Two-handle faucets are most often found in the bathroom, but you see them in some kitchens. Two-handle faucets use three types of mechanisms. The first two are the same as two of the mechanisms used in a single-handle faucet: cartridge and ceramic disc. The third type is a compression (or reverse-compression) mechanism. Compression faucets are the simplest type, using rubber washers that get compressed against one another to seal the valve. They do tend to wear out faster than other faucet types, but are also least expensive to repair.
When a person has a blockage in their sewage system they often try to fix it themselves by adding an acid or a base such as Drano in an attempt to dissolve or dislodge the problem. These chemicals can get into the plumbers eyes when the sewage is splashed during the repair. The plumbers skin during the repair does come into contact with the sewage water. The owner of the toilet might not report to the plumber they have already tried Drano a highly caustic base .