Solutions for recycling plastic bottle caps

There tends to be an overall lack of clarity on the guidance around the recycling of plastic bottle caps. Governments and manufacturers around the world are looking at providing further clarity and simplicity to the process such as legislation on mandatory tethered caps and reducing plastic packaging. 

 What should you do with plastic bottle caps?As the devastating environmental effects of single-use plastics become increasingly more apparent, alongside a growing list of government policies to reduce their ecological impact, it is becoming clearer that consumers must also play a part in changing our throwaway culture.

With an estimated 14 billion single-use plastic bottles used each year by UK consumers, the challenge is sizeable. The problem is compounded when taking into account the estimated 14 million plastic bottles that are not recycled on a daily basis.

However, with the upcoming deposit return scheme for drinks bottles and cans by 2025 and the implementation of a plastics tax in 2022 for packaging containing under 30 per cent recycled content, disposable beverage containers are under scrutiny like never before.

Yet, one aspect of the issues posed by such containers remains relatively unaddressed – plastic bottle caps. They have caused confusion among consumers for as long as plastic bottles have been recyclable, and often end up being thrown in the general waste bin or dropped as litter.

Globally, more than 20 million bottle caps have been discovered during beach cleaning campaigns over the last 30 years. With bottle caps cited as being within the top five most dangerous pollutants for marine life, their pollution deserves greater attention.

As bottle caps are frequently ingested by many mammals, birds and sea life, reducing their pollution is vital to avoid potential losses of biodiversity. Caps have also been found to leave microplastics when left in the environment, which may then be present within human food sources, such as seafood, further down the line.

Attempts to create ‘designer’ reusable bottles have been attempted by companies such as Evian through their 2020 collaboration with the late fashion designer Virgil Abloh. However, in order to make these effective in preventing the littering of bottle caps, ideas like this need to be made more accessible and brought into the mainstream.

What are manufacturers doing about plastic bottle caps?

It is still quite taxing to try and find information from UK manufacturers directly on what to do with your bottle caps, or what they are doing with the waste item. Even a direct venture to the website of international consumer goods company, Unilever, does not provide any easy-to-find answers on what to do with the bottle caps. Despite supporting initiatives such as RECOUP’s ‘Pledge 4 Plastics’, which focuses on recycling plastic bottles, there’s little mention of caps.

Many other manufacturers have also focused primarily on the bottles. Following a trial period in April 2018, Highland Spring made its ‘eco bottle’ a permanent fixture of its range the following year. The bottle itself is made from 100 per cent recycled plastic – whilst the company makes it clear that the cap is not created from recycled plastic, both the bottle and the cap are recyclable.

There are some companies who are making changes to their manufacturing processes, whilst addressing the growing number of discarded bottle caps. For instance, Lush UK, the high-street beauty brand, collects plastic bottle caps and sends them to Poole to be recycled into black pots. These pots, which are made of 100 per cent recycled plastic and used as containers for most of Lush’s products, can be returned to the shop for reuse.

In November 2022, The Co-Op announced its commitment to the removal of all coloured milk bottle caps from its shelves. Clear bottle caps reduce colour contamination in the high-density polyethylene (HDPE) stream, allowing for greater ease in the recyclability of materials into food-grade packaging.

Coca-Cola has also made changes to its packaging to try and boost recycling rates. Recently, the company introduced attached or 'tethered' bottle caps across its entire portfolio of drinks, which includes Fanta, Sprite, Dr Pepper and various other popular beverages. Despite having been 100 per cent recyclable for years, these bottle caps often found themselves littered or discarded, an issue that the new attached caps will hopefully mitigate.

Meanwhile, some companies are trying to remove the plastic packaging altogether, which would be an ideal end goal to reduce our mounting plastic waste; Lucozade Sport trialled edible packaging at sports events in August 2018, although it is not yet available to the mass market.

There has indeed been a shift in attitude from food and drink manufacturers away from plastic packaging as a whole; around 130 companies have signed the UK Plastics Pact that promises to eliminate ‘unnecessary’ plastic packaging by 2025. Leading bottle manufacturers also agreed to eliminate plastic packaging by 2030. But, the recycling rate for plastic bottles has plateaued at 57 per cent for the last five years.

The mountain of single-use plastic waste remains high but not insurmountable. While scaling the challenge will require high-level policy intervention and a change of direction from businesses, it is up to the consumer to recycle everything we can – including bottle caps.

What can consumers do?

In the past, councils have told residents that the detached bottle caps cannot just be thrown loose into the same plastic recycling box as plastic bottles. Made from a different plastic polymer to that of a bottle, the two supposedly couldn’t be recycled together.

Yet, the plastic recycling charity Recycling Of Used Plastics Limited (RECOUP), issued a paper in September 2018 putting forward some new information. It said: "It can be confirmed that plastic caps should be left on plastic bottles for recycling. This reduces the potential for the cap to be littered separately, and when attached to the bottle it also allows the cap (as well as the attached neck ring) to pass through the sorting facility and get to a plastic bottle reprocessor.

"This approach simplifies the consumer message, removes confusion, and makes it easier for consumers to recycle bottles. A separated cap will not successfully pass through a sorting facility and will go into a residue fraction for landfill or energy recovery.

"If the cap reaches the bottle reprocessor, they can separate the cap and sell that fraction for recycling. Leaving the cap on does not have any negative effect on the value offered by bottle reprocessors to suppliers of post‐consumer baled bottle material."

Essentially, all consumers have to do is empty and flatten their bottles, leaving on the bottle cap, and then dispose of the bottle and cap into the same recycling plastics box. Once caps are in the plastic (PET) bottle reprocessor, they will be re-granulated, with the material floated off during the wash process and sold on.

But, perhaps the UK should be aiming for a more straightforward, immediate approach. The EU Directive 2019/2024 requires single-use plastic beverage bottles with a capacity of up to 3 litres to be fitted with tethered caps that remain attached to the container throughout their service life from July 2024, ensuring that bottle and cap are not separated ahead of recycling.

Despite bottle caps representing eight per cent (compared to a global six per cent) of collected waste in the UK at the International Coastal Cleanup, similar legislation to the UK is not yet being considered.

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