Within the retro computing community there exists a lot of controversy about so-called ‘retrobrighting’, which involves methods that seeks to reverse the yellowing that many plastics suffer over time. While some are all in on this practice that restores yellow plastics to their previous white luster, others actively warn against it after bad experiences, such as [Tech Tangents] in a recent video.

After a decade of trying out various retrobrighting methods, he found for example that a Sega Dreamcast shell which he treated with hydrogen peroxide ten years ago actually yellowed faster than the untreated plastic right beside it. Similarly, the use of ozone as another way to achieve the oxidation of the brominated flame retardants that are said to underlie the yellowing was also attempted, with highly dubious results.

While streaking after retrobrighting with hydrogen peroxide can be attributed to an uneven application of the compound, there are many reports of the treatment damaging the plastics and making it brittle. Considering the uneven yellowing of e.g. Super Nintendo consoles, the cause of the yellowing is also not just photo-oxidation caused by UV exposure, but seems to be related to heat exposure and the exact amount of flame retardants mixed in with the plastic, as well as potentially general degradation of the plastic’s polymers.

Pending more research on the topic, the use of retrobrighting should perhaps not be banished completely. But considering the damage that we may be doing to potentially historical artifacts, it would behoove us to at least take a step or two back and consider the urgency of retrobrighting today instead of in the future with a better understanding of the implications.