"My plant has noticed that our chillers are turning dark. We are cleaning the entire kill floor with a chlorinated detergent that is working well every place else. What are we doing wrong?"

Are the chillers aluminum? Using strong caustic, bleach and even acid solutions on aluminum chillers will actually damage the metal. Before using strong detergents on any equipment it is important to determine what kind(s) of metal might be contacted.

"Soft" metals (like aluminum) and ferrous metals (like plain steel) may be adversely affected by caustic, bleach and some acid. Do not assume that every piece of equipment in a plant is stainless – ask questions and, if in doubt, test a small area before applying aggressive detergents.