- Peninei Halakha
Clothes worn by babies who regularly soil their outfits are not included in the prohibition. Likewise, one may wash sheets and blankets of young children who wet themselves at night. In addition, many people are lenient, in a time of need, with regard to washing older children’s clothes, because they soil their clothes as well, and there is no element of joy in doing laundry for them (Rema 551:14). Ashkenazim may rely on this leniency le-khatĥila until Shabbat Ĥazon (mb 551:82, based on Ĥayei Adam). Afterward, one may be lenient and wash older children’s clothing only if there is a great need, such as when all of their clothes are soiled to the point where it would be unbecoming for children to wear them.
When one is washing children’s clothes in a washing machine, one may not add adults’ clothing to the load. In addition, it is preferable, if possible, to dry even children’s clothing discreetly, inside one’s home, so as not to appear as if he is not mourning.
In a hospital, one may change patients’ bedding and wash their clothes as one would do throughout the year, because the purpose of laundering these items is to maintain cleanliness and prevent infections, not for pleasure or added comfort. Guest houses and hotels may change their bed sheets for incoming guests, because people today find it disgusting to sleep on previously used bedding (Tzitz Eliezer 13:61). Ideally, a hotel guest should step on the new sheets a little before using them, so that they will no longer be considered freshly laundered. He should then ask the attendants not to change his bedding until after Tisha Be-Av.
 Rema 551:14 states that the prevailing custom is not to refrain from washing children’s clothing. We are lenient in this regard until the age of ĥinukh, i.e., six, and in a time of need we are even more lenient. Hilkhot Ĥag Be-ĥag 4:16 states in the name of R. Elyashiv that it is customary to regard eight-year-olds as small children. It would seem that older children who get themselves very dirty should be viewed as small children for this purpose.
 A Jew may not do laundry for a non-Jew during the week in which Tisha Be-Av falls. Even Ashkenazim are stringent in this regard only during the week of Tisha Be-Av (mb 551:43). This is prohibited because of mar’it ayin ("appearance" of transgression), meaning that people will think that he is washing a Jew’s clothes. If, however, it is clear that the clothes belong to a non-Jew, he may wash them. A Jewish cleaner who has nothing to eat may wash clothes for non-Jews during this period (mb 551:42). One who runs a laundry service for a living may be lenient and operate it until Shabbat Ĥazon, even if he is Ashkenazic. The reason for this is that Sephardim are permitted to wash clothes until then, and Ashkenazim also permit laundering in certain cases, such as for a person who owns just one garment or in honor of Shabbat. (See Hilkhot Ĥag Be-ĥag 4:20, which permits such a person to work even during the week in which Tisha Be-Av falls, if he is liable to lose his job if he does not work. This requires further examination. See also ibid. 4:28.)