11 plumbing and environmental protection supplies, namely parts for plumbing fixtures in the nature of fixture support brackets for wall-hung (off-the floor) toilets, lavatories, urinals, sinks and drinking fountains; backwater valves to prevent sewage backflow into buildings, and plumbing sink traps; and grease and oil interceptor/separator and waste receptor to intercept, store and enable the removal of such materials from the system