Excise duty adjustments: revised ad valorem and per unit duty treatment for polystyrene, PVC, plastic floor coverings and PU foam waste. Amendments revise central excise notifications to increase ad valorem duties for polystyrene and specified plastic floor coverings, prescribe an updated effective duty description for PVC paste grade, and set revised duty treatment and per unit rates and clearance limits for flexible polyurethane foam and its waste, parings and scrap by substituting and inserting entries in the tables of prior notifications.