Eye drops, dental products, and the hidden plastics we never think about

Have you Thought About...?

If you know about microplastics, you might think they come from plastic bags or bottled water floating in the ocean. If you aren’t familiar, microplastics are exactly what they sound like, tiny plastic particles less than 5 millimeters in size, and often smaller than a grain of salt or the width of a human hair. These fibers are so small that they pass through water systems, ending up in our oceans, our food, and even our bodies.

But have you ever stopped to think about how we are being exposed to microplastics? Beyond the water that we drink or sneaking into our food from plastic packaging, here are some scientific studies on microplastic exposure methods like eye drops, dental products, and more.

More Than Meets the Eye

A study published in Environmental Science & Technology analyzed dozens of previous experiments on microfiber shedding from different fabrics. The results were surprising: cotton clothes actually shed more microfibers than polyester when washed. The reason for this lies in the way natural fibers are spun. Cotton and wool are made of short staple fibers twisted into yarn, which makes them more likely to break off in the wash. On the other hand, polyester is spun from longer filaments that hold together more tightly, so less tends to shed.

Why Isn’t Cotton OK in The Environment?

Researchers in Sydney set out to see if something as ordinary as eye drops could contain microplastics. They tested 60 bottles from 20 different brands using a tool that can spot particles down to 20 microns in size and unfortunately, found 4 samples that contained microplastics. This study provides evidence that commercial eye drops can contain microplastics larger than 20 microns, and since the method used could not detect anything smaller, leaves open the possibility that even more microplastics or nanoplastics could be present and undetected.

This matters because millions of people rely on eye drops every day for chronic conditions like glaucoma and dry eye disease that can require frequent use over months and years. That means repeated and direct exposure to whatever is in the liquid, including microplastics. Understanding whether these particles come from the bottle itself, the cap, or the manufacturing process could be key to reducing them.

Microplastics in Your Mouth?

What happens when you brush your teeth with toothbrush bristles made from plastic or rinse before bed with mouthwash from a plastic container? A study from India found microplastics in every oral care product they checked, including mouthwash, toothbrushes, toothpaste, and floss. Toothbrushes shed the most microplastics, at a rate of roughly 30 to 120 particles per brush, while mouth sprays were lowest at about 0.2 to 3.5 particles per milliliter. Most of what the researchers saw were small pieces under 0.1 millimeter and irregular fragments, with colors ranging from pink and blue to black and clear, with clear pieces the most common.

When they ran further testing, the particles found were composed mainly of polyethylene, nylon, PET, and PBT. Their estimates suggest mouthwash could release tens of billions of particles per day across India, and on a personal level a single person could be exposed to tens of thousands of particles per year from toothbrushes alone.

Figure 1: Abundance and physical characteristics of microplastics observed in oral healthcare products. (Protyusha et al. 2024)

Should You Be Concerned?

Although we do not yet fully understand the health effects of consuming microplastics, research has already linked them to inflammation, hormone disruption, and the potential to carry toxic chemicals into the body. These concerns are especially relevant when microplastics break down into even smaller particles, called nanoplastics, which can enter organs and tissues more easily.

So, the next time you reach for your toothbrush or put in a few drops to soothe dry eyes, it is worth remembering that these everyday routines can also add microplastics to your body. But the number one source of microplastic pollution is still washing machine wastewater, which releases millions of fibers with every load. These different ways to get exposed to microplastics show how deeply plastics have worked their way into the products and systems we rely on every day. Recognizing these hidden pathways is the first step toward protecting both our health and the environment.

How You Can Help

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CLEANR builds best-in-class microplastic filters for washing machines that effortlessly remove the largest source of microplastics into the environment. Its technology, VORTX, represents a breakthrough in filtration, with a patented design that is inspired by nature and proven to outperform conventional filtration technologies by over 300%. The company is building a platform filter technology that enables product manufacturers and business customers to materially reduce their microplastic emissions from impacted in-bound and out-bound fluid streams, including residential and commercial washing machine wastewater, in-home water systems, wastewater treatment, textile manufacturing effluents, industrial wastewater, and other sources. www.cleanr.life

Sources:

Yang, G., Ozkan, J., & Coroneo, M. (2025). Investigating microplastic presence in eye drops using micro-Fourier transform infrared spectroscopy. Cornea, 00(00), 1–7. https://doi.org/10.1097/ICO.0000000000003909
Protyusha, G. B., Kavitha, B., Robin, R. S., Nithin, A., Ineyathendral, T. R., Shivani, S. S., Anandavelu, I., Sivasamy, S., Samuel, V. D., & Purvaja, R. (2024). Microplastics in oral healthcare products (OHPs) and their environmental health risks and mitigation measures. Environmental Pollution, 343, 123118. https://doi.org/10.1016/j.envpol.2023.123118
Ullah, S., Ahmad, S., Guo, X., Ullah, S., Ullah, S., Nabi, G., & Wanghe, K. (2023, January 16). A review of the endocrine disrupting effects of micro and nano plastic and their associated chemicals in mammals. Frontiers in Endocrinology, 13, 1084236. https://doi.org/10.3389/fendo.2022.1084236

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