Explain why biological washing powders are able to remove food stains from clothes at lower washing temperatures than non-biological detergents, and state one limitation of using biological washing powders.

Biological washing powders contain enzymes such as proteases, lipases and amylases that hydrolyse the protein, fat and carbohydrate components of food stains. The enzymes break the large, insoluble stain molecules into small, soluble fragments that can be rinsed away. Because the enzymes act at relatively low temperatures, a lower washing temperature is sufficient and high temperatures are not required.

One limitation is that the enzymes can be denatured by high temperatures or extreme pH, so they may lose activity in very hot or very acidic/alkaline water, and some people may have allergic reactions to the enzymes.