Dishwashers kill bacteria primarily through a combination of high water temperatures and detergent action. Here's how the process works:
High water temperatures: Dishwashers typically use hot water during the wash cycle, and the temperature can range from 120 to 160 degrees Fahrenheit (49 to 71 degrees Celsius). Such high temperatures are effective at killing many types of bacteria, viruses, and other microorganisms that may be present on dishes and utensils.
Detergent action: Dishwasher detergents contain various chemicals designed to break down and remove food particles, grease, and stubborn stains from dishes. These detergents also have sanitizing properties that help to eliminate bacteria and other germs on the surfaces of the dishes.
Rinse aid and drying: Many dishwashers use a rinse aid during the final rinse cycle. The rinse aid helps to prevent water spots and aids in drying the dishes more effectively. The drying process, along with the use of hot water and detergent, further reduces the number of remaining bacteria.
It's important to note that while dishwashers are effective at killing and removing bacteria, they might not completely sterilize dishes. Some heat-sensitive bacteria or spores may survive the dishwasher cycle. However, for most household purposes, dishwashers provide a high level of sanitation and cleanliness for everyday use. If you need to sanitize items more thoroughly (e.g., baby bottles, medical equipment, etc.), additional steps such as using sanitizing solutions or high-temperature dishwashing cycles may be necessary.