These sterile alcohol pads contain 70 percent isopropyl alcohol to clean skin and kill germs, making it ready for an injection In addition to skin, the pads can be used to sanitize hands and surfaces These 1-1/5 inch by 2-3/5 inch pads are portable for convenience McKesson alcohol prep pads are made of non-woven, non-linting material to keep cleaned areas sterile The alcohol evaporates quickly, without leaving behind any residue They come in a convenient pack of 10 individual single-use sterile pads .