The Torah commands us to immerse metal  utensils that are purchased or otherwise acquired from a non-Jew in a mikva prior to their first use.  This mitzva is referred to as "Tevilat Keilim", the immersion of utensils.
The mitzva of tevilat keilim is often compared to the conversion of a Gentile to Judaism - just as a conversion to Judaism requires immersion in a mikva, so too a utensil which "converts" from Gentile to Jewish ownership requires immersion, as well. One is not required to immerse utensils which one borrows from a non-Jew. As we will see, the mitzva of tevilat keilim generally applies only to metal and glass utensils.
- 1 Basics
- 2 Procedure of Tevilah
- 3 Who Can Perform the Tevilah
- 4 Shabbat and Yom Tov
- 5 Beracha
- 6 Which Vessels require Tevilah?
- 7 Electric appliances
- 8 A Convert’s Obligation in Tevilat Kelim
- 9 If One Didn't Immerse a Utensil
- 10 Bodies of Water Fit for Immersing In
- 11 Links
- 12 Sources
- Utensils used for a meal that are bought from a non-Jew require Tevilah (immersion in a kosher mikveh).
- It is actually a matter of dispute amongst the authorities whether the mitzva of tevilat keilim has the status of a Torah commandment or a rabbinical one.Nevertheless, most halachic authorities treat tevilat keilim as a biblical mitzva for all intents and purposes.  All poskim agree that glass is only rabbinic.
- A non-kosher utensil should first be kashered prior to immersing it. 
Procedure of Tevilah
- One must immerse the entire vessel at one time and not half at a time. 
- One must make sure to remove all stickers, labels, and rust. 
- The utensil is immersed once, ensuring that it is completely covered by the water of the mikva. 
- One should hold the vessel loosely. 
- One should remove a knife from the case before immersion. 
- Ideally, a person should loosen his grasp of the kli for a second so that it leaves his grip for a moment. If a person is worried about it falling and breaking or getting lost, it is advisable to do the tevilat kelim over a basket. If that’s not possible such as with a large fragile kli, one should 1) first hold onto the kli with both hands, 2) remove one hand momentarily and then grasp it again, 3) remove the other hand and grasp it again.
Who Can Perform the Tevilah
- A child under Bar Mitzvah can only do Tevilah in the presence of an adult. In such a case he can even make the Bracha. 
Shabbat and Yom Tov
- According to Sephardim, it is permitted to do tevilat keilim on Shabbat or Yom Tov but initially one should give it to a non-Jew and then borrow it back and at that point it won't be obligated in tevilat keilim, but after Shabbat or Yom Tov one should do tevilat keilim on it without a bracha. According to Ashkenazim, one shouldn't do tevilat keilim on Shabbat or Yom Tov. Rather one should give it to a non-Jew and borrow it back. If it is a vessel that one could use to draw water one could use it to draw water from the mikveh and that is effective for tevilat keilim and doesn't appear as tevilat keilim.
- According to most poskim, Tevilat Kelim doesn't need kavana. Therefore, if a vessel fell into the mikveh it doesn't need to be toveled again.
- It is unclear whether or not one who converts to Judaism is required to immerse the utensils he already owns. 
- For one vessel the Bracha is Al Tevilat Kli and for multiple vessels the Bracha is Al Tevilat Kelim. After the fact, if one switched Kli for Kelim or the opposite one has fulfilled one’s obligation. Some say that there's a minhag to always recite the text Al Tevilat Kelim.
- If someone is going to be tovel a pot and a cover one should say Al Tevilat Kelim.
- One who is unsure whether or not one's utensils were purchased from a Jewish owned company should immerse them without reciting the accompanying blessing.
Which Vessels require Tevilah?
- While the immersion of metal utensils is required by Torah law, glass utensils must be immersed only by rabbinic enactment. Glass was incorporated into the mitzva of tevilat keilim because glass and metal share a common characteristic - they are both materials which can be melted and reconstructed when needed. 
- Metal, glass, crystal, pyrex, and duralux require Tevilah. However, plastic, nylon, earthenware, and vessels covered in earthenware do not require Tevilah. 
- Some say that porcelain requires Tevilah. Some say it does not need tevila.
- Plastic or wood cutting boards do not need Tevilah, but those who are strict and do Tevilah for it will be blessed.
- Earthenware dishes or fine china that have a glass glaze must have tevilat keilim without a bracha.
- Similarly, jars, bottles, or metal containers which are used only to store food and not used for food preparation or consumption should be immersed without a blessing. Utensils which are only used indirectly with food, such as bottle or can openers, and the like, do not require immersion. 
- Common custom is not to require the immersion of plastic utensils even though some authorities argue that the similarities between glass and plastic would require it. 
- Utensils which one is certain that they contain no glass or metal components need not be immersed. 
- Corelle dishes are halachically similar to glass dishes and should be immersed. According to most poskim they are immersed with a bracha. 
- One should immerse the kos of eliyahu used for the seder night without a beracha. 
- Regarding a seder plate if the food directly touches the seder plate it requires tevila and if not it doesn't.
- Tongs used to do tevilat kelim don't themselves need tevilat kelim.
- A mixer should have tevila without a bracha since it is usually used to mix foods which aren't ready to eat immediately.
- The mitzva of tevilat keilim only requires one to immerse those utensils which are intended to be used in food preparation or consumption. Most poskim hold that disposable utensils, such as aluminum pans, need not be immersed even if he decides to use it a number of times should do so. Others argue that disposable aluminum pans require Tevilat Keilim.
- This discussion is also relevant to food packages that are made out of glass or metal, such as a can of soda or wine. Even according to those who are strict generally about disposable utensils, there are only reasons to be lenient to leave the food in the packages.
- There is no leniency to use any utensil one time before tevilah.
Tevilat Kelim on Snapple Bottles
- One of the most famous practical issues of tevilat kelim is glass bottles like Snapple. This seems to be a big issue as it is a vessel that we drink from (so it is klei Seudah), so it should require tevilah. Some think that one use would be allowed even without tevilah, but that seems to be made up. So just because we are richer than we used to be and throw out (or recycle of course) this perfectly good glass bottle, should that exempt us from tevilas keilim?
- Rav Hershel Schachter (Ten Minute Halacha - Practical Tevilas Keilim Issues by Rabbi Aryeh Lebowitz, min. 8) says that in fact it is forbidden to drink from these bottles. Rather, when you open the bottle, you must pour the contents into another vessel before drinking. On the other hand, Rav Moshe (Igrot Moshe YD 2:40) writes that it is not an issue to drink from the Snapple bottle since the Jew who opens it is considered the one who created the vessel and then it would not require tevilah. Chacham Ben-Zion Abba Shaul (Or Litzion OC 1:24) agrees. Alternatively, R' Yechiel Yaakov Weinberg (Sridei Esh YD 2:29) suggests a different solution. He says when you buy the Snapple, just have in mind not to acquire the bottle and then you have no issue as you do not own the vessel and you can drink from the bottle. Rav Menashe Klein (Mishne Halachot 4:107) writes that it is permissible since one doesn’t have in mind to acquire the bottle because nobody wants to buy something prohibited. For a similar idea, see Yabia Omer 7:9:3.
Tevilat Kelim on Aluminum Pans
- The Gemara (Avoda Zara 75b) learns from the pesukim by the war with Midyan that when one buys utensils from a non-Jew one must immerse them in a mikveh before using them. Metal utensils are obligated in Tevilat Kelim. Though aluminum is scientifically a metal, there is a discussion in the poskim whether aluminum is considered a metal according to the Torah. In any event, our minhag is to be strict in this regard.
- Regarding aluminum tins, which are commonly only used once and then disposed of, there is a new point of discussion. Rav Moshe Feinstein (Igrot Moshe YD 3:23) proves from the rishonim that utensils which don’t last for an extended period of time, such as a vessel made from a pumpkin, don’t accept tumah. He assumes that since temporary vessels don’t qualify as a vessel for tumah, it must not also with regards to tevilat kelim. Seemingly, this applies to aluminum pans. Nonetheless, he adds, that vessels which could last a long time but are disposed of because they are cheap would certainly be obligated in tevilat kelim, even for a single use. Some, however, argue that even such vessels don’t qualify as a vessel. See above #Disposable_Utensils for general disposable utensils.
- Some hold that disposable grills don't need tevilat kelim. Others hold that they are obligated in tevilat kelim. 
- Modern-day electrical appliances present the mitzva of tevilat keilim with its biggest challenge. This is, of course, because water can damage electrical appliances or even cause harm to those who use the item following the immersion. There are differing approaches among the halachic authorities as to how one should to proceed with such items. Some authorities are of the opinion that anything which must be plugged into the wall in order to be used is halachically considered as if it were attached to the ground and anything which is attached to the ground is exempt from tevilat keilim.  Most authorities, however, reject this comparison and require even electrical items to be immersed just like all others. While some of these authorities require the entire item to be immersed along with all its electrical components, others say that only the actual components which come in direct contact with food need be immersed. 
Hot Water Urn
- A metal hot water urn does require tevilah with a Bracha. If its impossible to tovel it, one may give it to a non-Jew as a present on condition that he lend it back to you and it will not be obligated in Tevilat Kelim.
- According to many authorities a toaster requires Tevilah with a bracha. However, some argue that it doesn't require Tevilah.  Sephardim hold that that it requires but should be done without a bracha. 
- If the toaster will break by being dipped in the mikvah one should either bring it to an Jewish expert mechanic who will take it apart (to the point that no everyone would know how to fix it) and put it back together or to give it to a non-Jew and then borrow it from him. 
- A sandwich-maker needs to be Toveled. 
- A blender needs Tevilah with a bracha. 
- Some say that a microwave (glass) tray which does not touch food doesn't require Tevilah, and if it does touch food then it requires Tevilah. However, some say that one should dip it without a bracha in all cases.
A Convert’s Obligation in Tevilat Kelim
- There is a mitzvah to dip in a mikveh food utensils that one buys from a non-Jew called Tevilat Kelim. An interesting case arises when a non-Jew converts to Judaism. Are his pots, pans, and silverware considered as though they were acquired from a non-Jew, requiring Tevilat Kelim? Or, perhaps the mitzvah only applies when buying utensils and not when the utensils remain in the same domain.
- Rav Ovadia Yosef (Yabia Omer YD 7:8) entertains the possibility of exempting a convert from Tevilat Kelim because this situation isn’t similar to the original story of Bnei Yisrael acquiring utensils from Midyan in which the utensils changed domains and not that the owners have undergone a transformation. Rav Wosner in Shevet HaLevi (4:92:2) disagrees and says that even though the form of acquisition isn’t identical to the original story, the fundamental transfer from a secular domain to one of kedusha is applicable to a convert. Interestingly, the Sochachover Rebbe (cited by Yabia Omer) argued that the convert’s undergoing of conversion is sufficient to also convert his utensils and exempt them from any obligation of Tevilat Kelim. Rabbi Aryeh Leib Grossnass (Lev Aryeh Siman 25) recommends doing tevilat kelim without a bracha because of the dispute.
If One Didn't Immerse a Utensil
- A utensil may not be used, even once, before it is immersed in a mikva. 
- One, who for whatever reason, is unable to immerse a utensil which is urgently needed should give the item to a Gentile as a gift and then borrow it back from him. 
- If foods were placed upon or served with utensils which were not immersed in a mikva, it does not render the food non-kosher, though one should not eat off such utensils.  However, some are lenient to eat in a restaurant where the utensils are not dipped.
- Kosher food which was cooked in utensils which were not immersed in a mikva but is then served on dishes that were (or disposable dishes) may be eaten without hesitation.
- A guest in a home whose owner did not do tevilat kelim should not eat off the utensils but can pour the food onto plastic or paper utensils and eat the food.
If a Pot Got Mixed up with Others
- If one has utensils that a majority of them had tevilat kelim and one that didn't have tevilat kelim got mixed in and it isn't discernible which didn't have tevilah, one should do tevilat kelim on all of them. If it would be a major exertion of effort ask one's rabbi as there might be what to rely on. No bracha should be recited.
- If a utensil from a Jew is mixed into a majority of utensils from non-Jews there is an obligation to do tevilat kelim with a bracha. If one is only doing the tevilat kelim on one of the utensils at one time one wouldn't recite a bracha.
Bodies of Water Fit for Immersing In
- One shouldn't dip utensils in snow. If there's no other available options one may dip glass utensils in a mikveh.
- Tevilas Keilim Guidelines by the Star-K
- Tevilas Keilim: A Primer by the OU
- Hilchos Tevilas Keilim by Rav Hershel Schachter
- Taharat HaKelim (Kitzur, Full) by רב משה פרזיס
- Gold, silver, copper, iron, tin, and lead are all types of metal.
- Bamidbar 31:23; Rashi, Avodah Zara 75b
- Rashba (Yevamot 47b) and Issur veHetter HeAroch (Shaar 58 Ot 76) citing Yerushalmi Avoda Zara 5:16
- S”A Y.D. 120:8, Kitzur Shulchan Aruch 37:5
- Shulchan Aruch Yoreh Deah 120, Gemara Avoda Zara 75b
- Rabbenu Tam (Tosfot Yoma 78a), Rashba (Torat Habayit Ha'aroch 125b)
- Ramban on Parashat Bamidbar 31:23. See Yabia Omer Y.D. 2:9 for a list of both opinions.
- Aruch Hashulchan Y.D. 120:4, Sh”t Yechave Daat 4:44
- Pri Chadash 120:3
- Shulchan Aruch YD 121:2, Kitzur Shulchan Aruch 37:4
- Halichot Olam (vol 7, pg 253), Yalkut Yosef (Kitzur Shulchan Aruch Yoreh Deah 120:5)
- Yalkut Yosef YD 120:6, Kitzur Shulchan Aruch 37:10
- Kitzur Shulchan Aruch 37:10
- Halichot Olam (vol 7, pg 253), Yalkut Yosef (Kitzur Shulchan Aruch Yoreh Deah 120:5)
- Yalkut Yosef YD 120:6
- The Chelkat Binyamin 120:26 writes that there’s 4 opinions about whether holding onto the kelim poses as a chasisa:
- The Rama 120:2 and Levush 120:2 hold that as long as the hand was wet with mikveh water and wasn’t removed from the mikveh and then took hold of the kli it is an effective tevilah. However, if the hand was wet with regular tap water or mikveh water but was then removed from the mikveh and then took hold of the kli the tevilah is ineffective.
- The Gra holds that whether the hand was wet by mikveh water or other water the tevilah is effective.
- The Taz holes that if the hand was wet with mikveh water and didn’t leave the mikveh it is an effective tevilah even if she grabbed tightly. If the hand was wet with non-mikveh water or mikveh water but was removed from the mikveh and then it holds onto the kli tightly the tevilah is ineffective.
- The Mahari Bruna holds that even if the hand was wetted with mikveh water and didn’t leave the mikveh if it is holding tightly the tevilah is ineffective. The halacha follows the Rama but one should be strict for the Taz unless it is an extenuating circumstance.
- Shulchan Aruch Y.D. 120:14, Kitzur Shulchan Aruch 37:12, Yalkut Yosef YD 120:25, Sh”t Yabia Omer 2:9(8). The reason for this is established by the Trumat Hadeshen that either no intention is necessary for Tevilat Keilim since it isn't similar to purification from impurity and also it is possible to teach a child to have the correct intention.
- The gemara Beitzah 18a provides four reasons why it is forbidden to do tevilah of a tameh kli on Shabbat or Yom Tov. These include: a person might come to carry in a public domain, if it is clothing one might squeeze it out, one might delay all of one's tevilah until then, and it looks like fixing the kli. The Rif (Beitzah 10a) only records the reasons of squeezing and delaying and the Rambam (Yom Tov 4:17) only the reason of delaying. The Rosh (Beitzah 2:3) writes that according to the Rif it would emerge that it is permitted to perform tevilat keilim on Shabbat. However, the Rosh argues that we should follow the other reasons that gemara gave and so it would be forbidden to do tevilat keilim on Shabbat. Shulchan Aruch 323:7 rules like the Rif and Rambam that it is permitted but initially one should give it a non-Jew and then borrow it back from him, at which point there's no obligation of tevilat keilim.
- Mishna Brurah 323:36, Kitzur Shulchan Aruch 37:13
- The Rama 323:7 writes that one should do it in a way that appears that you're only drawing water from the mikveh. Kitzur Shulchan Aruch 37:13 writes that in general it is forbidden to do tevilat keilim on Shabbat or Yom Tov but rather should give it to a non-Jew and borrow it back.
- The Trumat Hadeshen 257 writes that a katan can have kavana for tevilat kelim and also tevilat kelim is chulin and doesn't need kavana, it is just a mitzvah unlike niddah (where the Rama 198:48 requires kavana initially). Rashba in teshuva 3:255 is clearly compares niddah and tevilat kelim, but in his conclusion he cites the Rambam who holds that even for Niddah kavana isn't necessary. Radvaz 1:34 thinks that the Rashba agrees with the Rambam. He explains that the general topic of mitzvot needing kavana isn’t relevant here since tevila and shechita are matirin and not mitzvot. Both the Shach YD 120:20 and Taz 198:17 write that we accept the Truamt Hadeshen and kavan isn't necessary for tevilat kelim. However, the Gra 120:38 sides with the Bach who thinks that initially you need kavana just like niddah (based on the comparison of the Rashba).
- Sh"t Shevet HaLevi 4:92, 6:245(2) holds that a convert is required to immerse his vessels. Sh”t Yabia Omer YD 8:7 writes that seemingly the convert wouldn’t be obligated to immerse the utensils and quotes the Sefer Devarim Achadim (Rav Eliyahu Kalskin Siman 196), Shem MeShmuel (Parshat Matot), Sh”t Nezer HaKodesh 17 who agree. Yabia Omer concludes that one should immerse metal vessels without a Bracha and one wouldn’t need to immerse glass vessels. See Tzitz Eliezer 8:19-20, 22:49.
- Shulchan Aruch Y.D. 120:3
- Pri Chadash 120:11, Bear Heitiv 120:4, Chelkat Binyamin 120:31, Yalkut Yosef YD 120:7
- Chelkat Binyamin 120:31 quoting Knesset Hagedola, Aruch Hashulchan, and Chachmat Adam. He writes that this is also the opinion of the Mordechai, Ritva, and Meiri a"z 75b.
- Chelkat Binyamin (Biurim 120:3 s.v. shenayim) has a doubt about being tovel a pot and a cover if that's considered one kli or multiple kelim since they function together. He concludes that there's no issue to just say tevilat kelim since many hold to say that even for one kli.
- Igrot Moshe Y.D. 3:21
- Pri Chadash 120:3, Aruch Hashulchan Y.D. 120:25
- Sh”t Yabia Omer 4:8, Hilchot Tevilat Kelim (Rabbi Moshe Fariz, 2:2-3)
- Hilchot Tevilat Kelim (Rabbi Moshe Fariz, 2:6) explains that even though some poskim held that it wasn’t obligated that was only because they were discussing porcelain which was ceramic not covered with glass, however, nowadays the common porcelain is covered with glass and must require Tevilah. Sh”t Yabia Omer 4:8 writes that porcelain doesn’t require tevilah.
- Rav Jachter quoting Rav Hershel Schachter because the glass coating is very thin.
- Hilchot Tevilat Kelim (Rabbi Moshe Fariz, 2:2-4)
- Yalkut Yosef Y.D. 120:2-3. See Igrot Moshe Y.D. 2:46 who in the context of kashrut and absorption of meat and milk writes that the glass glaze on china is insignificant and doesn't make it like glass.
- Shach Y.D. 120:11, Kitzur Shulchan Aruch 37:8-9, Shevet Halevi 6:245:4
- Melamed Lehoil 2:48
- Tzitz Eliezer 7:37, 8:26, Chelkat Yaakov 2:163, Yabia Omer Y.D. 4:8
- Kitzur Shulchan Aruch 37:3
- Star K and OU write that corelle dishes require tevilah with a bracha. Rabbi Binyamin Forst and Rabbi Doniel Neustadt agree. Rabbi Tzvi Haber of Los Angeleswrites that the obligation to immerse corelle is questionable and so one should dip it without a bracha.
- Rabbi Jachter quotes Rav Teitz and Rav Mordechai Willig as holding that corelle should have tevilah without a bracha. He also cites Ohelei Yeshurun p. 74 that Rav Moshe is quoted as holding that corelle strictly don't need tevilah but should have it without a bracha.
- Rav Osher Weiss
- Rav Willig (min 1) based on Sefer Tevilat Kelim p. 236
- Rav Willig (min 1)
- Rama Y.D. 120:5 writes that a shechita knife should have tevila without a bracha since it is generally used for shechita and prepare raw meat at which point the food is still not ready to be eaten. An article on OUkosher.org compares a mixer to this case.
- Rambam Keilim 7:5, Igrot Moshe Y.D. 3:23, Minchat Yitzchak 5:32. Or Hahalacha 120:27 writes that this is the majority of poskim.
- Or Letzion 1:24 writes that disposable containers that you decide to use more than once doesn't need tevilah since it is considered as though the Jew made it into a utensil.
- Chazon Ovadia (Shabbat v. 2 p. 56) writes that disposable aluminum pans require tevilat kelimim since they are considered a real kli even though they are disposable. Even if they don't have tumah they still require tevilat kelim since it doesn't depend on tumah as the Mahari Asad writes. Biography Pear Hadar p. 230 by Rav Eliyahu Abittan writes that Rav Ovadia regularly ruled this way. Rav Yitzchak Yosef (Motzei Shabbat Vayikra 5781 min 5) said that his father was lenient on disposable pans and even though he wrote they needed tevila he meant it is a stringency.
- Rav Ovadia Yosef in Yabia Omer YD 7:9:3 is strict generally regarding disposable utensils, nonetheless, he is lenient to use the packages made of metal or glass for storage. For example, liquor that comes in a glass bottle or a can of nuts which are made by non-Jews doesn't require tevilah immediately since one is only passively using the utensil (Maharil Diskin Kuntres Achron 136 s.v. vda). Furthermore, some say that one has intention not to buy the container but only the food inside (Mishna Halachot 4:107). Or Hahalacha 120:27 quotes this and agrees.
- Rama Y.D. 120:8, Yachava Daat 4:44, Avnei Darech 9:105
- Shulchan Aruch YD 120:1
- See Rav Yacov Kamenetsky in Emet LeYacov (YD 120:1). He concludes that you should dip without a beracha.
- Rav Hershel Schachter in a shiur on yutorah.org “Hilchos Tevilas Keilim”, Igrot Moshe YD 3:22
- An article on ou.org writes that aluminum pans are exempt according to Rav Moshe. Mishneh Halachot 7:111 fundamentally agrees with Rav Moshe but writes that aluminum pans are obligated since it could be reused many times.
- Chelkat Yacov YD 46, OC 152:2, Minchat Yitzchak 5:32
- Avnei Darech 9:105 writes that since the way people generally use the dispoable grills is to use it once and then throw it out because it is difficult to clean it is considered a utensil that can only be used once and is exempt from tevilat kelim. He is relying upon the leniency of Rav Moshe Feinstein in Igrot Moshe YD 3:23 regarding tin pans and expands upon it. He adds that if the way of the world changes and it is easy to clean and people do reuse them then it would require tevilah.
- Rav Yisrael Belksy in Shulchan Halevi 1:24:33:5 disposable grills made from strong metal need tevilah without a bracha. Also, in Avnei Darech he copies a letter he received in response from the author of Sh"t Michkarei Aretz who disagreed with him and holds that disposable grills which are sturdy and can be reused and just aren't for convenience need tevilah.
- Chelkat Yaakov 1:126
- Igrot Moshe Y.D. 1:57-58, Chelkat Yaakov 3:43
- Star-K Tevilas Kelim Guidelines, Kof-K article, Rabbi Mordechai Eliyahu
- Rabbi Mordechai Eliyahu explains that if its impossible to do tevilat kelim on a hot water urn or the like one may give it to a non-Jew on condition that they lend it back to you and then it will not require Tevilat Kelim.
- Mishneh Halachot 9:162, Bear Moshe 4:100, Teshuvot VeHanhagot 1:450, Sefer Tevilat Kelim 11:52 quoting Rav Shlomo Zalman and Rav Wosner, Bayit HaYehudi 39:6, Kof-K quoting Rav Yacov Kamenetsky that such is the minhag
- Sh"t Igrot Moshe YD 3:24
- http://halachayomit.co.il/QuestionDetails.aspx?ID=160 which is based on the opinions of Rav Ovadyah Yosef
- http://halachayomit.co.il/QuestionDetails.aspx?ID=160, http://www.moreshet.co.il/web/shut/shut2.asp?id=118646
- Rabbi B. Forst http://www.kashrut.com/articles/tevilas_keilim/ . din-online points out that it is possible to tovel a sandwich maker if you leave it to dry for 24 hours.
- Bayit HaYehudi 39:6, Tevilat Kelim 11:14, Mishneh Halachot 2:32
- Kof-K. Also, Ach Tov Vchesed YD p. 32 writes that if the microwave plate majority of the time doesn't touch the food directly it doesn't need tevilah.
- Rema Y.D. 120:8, Rambam Hilchot Maachalot Asurot 17:3. While the Chatam Sofer YD 114 writes that this prohibition is from the Torah, the Yeshuot Yaakov 120:1 holds this is only dirabanan.
- Rama Y.D. 120:16
- Yerushalmi Avoda Zara 5:15 and Tosafot and Rosh (Avoda Zara 75b), as well as Ramban, Rashba and Ran there, Rema Y.D. 120:16, Beiur Halacha 323
- Igrot Moshe 3:22, Shu"t Yechave Daat 4:44
- Darkei Teshuva 120:70, Shu"t Yechave Daat 4:44. This is based on Beit Yosef 120:8, where he writes that if somebody buys utensils for business purposes, and then lends them out to someone who will be using them for eating, the borrower need not dip them, and the Pri Chadash 120:22 and Aruch Hashulchan 120:43 agree with the Shulchan Aruch on that, even though other acharonim (including the Shach and Taz) disagree.
- Regarding the restaurant owner himself, Rav Shlomo kluger (tuv taam vidaat 3:23) says that a restaurant owner doesn't need to dip, unless most of his customers will be Jewish. Yechave Daat 4:44 is lenient on this as well, even if most of the customers are Jewish, even for metal utensils.
- Rama Y.D. 120:16, Igrot Moshe Y.D. 2:41
- Sefer Tevilat Kelim 3:10 citing many poskim who hold that a guest using the utensils is like someone borrowing them and using them without tevilah.
- The Teshurat Shay 2:104 writes that if a store bought utensils made by Jews and also utensils made by non-Jews and the majority are from the Jews then still the utensils need tevilat kelim. His reasoning is that it is a dvar sheyesh lo matirin since they can be put in the mikveh (similar to Shulchan Aruch YD 102:3). Even though the Maharshal Chullin 8:86 says that there's no dvar sheyesh lo matirin if an action is necessary that is qualified by the fact that nedarim are a dvar sheyesh lo matirin. Since nullifying a neder is a mitzvah it is a dvar sheyesh lo matirin even though it is an action. So too, to dip utensils in the mikveh is a mitzvah. Anyway, the Maharshal is against the Rashba Torat Habayit Haaruch 12b and Torat Habayit Hakatzar 8a, Shulchan Aruch 102:2, and Shach 102:8. Ruach Chaim YD 122:1 comes to the same conclusion. Halichot Olam v. 7 p. 276 and Darkei Teshuva 122:36 quote these poskim. Yabia Omer 2:9:3. (See Mayan Omer v. 4 p. 404 who quotes Rav Ovadia that it was only glass then one wouldn't need to actually dip it in a mikveh. In the footnote he discusses it potentially not being a dvar sheyesh lo matirin in light of the Tzlach Pesach 9b.) Nonetheless, it wouldn't be considered a dvar sheyesh lo matirin if it would cost a lot of money to do the tevilat kelim (Shulchan Aruch 102:3). Additionally, in general, Badei Hashulchan 102:33 quotes the Pri Chadash and Chayei Adam that if someone would require a great deal of effort to do it wouldn't be considered a dvar sheyesh lo matirin.
- Har Tzvi 93, Shevet Halevi 4:93. See however, Divrei Dovid 2:23 who argues that one should recite a bracha since we don't accept the Tzlach we hold that it is a dvar sheyesh lo matirin and as such it isn't batel and requires tevilah.
- Teshurat Shay 2:104 writes that if the majority of the utensils are from non-Jews there is an obligation to do tevilat kelim on all of the utensils. He adds that there’s no bracha for the one which was originally from a Jew since we don’t follow rov for brachot (Zachor Lavraham OC 3:60 s.v. eych). Also, since it is a dvar sheyesh lo matirin bitul is ineffective (see Magen Avraham 513:13 quoting the Maharshal). However, there is still a bracha for the ones that are from a non-Jew.
- Mordechai quotes the Rabbenu Shemaryahu who says that one may dip in a mikveh of snow even if it didn't melt. However, Rabbenu Eliezer argued. Bet Yosef YD 201:30 defended Rabbenu Shemaryahu but concludes that for biblical halachot one shouldn't dip a utensil in snow. Pitchei Teshuva YD 120:4 cites the Chachmat Adam who writes that for an extenuating circumstances we can rely on the Rabbenu Shemaryahu to dip utensils in snow that isn't melted. Hilchot Taharat Kelim 5:7 agrees if the snow is collected in a pit.