Shower waste biofilm. Coloured scanning electron micrograph (SEM) of debris from a shower trap. Skin cell embedded in a bacterial biofilm. Shower wastes and traps protect your shower from inconvenient drain blockages by retaining objects and stopping them from being swept down the drain. This debris often consist of organic and inorganic material, hair, skin cells, shampoo, soaps, as well as water. This debris is a ripe biofilm that may contain harmful microorganisms, including bacteria, viruses and parasites. Magnification: x2, 000 when printed at 10cm wide.