Whitening yellowed plastic requires a cleaning agent such as bleach. Another method requires using sandpaper to sand off the top layer of the plastic. It is important to wear proper hand protection when removing stains from plastic. If a chemical method is used for cleaning, proper eye protection is also important.
Yellowing plastic occurs because of a chemical reaction when the plastic is exposed to oils or light. Before selecting a cleaning method, it is important to determine the location and scale of the cleaning project because certain methods, such as using bleach, are better suited in well-ventilated areas. When using bleach, users combine one part bleach with one part water and soak the yellowed plastic until it reaches the desired level of whiteness. The bleach residue must then be washed off with a mild detergent, and the plastic needs to air dry. When using sandpaper, users wipe down the plastic surface and sand off the top layer to reveal the white surface underneath. Afterward, any remaining dust must be wiped down. Superfine sand is recommended in order to minimize the potential damage to the plastic surface. Cleaning a surface with a commercial cleanser such as Comet may take more time than other methods because it is a milder cleaning agent. After soaking the plastic in water, the next step is to apply Comet to a scrubbing sponge to use to scrub the stains out. The final step is to wash off the surface of the plastic.