266. Obstructions on the Hands

40:11 One must check his hands before washing in order to ensure that they are clean and free from anything that would obstruct the water. (An obstruction is called a “chatzitzah” in Hebrew.) If one has long fingernails, they must also be cleaned. (Mishnah Brurah 161:3 say that this only refers to dirt on the nails beyond the length of the fingers, not to dirt between the nail and the finger.) Rings should also be removed. (This refers specifically to women, who typically remove rings to knead dough – MB 161:19.)

40:12 If one’s hands are dyed, if it’s just color without substance, it is not considered an obstruction. If there is any substance to it whatsoever, it obstructs. A craftsman or worker – for example, a painter who gets paint on his hands, a butcher whose hands are covered with blood, or a scribe whose fingers get dirty from ink - in all such cases because these stains are always there and the practitioners of these trades are used to them, they are not considered obstructions unless they cover the greater portion of the hand. (Most authorities say the greater portion of the fingers – Shaar HaTziyon 161:2.) If one has a bandage on a wound on his hand and it would cause pain to remove it, it does not obstruct. The laws of obstructions are discussed in greater detail in chapter 161, regarding a woman attending the mikvah; all of those details also apply to the ritual washing of the hands.