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The black spatula was recently identified as an unexpected source of danger. A slew of coverage followed a research paper suggesting that toxic flame retardants in recycled black plastic could be leaching into food at hazardous levels. Your cool black kitchenware could be slowly poisoning you, one newspaper warned and a reasonable reader may have shared the Atlantic’s conclusion that the only safe course of action was to eliminate this ubiquitous and previously understated item. The peer-reviewed paper turned out to have miscalculated the dosage by a factor of 10, but the research lifted a lid on the normally hidden, and apparently murky, world of plastic recycling. So should we re-admit the black spatula into the cutlery drawer or is there genuine cause for concern?
What’s the issue with black plastic?
Recycled plastic, melded together from different coloured items, tends to come out an unappealing sludge colour. So to make products look sleeker and more uniform, manufacturers have commonly added a dye, carbon black, to recycled products. The problem is that when these products come to be recycled, the carbon black pigment makes them effectively invisible to the optical sensors used to sort different plastics apart in recycling facilities. Manufacturers are now starting to use alternative black pigments that don’t cause this problem, but it appears that the issue has created a demand for black plastic that has been made by electronic waste, which comes through a different recycling stream. The casings of products like computers, TVs and coffee machines are typically treated with flame retardants to prevent electrical fires. This includes chemicals that have been shown to be toxic to humans at high levels of exposure and which are now banned in many countries. However, legacy plastics containing some of these chemicals appear to be still making their way through the recycling chain.
What did the original paper find?
The study, published in October in the peer-reviewed journal Chemosphere, looked at 203 black plastic household products sold in the US including kitchen utensils, takeaway containers and toys. The researchers assessed the levels of a flame-retardant chemical called decabromodiphenyl ether (BDE-209) that cannot easily break down in the environment, has been linked to potential human health risks and was phased out in the US more than a decade ago. But the study concluded that some kitchen utensils would result in a likely dose of 34,700 ng per day of BDE-209, which the scientists warned approaches the safe exposure limit advised by the US Environmental Health Protection Agency (EPA).
What did it get wrong?
Embarrassingly, the scientists had miscalculated the EPA’s reference dose by a factor of 10. This brought the estimated BDE-209 exposure from black spoons and spatulas down to less than a tenth of the EPA’s recommended limit. The authors said the error did not alter their overall conclusion that “recycling, without the necessary transparency and restrictions to ensure safety, is resulting in unexpected exposure to toxic flame retardants in household items”.
Nevertheless, it may change the degree of concern for the average reader. “I think it does change the flavour of the whole thing somewhat when you’re off by a factor of 10 in comparing something to the reference value,” Joseph Schwarcz, director of McGill University’s Office for Science and Society and the academic who first highlighted the error, told Canada’s National Post. “All of this merits attention, but you have to do it properly, and you have to make sure your numbers are correct before you scare the pants off people.”
So can I relax?
Although the paper overstated the risk, the story highlighted genuine tradeoffs that can exist between sustainability and product safety.
“Once you start understanding all these material flows and where they’re going it’s really complex,” said Mark Miodownik, professor of materials and society at University College London. “Recyclable content is good. But if it’s legacy plastics, they often have these quite horrible things in them. Food contact recycling is one of the really big problems of the packaging world.”
Should I throw away my utensils just to be safe?
There is also an environmental downside of disposing of plastics, especially those that are unsuited to being recycled. “If you decide to get rid of all the plastics in your house, the impact of disposing of stuff that still has a use could be quite significant,” said Adam Herriott, of the environmental campaign group, Wrap.
There are ways to ensure that plastics are used more safely: microwaving plastics that aren’t specifically designed to be microwaved could potentially leach chemicals into food, for instance. “It’s better to use what you’ve got until it no longer has a use then replace it,” Herriott added. “Don’t just go out and replace all your Tupperware and black spatulas.”
Are there other reasons to worry about plastic products?
The black spatula finding emerged against a backdrop of growing anxiety about the health and environmental impacts of plastic – and possibly provided a convenient, readily replaceable item that allowed people to act on these simmering concerns. However, experts say that the challenges of managing the risks around plastic use and reuse are far more complex.
“I wouldn’t put black spatulas at the top of my list of concerns,” said Miodownik.
More pressing, he said, is the addition of PFAs –“forever chemicals” – that are increasingly added to plastic food packaging, clothing and cosmetics and which are making their way into the human body. “The number of products they’re in is going up and up and with limited understanding of human health implications,” he said. “But they are in our bodies, increasingly so, and it doesn’t seem like a very good thing to do to our bodies and the environment.”
Similarly, microplastics are flowing into water systems and beyond. Even if microplastics themselves are inert in the body, they can serve as vectors for other chemicals with known health effects. Microplastics make their way into water supplies, partly due to people washing synthetic clothes, meaning it is difficult to limit exposure.
“It’s the stuff you can’t see that we should try to get a handle on – not the spatulas,” said Miodownik. “The PFAs, the microplastics. We need to scale back this technology because it’s getting everywhere.”
