Washing underwear and outerwear together can lead to health problems if proper precautions are not taken.
Firstly, if the outerwear is contaminated with bacteria or viruses, they can transfer onto the underwear and cause infection or illness. This is especially true for items such as gym clothes, which may have come into contact with sweat and bacteria.
Secondly, if the outerwear is heavily soiled, the detergent and agitation from the washing machine may not be sufficient to remove all the dirt and bacteria, which can then transfer to the underwear.
Lastly, some outerwear, such as clothing with metal zippers or buttons, can cause snags or tears on the underwear, potentially leading to rips or holes.
To avoid these potential health problems, it is recommended to wash underwear and outerwear separately, and to use a mild detergent and a gentle cycle when washing underwear. It is also important to wash heavily soiled outerwear separately, and to check pockets, zippers, and buttons before washing to avoid any damage to the underwear.