Triethanolamine is a pH adjuster that can also be found in makeup products such as mascara, blush and foundation. It alters the pH of a product to improve stability over time. Every formula has an optimum pH to make it work best. For example, a formula that’s more acidic works better for soap scum removal. Its opposite, a formula that’s 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 rust in a can.