Lots of things. Instant Powder Kegs is a powder. In many areas, OSHA requires that coil cleaning liquids be specially stored to avoid leaks. Further, many times coil cleaner plastic containers leak, and get the corrosive liquid over vans, floors, and other areas. This can get messy, and difficult to clean up. Leaky containers can also corrode tools, metals, and other products that may be nearby. As well, have you ever carried a gallon jug of coil cleaner up a ladder while holding on with the other hand? These are some of the reasons users prefer Instant Powder Kegs.