Color Is The Enemy

Part of the appeal of plastic, when it first emerged in mainstream society, was the fact that it was colorful. It was not one thing—it could be many things. It was used in toys. It shaped our relationship with music. And vibrancy is still a major factor in its appeal, as highlighted by the fact that the Rabbit R1 came in a hue of orange so bright that reviewers have struggled to properly capture it on camera.

But a new study published in the academic journal Environmental Pollution suggests that maybe the colorful nature of plastics has gone a bit too far. In “Influence of colourants on environmental degradation of plastic litter,” researchers at the University of Leicester and University of Cape Town highlight the findings of a study involving bottle tops made of polypropylene, one of the most common plastics around—and as any Tedium reader who spotted our Sunday issue knows, one of the variants invented by the Phillips Petroleum Company in the 1950s.

The researchers left six colors of plastic bottle caps—red, green, blue, white, black, and silver—in the sun on a Leicester roof for three years. The researchers then found that the more colorful variants dramatically decayed in the sun, while the ones without any coloring looked largely normal. Another element of the research involved grabbing old plastic at South African beaches and analyzing it based on manufacturing dates that go back as far as 45 years. There, too, the darker plastics held up more successfully than the brighter ones.

Well, when you put it that way … (Environmental Pollution)

As the abstract of the research argues:

It appears that carbon and titanium dioxide colorants protect the HDPE polymer from photolytic degradation. While anthraquinone, phthalocyanine and diketopyrrolopyrrole pigments were found to enable UV light to degrade the polymer leading to brittle plastics, promoting the formation of microplastics, it is likely that other pigments that do not strongly absorb in the UV will result in similar degradation.

This appears to be an important finding that could reshape our relationship with plastics long-term. Dr. Sarah Key, the lead researcher of the project, noted that the dramatically different environmental factors behind the two halves of the study is particularly telling.

“It’s amazing that samples left to weather on a rooftop in Leicester and those collected on a windswept beach at the southern tip of the African continent show similar results,” Key told The Guardian. “What the experiments showed is that even in a relatively cool and cloudy environment for only three years, huge differences can be seen in the formation of microplastics.”

Now, microplastics are kind of a big problem these days, and knowing that the colorings we use to create plastics can contribute to them could cause issues down the line might create a strong case to limit our use of colorful plastics, at least in more disposable settings.

Of course, this is complicated, and one big reason for that is the fact that the cultural value of color is really strong. Entire industries are built around color, and removing one of the most valuable tools we have for implementing it in our culture would be hugely problematic and might see pushback from marketers, toy-makers, food producers, and others. Imagine if the only Lego colors for sale were white, black, and gray.

But on the other hand, it’s worth considering the many places microplastics are appearing. Among them: Table salt, prehistoric rocks, modern rocks, clouds, and the male anatomy. It’s almost like we have to decide: Do we like the color red, or properly functional male fertility?

It is yet another sign that we are at the mercy of bad decisions we made decades ago, that we’re now stuck with. But does reversing this trend mean that we have to be stuck with a duller, less colorful world in the process?