Plastic In the UK, 500 million pots and trays are now produced each year and we nearly all have an assortment of plastic containers in our garden sheds. If we reuse them it will keep them out of landfill, and if they break they can in most cases be recyled. Our plastic pots are made from either high-density polyethylene (HDPE) the same as bottles for milk and washing-up liquids, polypropylene (PE) the same as margarine tubs and microwaveable meal trays or recycled high impact polystyrene (PS). The polypropylene pots and trays are sturdy, reusable many times and are heavier because they contain more plastic. The recycled Polystyrene pots and trays are lighter in weight and contain less plastic. They have thinner walls and can be reused if handled carefully.