PEI (Porcelain Enamel Institute) is a wear-rating test, which simulates the effects of traffic on a floor surface. Based upon the type of traffic and the degree of dirt present, tiles begin to show signs of wear. The scale uses from 1 (lowest) to 5 (highest).
PEI 1: Floors in bathrooms or other areas with light traffic that are walked on essentially with soft-soled footwear or bare feet without possibility of presence of dirt.
PEI 2: Floors in living areas of homes with the exception of kitchens, entrances and other heavy traffic floors.
PEI 3: Floors in all residential interiors and light commercial applications like halls, kitchen, corridors, balconies and terraces.
PEI 4: Floors with considerable traffic for all residential interiors and most commercial areas like entrances, workrooms, Inns and exhibition and shopping malls and public areas.
PEI 5: All heavy-duty wear ability for residential and commercial areas.