The evidence desk · Microplastics

Does chewing gum release microplastics?

Two peer-reviewed studies have detected micro- or nanoplastics released from chewing gum or gum base during chewing. That deserves attention. It does not prove that every gum releases the same amount, identify the best brand, or turn a natural-base ingredient list into a laboratory result.

Published 31 August 2026 · Reviewed 31 August 2026 · 9 minute read

The useful short answer

Release has been measured under research conditions. The most informative published comparison found particles from products described as both natural and synthetic, but the brands were not named. No result from that study can responsibly be attached to a specific product on a shop shelf.

Why “gum base” leaves room for questions

Most of a piece of gum dissolves or disperses as you chew. The elastic material left behind is the gum base. On an ingredient list, those two words describe a functional mixture rather than a single substance.

The US Food and Drug Administration’s chewing-gum-base rule illustrates how wide that category can be. Its permitted list includes natural vegetable materials such as chicle and natural rubber, alongside synthetic materials including polyethylene, polyisobutylene and polyvinyl acetate. This is a list of substances that may be used under US rules, not evidence that every conventional gum contains all of them.

That distinction is central to the microplastics question. A generic gum-base label does not reveal the exact polymer recipe. A label that names chicle or mastic resin provides more useful sourcing information, but it still does not measure particles released by the finished product.

What the 2024 study established

In the Journal of Hazardous Materials, Udit Pant and colleagues described a combined spectroscopy approach for detecting micro- and nanoplastics in saliva after chewing gum base for one hour. Automated Raman spectroscopy was used to measure microplastics, while a surface-enhanced Raman method was used to detect smaller particles.

The paper is valuable because it demonstrates that release can be investigated at both micro- and nanoscale, and because it deals directly with the analytical difficulty of finding tiny plastic particles in a complex sample such as saliva. It is not a shopping table. Its published abstract does not provide a named-product comparison that consumers can transfer to a packet in a store.

What the 2025 comparison found

A second paper, published in the Journal of Hazardous Materials Letters, compared five gums described as natural or plant-based with five synthetic gums. The researchers reported a range of 4 to 636 microplastic particles released per gram of gum. Across their measurements, 94% of the particles were released within the first eight minutes of chewing, and the median detected size was 45.4 micrometres.

The result that attracted the most attention was the comparison between categories: the researchers reported no significant difference in the number released by the natural and synthetic groups. They identified polyolefins, polyterephthalates, polyacrylamides and polystyrenes, with polyolefins the most abundant.

Those findings challenge the shortcut that “plant-based” must mean no detectable plastic particles. They do not explain the source of every detected particle. The brands are not disclosed in the paper’s public record, and a category-level result cannot show how an untested product performs. Manufacturing, ingredients, incidental contamination, packaging and the analytical workflow are different questions that require controls and product-specific evidence.

What the research does not tell us

It does not rank brands

Without product names and current batch identifiers, the data cannot be matched to Simply Gum, True Gum, Chicza, Greco Gum, Milliways or any other product. A company’s absence from the paper is not a pass or a failure.

It does not make a medical diagnosis

The studies measured particle release; they did not establish that chewing a particular gum causes disease. Particle count, polymer identity, size, exposure and health effect are separate steps in a risk assessment. We do not turn an exposure experiment into a medical promise or scare claim.

It does not test biodegradability or packaging

A material’s behaviour during chewing is different from how it degrades in soil, water or a composting system. Packaging is another independent layer. A paper box does not prove anything about the base, and a natural base does not prove that every wrapper is plastic-free.

How current natural-base claims compare

First-party pages make several kinds of claim. Simply Gum lists a chicle base made with chicle tree sap, candelilla wax and citric acid. True Gum says it uses chicle from sapodilla trees. Chicza describes its chicle gum as certified organic and biodegradable. Greco Gum lists one ingredient, crystallised mastic-tree resin, and publishes batch-linked checks for botanical identity, heavy metals, pesticides and microbes.

These disclosures are useful, but they support different propositions. Greco Gum’s named tests, for example, strengthen its evidence for resin identity and the listed contaminants; the published panel is not a microplastic-release test. Likewise, a chicle ingredient statement supports natural-base identity, not a claim that the finished product has been screened to a stated microplastic detection limit.

A four-step evidence check

1. Identify the base

Prefer a specific material—such as chicle or mastic resin—over an unexplained “natural gum base.” This answers what the maker says it uses, not what a laboratory detected.

2. Read the scope of any certification

Organic, plastic-free and compostability schemes can have different criteria. Check the named standard, certifier, product and date. Do not assume one certification covers contaminants, particle release and packaging unless its scope says so.

3. Match reports to the product

A strong report identifies the sample or batch, laboratory, method, date, result and detection or reporting limit. A general supplier certificate is weaker than a current report tied to the item being sold.

4. Keep unknowns visible

If a brand has not published product-specific microplastic-release data, the correct verdict is unverified. It is not evidence of a failed test, and a study of unnamed products should not be used to invent one.

What a shopper can reasonably do

Choose products that name their base, disclose the full ingredient list and explain the packaging. Treat a public, batch-matched laboratory report as stronger evidence than broad marketing, while checking exactly what the lab measured. Dispose of every used piece in general waste unless a credible local collection route says otherwise; “natural” is never permission to leave gum on a street or trail.

For the material basics, read our guide to plastic in gum base. To see how disclosure and testing affect scores, review our ranking methodology or compare the current products.

The bottom line

Current research shows that chewing gum can release microplastics under the studied conditions, including from products marketed as natural or plant-based. It also leaves major product-level questions unanswered. Until named finished products are tested with transparent methods and limits, ingredient disclosure and microplastic evidence must stay in separate columns.