All Steri Sweep products are VOC compliant and we make a strong effort to ensure the use of only “green” products. The surface you need cleaned will determine what chemical will be used. How dirty your surface is will determine how much chemical will be used. Our power washers allow for variable pressures to keep minimal pressure on a particular surface. Cleaning vinyl siding with our soft washing technique uses a mixture of eco-friendly chemicals and very low pressure. For some concrete cleaning jobs, we do not need any chemicals. Just good ole fashioned water pressure and a flat surface cleaner designed specifically for concrete cleaning. The deck cleaning chemicals we use depend on the type of deck and staining application that is currently being used.