Citric acid is a builder that can also be found in a wide array of household products including laundry detergents, shampoos and cleaners. Of course, citric acid is also found in citrus fruits, such as oranges, lemons and limes. We use it to make a product formula clean better by affecting the molecules in the formula so they work together better. Citric acid can also be used as a pH adjuster that alters the pH of a product to improve stability. Every formula has an optimum pH to make it work best. For example, a formula that is more acidic works better for soap scum removal. Its opposite, a formula that is more alkaline, might be more effective as a carpet cleaner. We use pH adjusters to make sure we achieve the best pH for a particular job. Also, the pH of a formula can affect how long it lasts within a container – for example limiting its tendency to corrode a tin, container or dispenser. We also sometimes use citric acid as a cleaning agent that removes hard water deposits, or as a chelator.