Bleach yellow plastic

The 'Retr0bright' Project

Many things are made of ABS plastic with flame retardant that causes the plastic to turn yellow or worse. The folks at Retr0bright have developed a public domain DIY formula to bring the brightness back to precious plastics.

"...the possible causes of the yellowing ...eventually we arrived at the theory that it was the Bromine in the flame retardant that was the cause. We also knew that Ultra Violet light was another major factor. Having identified the culprit, the next stage was to try to develop and perfect a means of treating the plastic and reversing the yellowing quicker, without causing damage to the plastic. Being a former industrial chemist helped me tremendously, in understanding what was going on at the molecular level and to develop a treatment process to reverse the effect."

The problem was finally cracked with a mixture of hydrogen peroxide, a small amount of an “Oxy” laundry booster as a catalyst and sunshine or a UV lamp; glycerine can also be added to make the mixture sticky.