May one wash hands for bread/morning with a Band-Aid?
One who has an injury on his hand and a bandage that is covering it, may wash his hands without removing the bandage if he is unable to remove it due to the pain of the injury. [This applies even if the bandage is covering majority of his hand.] It suffices for him to wash the remainder of the hand that is not covered by the bandage. (If, however, he is able to remove it [without it causing pain] then he must do so prior to washing, as otherwise it is considered a Chatzitza.) Thus, if one has a bandage covering a minor discomfort of the skin and not an actual injury, and is able to remove it whenever he desires [without any real pain] then he must do so prior to washing.
How to wash with a bandage: In the event that one is allowed to wash with a bandage on his hand, care must be taken that water does not touch the bandage. He is to thus wash until the area of the bandage, and make sure that water does not fall onto the bandage. Being however that it is difficult to beware of this, therefore, he is to pour an entire Revius [86 milliliters] simultaneously on the entire hand, and thus avoid the need to prevent the water from touching the bandage. [Nevertheless, according to Admur in the Siddur, one is to beware that water does not touch the bandage even when pouring a Revius of water on the hand. If, however, it is not possible to do so, the washing is valid if he pours a Revius at a time.]
What is the law if the band-aid/bandage became removed during the meal?
If the bandage contains two coverings, must one remove the outer covering?
 Admur 161/2; 162/15; Michaber 162/10; Tur; Rosh Chulin 8/18; Ketzos Hashulchan 33/3
 Admur ibid; Michaber and Rosh ibid; However, see Michaber 161/1 who states it must be removed due to Chatzitza; see next footnote for Admur’s distinction and that of other Poskim
 Admur ibid; Rosh, brought in Bach and M”A 162/18; Taz 161/2; This answers the contradiction in the opinion of the Michaber ibid
The reason: This washing is not considered “Netila Lechatzain/half washing” being that he is unable to wash the “second part of the hand” [i.e. the area under the bandage] and is thus similar to one who lost a finger in which case he is to wash the remainder of the hand. [Admur 162/15; Tur and Beis Yosef in name of Rosh; P”M 161 M”Z 2 in explanation of Bach in M”A 162/18] It is thus not considered a Chatzitza at all at this time, although on the other hand is not nullified to the hand and hence requires one to be careful that water not touch the bandage, as will be explained. [Admur ibid]
Other opinions/reasons: Some Poskim rule the reason it is not a Chatzitza is because one is not Makpid on it and if one were Makpid on it then it would be a Chatzitza. [M”A 162/18 in name of Lechem Chamudos in answer to contradiction in Michaber ibid; Admur explicitly negates this explanation in the continuation of 162/15] Other Poskim rule it is not a Chatzitza since one will not remove it during the meal due to the pain involved, and hence the impure area will not touch the bread. If however he has a mere skin discomfort that is close to painless, and there is thus worry that he might remove the bandage during the meal, then he must remove it, as it is a Chatzitza. [M”A ibid in name of Bach, and that so is main opinion; Taz 161/2; Olas Tamid 161/3; Elya Raba 161/4; Mamar Mordechai 161/4; Chesed Lealafim 161/1; M”B 161/5; Kaf Hachaim 161/6; See P”M ibid and Rav Akiva Eiger 162/18]
 P”M 161 M”Z 2; Kaf Hachaim 161/6; Nishmas Avraham 4/161
 Admur 162/15; Taz 161/2
 Admur 161/2; M”A 162/18 in name of Bach; Taz 161/2; Olas Tamid 161/3; Elya Raba 161/4; Mamar Mordechai 161/4; Chesed Lealafim 161/1; M”B 161/5 and 162/68; Kaf Hachaim 161/6
 Admur 162/15; Michaber ibid; Rosh ibid
 The reason: As if the water drops onto the bandage then if it drops back onto the hand it impurifies the hand. A second washing does not help purify this water that is on the bandage. Although the bandage is not considered a Chatzitza at all being that he is unable to remove it now, nevertheless it is not nullified to the hand to the point that its water can be purified with a second washing, as one does plan to eventually remove it. If however in truth he does not care to ever remove it, then it is nullified to the hand and does not require one to beware that water does not touch it. [Admur ibid; Michaber ibid]
 Admur ibid; Rashal, brought in Taz 162/8; Michaber ibid gives this suggestion as well, although does not advise to follow specifically this suggestion
The reason: As a Revius does not contract impurity and hence avoids this entire issue. [Admur ibid]
 See Seder Netilas Yadayim 2 that one who desires to fulfill his obligation according to all is to suspect that even a Revius contracts impurity. Accordingly, it would not help to pour a Revius over the entire hand and allow the water to touch the bandage, and hence even when pouring a Revius one must beware that the water does not touch the bandage. [Ketzos Hashulchan 33 footnote 12]
 Ketzos Hashulchan ibid; See Piskeiy Teshuvos 162 footnote 87
The reason: As in such a case one may rely on the ruling of the Admur in his Shulchan Aruch ibid that a Revius does not contract impurity. Furthermore, even from the Siddur it is evident that one may rely on this opinion in a time of need, as Admur in the Siddur rules regarding the morning washing that if one has only a small amount of water he is to pour a Revius over the hands simultaneously. [Ketzos Hashulchan ibid]
 Halachos Ketanos 2/132, brought in Hagahos Hatur;
 The reason: As since one washed his hands according to Halacha, the entire hand is pure and there is no impurity that resides under the bandage. [ibid]
 Mahariy Malko 145, brought in Birkeiy Yosef 161/4; Shaareiy Teshuvah 161/2; Zechor Leavraham 161/50; Ben Ish Chaiy Shemini 14; M”B 162/71; Kaf Hachaim 161/7
 The reason: As one may not wash his hands in halves, and the impurity was simply covered over by the bandage, and now that it was removed, the impurity of that area must also be washed off. [ibid]
Is a blessings recited? See Piskeiy Teshuvos 162 footnote 92
 As reason offered by Admur for why the bandage is valid
 Shaar Hatziyon 162/58
Other opinions: Some Poskim rule that even in such a case one must rewash the hand prior to replacing the badange. [Chazon Ish 24/25]
 See Shaar Hatziyon 162/27