What are the nanoparticles found in Coca-Cola?

November 14, 2025 •

3 min read

According to a 2017 study published in Nanotoxicology, fluorescent carbon-based nanoparticles were isolated from commercial Coca-Cola products. These microscopic particles are not intentionally added ingredients but rather form as byproducts of the manufacturing process and our improving ability to detect them.

Quick Summary

This article examines the scientific findings regarding the fluorescent carbon-based nanoparticles found in Coca-Cola, detailing their formation, size, potential health implications, and regulatory context.

Key Points

Carbon-Based Nanoparticles: Scientific research detected fluorescent, carbon-based nanoparticles (carbon dots) in both Coca-Cola and Pepsi.
Byproducts, Not Additives: These nanoparticles are considered unintentional byproducts of the manufacturing process, likely forming from the breakdown of carbohydrates during heating.
Biodistribution in Animal Studies: In mice, the nanoparticles were shown to be absorbed and to accumulate in major organs, including the brain, before being excreted.
Uncertain Long-Term Effects: While acute toxicity was not observed in tested animals, the long-term effects of chronic, low-level ingestion of these particles on human health are still largely unknown.
Lack of Mandatory Labeling: The carbon dot nanoparticles are not listed on ingredient labels because they are byproducts, and regulations in many regions do not require them to be disclosed.
Not Engineered Additives: Coca-Cola has denied using engineered nanoparticles like titanium dioxide (E171), which are sometimes used in other soft drinks.

The Scientific Discovery of Nanoparticles in Coca-Cola

In 2017, a study in Nanotoxicology reported the detection of fluorescent nanoparticles in popular soft drinks, including Coca-Cola and Pepsi-Cola. Utilizing advanced techniques, researchers isolated and characterized these small, uniform, carbon-based nanostructures with an average size of approximately 5.0 ± 0.5 nm. The particles' fluorescence under ultraviolet light aided their initial detection.

Endogenous Byproducts, Not Intentional Additives

The fluorescent carbon-based nanoparticles found in Coca-Cola are considered endogenous, meaning they form within the product, rather than being intentionally added. Researchers suggest these 'carbon dots' are byproducts of chemical reactions during beverage production, not deliberate nanotechnology application. The heating of carbohydrate and sugar ingredients for caramel coloring and flavor can lead to the formation of these nano-sized particles.

Other Nanoparticles in the Broader Beverage Industry

While carbon dots are byproducts in colas, other beverages might contain intentionally added nanoparticles for functional reasons. The table below compares different nanoparticle types potentially found in the beverage industry.


Nanoparticle Type	Common Application	Example Ingredient Name	Coca-Cola Status
Carbon-based fluorescent NPs	Manufacturing byproduct	Not listed as an ingredient	Found as a byproduct
Titanium Dioxide (E171)	Whitening agent, cloudiness	E171, Titanium Dioxide	Denied, often phased out
Silicon Dioxide (E551)	Anti-caking, stabilizing	E551, Silica	Denied, sometimes in drink mixes
Silver Nanoparticles (E174)	Antimicrobial, decorative	E174, Silver	Not typically used in major sodas
Lipid Nanoparticles	Encapsulation of flavors/nutrients	Nano-encapsulated flavors	Rare, used in advanced applications

Major companies like Coca-Cola and PepsiCo have denied using engineered nanoparticles such as nano-sized titanium dioxide (E171). The EU banned E171 as a food additive in 2022 due to safety concerns, prompting its removal from many products in that region. This underscores the difference between unintentional foodborne nanoparticles and regulated engineered additives.

Bio-distribution and Safety Concerns

The Nanotoxicology study on mice, while finding no acute toxicity at the tested dose, provided insights into the nanoparticles' behavior in the body. They accumulated in the liver, brain, and heart within hours. The small size (around 5 nm) allowed them to cross the blood-brain barrier, which is critical for protecting the central nervous system. The fluorescent signal diminished after 24 hours, suggesting the particles were cleared, likely via fecal excretion. Living cells also absorbed the nanoparticles. Experts emphasize the need for more research on the long-term human health effects of chronic exposure to these foodborne nanoparticles due to their unique properties and behavior in the body.

The Lack of Mandatory Labeling

A significant challenge for consumers is the absence of mandatory labeling for nanomaterials in many food and beverages. While the EU requires labeling for engineered nanomaterials, many other countries, including the US, do not. This makes it difficult for consumers to identify products containing nanoparticles from ingredient lists alone. Additives like E171 or E551 might suggest a higher chance of nanoparticles, but it's not certain. Byproduct nanoparticles like the carbon dots in Coca-Cola are not listed under current regulations.

Conclusion

In conclusion, the nanoparticles found in Coca-Cola are fluorescent carbon dots, believed to be unintentional byproducts of manufacturing. Animal studies indicate these particles are absorbed, can cross the blood-brain barrier, and accumulate in organs before excretion. The long-term health effects of chronic human exposure are still under investigation. Due to the lack of labeling requirements for such byproducts, consumers rely on scientific studies for information. Staying informed and choosing beverages with minimal additives are prudent steps for concerned individuals.

Fluorescent nanoparticles present in Coca-Cola and Pepsi-Cola: physiochemical properties, cytotoxicity, biodistribution and digestion studies - https://www.tandfonline.com/doi/full/10.1080/17435390.2017.1418443

"There's Nano in Our Food?" What You Need to Know about Nanotechnology and Food Safety - https://www.centerforfoodsafety.org/issues/303/seeds/blog/3057/theres-nano-in-our-food-what-you-need-to-know-about-nanotechnology-and-food-safety

Frequently Asked Questions

A 2017 study identified fluorescent, carbon-based nanoparticles, often referred to as carbon dots, in Coca-Cola and Pepsi.

No, the carbon dots found are believed to be unintentional byproducts formed during the manufacturing process from the high-temperature treatment of ingredients like sugars.

Animal studies showed that the carbon dot nanoparticles did accumulate in organs like the liver, brain, and heart in mice, although they were largely cleared within 24 hours.

The long-term effects of regular nanoparticle consumption in humans are not yet fully understood. While acute toxicity was not observed in animal tests, some researchers have raised concerns about chronic exposure and the particles' ability to cross biological barriers.

No, because the carbon dots are considered byproducts of manufacturing and not intentionally added ingredients, they are not currently listed on product labels.

Coca-Cola and PepsiCo have denied using engineered nanoparticles like titanium dioxide (E171). E171 has also been banned as a food additive in the European Union.

To reduce potential exposure, consumers can prioritize beverages with shorter, simpler ingredient lists, as these are less likely to contain complex food additives that could be in nanoparticle form.