Acknowledging risk migration in recycling

Maddalena Ripa

How can science and policy deal with the uncertainty of the potential risks the recycling poses to human health and the environment?

The main idea behind the Circular Economy is that materials are reused for long periods of time; much more than is already the case. In the current system, recycling undergoes a process of downcycling. This means that materials and products are designed to have one single life, so that when they are recycled, they lose valuable properties such as quality and functionality every time they are reused. The problem is that chemicals need to be added to recycled products to improve their quality each time they are reused. This process is polluting, and recycled materials often contain more additives than the original product. It is no surprise then that recycling reduces the quality of the materials, as it is difficult to manufacture the same product again and again.

With plans to recycle more as part of new Circular Economy initiatives, closing the loop on a global scale presents new uncertainties. An increase in recycled products including plastic, paper and cardboard, lubricants and other products can cause unpredictable health and safety problems. This is important when considering that the recycling of products contains toxic chemicals. If waste re-enters the economy as either new products made with recycled materials or as secondary raw materials to be traded, it may create a double exposure to toxic substances.

Take Brominated Flame Retardants (BFRs) as an example. These chemicals are commonly found in furniture and building materials, and are increasingly seen in electronics as metal components become replaced by plastic. BFRs are almost entirely banned in countries across the European Union, as they can lead to health problems such as lower mental, psychomotor and physical development. Nevertheless, they are still persistent on the market. BFRs appear in products imported from countries such as China, where e-waste is on the rise and recycling regulations and policies are less stringent. Plastics recovered from electronics contain PBDEs (Polybrominated diphenyl ethers), one of the most commonly used BFRs. PBDEs generally end up in recycled plastics because these toxic, bio-accumulative and persistent substances cannot be easily separated from plastic waste streams. In addition to direct migration of BFRs from waste materials, there is evidence that higher brominated flame retardants can undergo degradation and de-bromination during waste treatment. In some instances, this may lead to the formation of more toxic and bioavailable compounds. In effect, PBDE would be released into the environment and wildlife, endangering human health, two times during a product lifecycle.

Similar risk migration concerns have been raised for paper recycling. Several studies have demonstrated that paper, cardboard and waste paper potentially contain a significant number of chemicals, some of which have been classified as ‘critical’. This is because they are likely to remain in the solid matrix during paper recycling and end up in new products where their concentration may be even higher when compared to virgin fibre-based products (for example in case of phthalates and phenols). One of the most controversial examples refers to the detection of small quantities of BPS (bisphenol-S) in paper products. These are often made with recycled content such as napkins, flyers, and magazines. Bisphenol A and S are chemical compounds used as strengtheners in polycarbonate plastics, epoxy resins in water pipes, coating on the inside of food and beverage cans and in making thermal paper (used in sales receipts, for example). These compounds are toxic to human health, due to their hormone disrupting properties, and potentially to the environment. The amount of BPA released during recycling can vary widely, depending on the processes used, but recent studies suggest that BPS, like BPA, is transferred from thermal paper that has been recycled and accumulates in the recycled products.

The uncertainties created by the Circular Economy have to be acknowledged both by policy and by science. With regard to policy, the European Commission is issuing new regulations regarding the use and recycling of these toxic compounds. This approach can be seen as a precautionary approach to policy making.

But what is the response and responsibility of the scientific community? One possible answer to this challenge is uncertainty assessment, which Jeroen van der Sluijs is developing together with the Health and Environment Surveillance Committee of the Netherlands Health Council. The purpose of this work is to conduct a quality check in terms of uncertainty on potential side-effects of policy measures in order to alert the authorities to important links between recycling, the environment and human health. The role of science in this case is not only that of producing facts, but also that of communicating uncertainty.

From the MAGIC Nexus Project we will keep investigating how governance in the context of uncertainty leads to the emergence of new roles for science and for policy.


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