04.What's in a dishwasher detergent?
Alkaline salts are the main component of a typical dishwasher detergent. They help the cleaning process by reacting with fats on the dishes, but they're also what make this type of detergent dangerous if swallowed, as they have a similarly corrosive reaction in your mouth and throat. (See our article on the detergent dangers). They're water softeners too, which help the detergent work better by binding minerals in hard water.
Most of their cleaning performance is due to their very high pH level which dissolves dirt, but over time strips away glazes on crockery and wears away glassware, making it look cloudy and scratched over time. Some of the alkalis include sodium carbonate and sodium meta-silicate. The latter is particularly caustic and dangerous if swallowed – some detergents include up to 65%.
Other dishwasher detergent ingredients include:
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Surfactants Comprising only about 2% of the detergent, they work by lowering the surface tension of the water so it better wets the dishes to loosen dirt and keep it suspended in the water -- not go back on the cutlery.
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Chlorine or oxygen bleaches These help break down protein soils and aid in removing tea and coffee stains, but powders containing chlorine can shorten the life of your plastic kitchenware.
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Corrosion inhibitors Some detergents might include these to minimise corrosion of metal crockery and the dishwasher. They're usually aluminium salts.
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Enzymes The purpose of enzymes is to get good wash results at lower temperatures, which is better for your crockery. Enzymes break down protein and starch-based stains such as egg, pasta and cereal. Detergents containing enzymes work best at temperatures around 40°C -55°C above 55°C enzyme activity drops off sharply. You may see them listed as amylase or protease.
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Rinse aid These lower the surface tension of the rinse water so it easily runs off the dishes, taking any dirt with it and improving drying results. But for a rinse aid to work well it should be the last part of the detergent to dissolve, so that it becomes effective during the rinsing phase of program.
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Other additives Colorants and fragrances improve the look and smell. Thickening agents are used in liquid detergents to stop them from seeping through the dispenser. Fillers help the smooth flow of powder deterg