David Jones, University of Portsmouth

Thousands of tonnes of plastic pollution could be escaping into the environment every year… from our mouths. Most chewing gum on sale is made from a variety of oil-based synthetic rubbers, similar to the plastic used in car tyres.

If you find that thought slightly unsettling, you are not alone. I have researched and spoken about the plastic pollution problem for 15 years. The people I talk to are always surprised, and disgusted, when they find out they’ve been chewing on a lump of malleable plastic. Most manufacturers don’t advertise what gum is made of – they dodge around the detail by listing “gum base” in the ingredients.

There’s no strict definition of synthetic gum base. Wrigley Extra, a chewing gum brand, partners with dental professionals around the world to promote the use of sugar-free chewing gum to improve oral health.

The brand’s Wrigley Oral Health Program states, “Gum base puts the ‘chew’ in chewing gum, binding all the ingredients together for a smooth, soft texture. We use synthetic gum base materials for a consistent and safe base that provides longer-lasting flavour, improved texture, and reduced tackiness.“

It almost sounds harmless. But chemical analysis shows that gum contains styrene-butadiene (the durable synthetic chemical used to make car tyres), polyethylene (the plastic used to make carrier bags and bottles), polyvinyl acetate (wood glue), as well as some sweetener and flavouring.

The chewing gum industry is big business, worth an estimated US$48.68 billion (£37.7 billion) in 2025. Three companies own 75% of the market share, the largest of which is Wrigley, with an estimated 35%. Few reliable statistics are available about the amount of gum produced, but one peer-reviewed global estimate states that 1.74 trillion pieces are made annually.

I examined several types of gum and found that the most common weight of an individual piece of gum is 1.4g. That means that globally, a staggering 2.436 million tonnes of gum are produced each year. About a third (30%) of that weight, or just over 730,000 tonnes, is synthetic gum base.

If chewing plastic isn’t disturbing enough, consider what happens after you spit it out. Most people have experienced discarded gum under bench seats, school desks, and street pavements. But, like other plastics, synthetic chewing gum does not biodegrade and can persist in the environment for many years.

In the environment, chewing gum will harden, crack, and break down into microplastics, but this can take decades. Cleaning it up is not cheap because it is labour-intensive. The average cost is £1.50 per square metre, and estimates suggest that the annual clean-up cost for chewing gum pollution for councils in the UK is around £7 million.

Some efforts have been made to address the problem. In many public locations around the UK, gum collection pots supplied by Dutch company Gumdrop Ltd have been installed to collect and recycle used gum. Signage provided by councils encouraging responsible disposal is also now a regular feature in some UK high streets, and there is a growing number of small producers offering plant-based alternatives.

In the UK, the environmental charity Keep Britain Tidy launched the chewing gum task force in 2021. This collaboration involves three major manufacturers who have committed to investing up to £10 million to clean up “historic gum staining and changing behaviour so that more people bin their gum.”

But here lies the crux of the issue.

The first objective implies that cleaning up gum is a solution to this form of plastic pollution; it isn’t. Manufacturers making a financial contribution to clean-up efforts is like plastic manufacturers paying for litter pickers and bin bags at volunteer beach cleans. Neither addresses the root cause of the problem.

Binning gum is not the solution either. Addressing gum as a plastic pollutant dictates that the prevention of gum pollution should include the well-known tenets of reduce, reuse, recycle, and redesign, like all plastic pollution. It is not only a disposal issue.

Another issue that I have uncovered is the definition. In the two annual reports published by the gum litter task force since its inception, the word pollution is not mentioned. The distinction between litter and pollution is important. By calling chewing gum pollution, the narrative changes from an individual negligence issue to a corporate one. That places an onus for accountability onto the producers rather than the consumers.

Single-use solutions

Like single-use plastic items, chewing gum pollution must be tackled from all angles – education, reduction, alternatives, innovation, producer responsibility, and legislation.

Educating people about the contents of gum and the environmental consequences of those ingredients will reduce consumption and encourage better disposal habits. More transparent labelling on packaging would empower shoppers to make informed choices. Stricter regulations can hold manufacturers to account—a levy tax on synthetic gum can help pay for clean-ups. This would incentivise more investment in plant-based gums and other sustainable alternatives.

We can all reduce the environmental consequences of this plastic pollution by kicking the gum habit, calling on councils to enforce stricter pollution penalties, and encouraging governments to put a tax levy on manufacturers to fund clean-ups and force them to list the contents of gum base.

Throwing away any non-disposable, inorganic products is unsustainable. Chewing gum pollution is just another form of plastic pollution. It’s time we start treating it as such.

David Jones, Sessional Teaching Fellow, School of the Environment and Life Sciences, University of Portsmouth

This article is republished from The Conversation under a Creative Commons license. Read the original article.