Light, oils and cigarette smoke can all discolour plastic over time. Food stains, particularly tomato sauce, inside storage containers can leave obvious discolouration, too. Discoloured and stained plastic looks shabby and can make a room appear dirty even though it is clean. A little elbow grease and common cleansers can make the plastic look nearly new again. Cleaning the discoloured plastic will improve the look of the item and the room.
Dampen the sponge and sprinkle the abrasive powder liberally on it. Scrub the plastic thoroughly to remove the dirt and surface staining and discolouration. Rinse thoroughly.
Fill a bucket or the sink with one part oxygenated bleach and one part water. Regular household bleach may be used, but it can weaken the plastic.
Soak the plastic in the bleach solution for 30 minutes to one hour. Soak thick plastic items for up to two hours.
Remove the plastic after it has returned to the desired colour or the specified time has elapsed. Rinse thoroughly under running water.
Wash in warm water with washing-up liquid to remove all vestiges of cleaners and skin oils. Dry before using.
Gently sanding thick plastic with super fine sandpaper can remove the discoloured layer, but may make the plastic more prone to absorbing stains.
Avoid using abrasive cleaners on disposable food containers. Replace them instead.