly a worthy sheilah to address the issues involved since these products, which will later touch food directly, may possibly come into contact with a non-kosher processing aid or release agent. There is much written about this topic in halachic literature, and some poskim actually took a stringent approach when this question was first presented.

During the manufacture of aluminum foil, molten aluminum alloys undergo a series of rolling processes between top and bottom rollers. During this process, release agents or lubricants are applied to production lines that the foil comes into direct contact with. However, initially the potential kashrus concerns are somewhat abated, since during production the foil undergoes a process known as annealing, which exposes the foil to a heat exceeding 1,000 degrees Fahrenheit. This process would certainly burn any non-kosher residue the aluminum foil might have come into contact with, and also qualify as a kashering through the process of libun chamur. However, toward the end of the process the temperature does drop somewhat considerably. Although any foreign residue present on the foil’s surface would still certainly be burnt out, the process would no longer achieve kashering temperatures of libun chamur, and ta’am (taste) from lubricant at that stage would be absorbed by the foil. However, since the presence of release agents is always very minimal, any ta’am that the foil could possibly impart would always meet bitul proportions and become nullified in food. In halacha, this is known as a keili hassui lehishtamesh beshefah, which is a utensil that absorbed non-kosher taste in such minimal amounts, that the ta’am imparted by the utensil will always become botel in the food cooked. The Mechaber is lenient and allows one to use a keili hassui lehishtamesh beshefah without hesitation. However, the Taz disagrees and only permits the use of a keili hassui lehishtamesh beshefah if the issur and ta’am imparted is unpalatable. There is a debate amongst authorities if a utensil is permissible after a 24 hour period elapses, since once an eino ben yomo, the bliyos (taste absorbed by the utensil) would be no longer be palatable . This leniency would certainly apply to aluminum foil, which is never available for retail sale on the market until well after a 24 hour period has passed. Moreover, Rav Moshe Feinstein zt’l is quoted as being lenient with aluminum foil, with slightly different reasoning. According to Rav Moshe, since this particular type of kli (utensil) is never available for purchase until after a 24 hour period has elapsed, the gezeira mederabbanan should not apply altogether.

Aluminum pans are manufactured in a similar fashion to foil and the potential kashrus concerns are similar. However, there is one additional consideration with pans. During manufacturing, thick foil is stamped and formed into a pan shape and a very thin non-stick coating is applied. This thin coating is a possible point of concern as well. Therefore, some recommend washing the pans before use , although it is questionable whether this will effectively remove the coating from the pan and obviate this concern. Nevertheless, since the amount of any possible treifos present would be highly minimal, there is still basis to be lenient.

Although there is a possibility on some level that these questionable materials could contain non-kosher components, research appears to indicate that this issue is more likely to be just theoretical. Another very important piece of the puzzle is that very often a release agent or aid, even when containing a non-kosher component, is independently foul tasting and not fit for consumption. Although these materials will even come into direct contact with food, they are present in such minute amounts that they will not alter a product’s quality profile or taste. If the agent is foul tasting and independently inedible it should be permitted on the basis of being nifsal meachilah. Nevertheless, there is an opinion that if possible, these items should lechatchila be purchased with a proper hechsher.

There have been rumors in recent years that polystyrene cups, colloquially known as Styrofoam, contain a non-kosher component that could make one’s hot drink treif. This is inaccurate and is based on partially true assumptions. It is accurate that most likely, a non-kosher material is used during the processing of the cups. During the manufacture of Styrofoam cups, polystyrene “beads” are mixed with zinc stearate and filled into molds. The zinc stearate is used as a release agent that enables the cup to detach from the mold after the beads have been melted and fused together. A component of zinc stearate is stearic acid, which may be tallow based from a treif animal. However, there are several considerations that should address this concern. The first consideration is that zinc stearate is tasteless, which could render it permissible despite being present in a mixture. The Shach has a well known position that a non-kosher substance that is tasteless remains prohibited in a mixture, unless its presence meets bitul proportions and becomes nullified. However, there are numerous authorities that dissented with the Shach. According to those opinions, since zinc stearate will not impart any actual taste from a Styrofoam cup into a hot drink there should be no problem. Secondly, the amount of zinc stearate that could possibly migrate from the cup into one’s food is well below what is required for bitul. A Styrofoam cup certainly would have the status of a keili hassui lehishtamesh beshefah. Therefore, the only concern would be a question of violating the rabbinic prohibition of ein mevatlin issur lechatchila (intentionally nullifying an issur), which based on the discussion above about aluminum would not a problem according to many poskim after a 24 hour period elapses after manufacturing. Despite the claims of some that they witness thin oil slicks floating at the top of their coffee in Styrofoam cups, that is actually just natural oil from the coffee itself.

The potential concern with paper towels is different from aluminum foil or pans. The issue with the towels is the adhesive or glue that is applied to the roll, which allows the first few sheets to stick together and prevent the roll from unraveling. This adhesive contains numerous components and as a result many rip off the first three sheets before use on Pesach, lest any adhesive present on those sheets contain chometz or kitniyos. However, some take the position that this is not necessary since the adhesive or glue is a non-food item that is not at all fit for eating by any standard, and should be completely permissible. It is interesting to note that glue can also contain derivatives from treif animals, and discussion of this topic should not be limited to only Pesach. Those that are lenient on Pesach would also take a lenient position throughout the year, since glue is not fit to eat as a food. There are no concerns with the paper itself.

Like all other issues, consumers should consult their Rabbonim for direction.

OU Kosher Staff