Final answer:
For hand washing, it is recommended to wash hands under running water for 20 seconds using soap and warm water to effectively remove pathogens and help prevent the spread of colds and flu.
Step-by-step explanation:
When you need to flush an affected area with running water, as might be the case with exposure to chemicals or particulates, it is critical to do so for a sufficient length of time. If the situation is related to hand washing, washing your hands for 20 seconds with soap and warm water is recommended to help prevent colds and flu. This duration is generally considered effective for removing a significant number of pathogens from your hands, which can be present on various surfaces and contribute to the transmission of illnesses.