As most everybody knows, the chemicals in most household drain cleaners are quite harsh, and can do a job on your skin. They need to be harsh, of course, to break up all that gunk that's blocking your drain. Before you start your controlled chemical spill, read the instructions on the bottle. You will see that you will need to wear both gloves and eye protection. To be on the safe side, use safety work gloves made from nitrile or neoprene, such as can be found in the cleaning section of your supermarket or do-it-yourself-store.