Microplastics are solid synthetic polymer particles smaller than five millimetres that do not dissolve and resist breaking down (European Commission, 2023). In cosmetics, they were added on purpose, to scrub, to thicken, to add shimmer and to make a product feel smooth.
The numbers are way larger than most people expect. Researchers who tested facial scrubs estimated that a single use could release between 4,594 and 94,500 microbeads (Napper et al., 2015).
Exfoliating scrubs and face washes are the best-known home for microplastics. They are also found in glitter, make-up, lip products and nail products. A survey of 45 personal care products sold in India found plastic microparticles in 45% of them, across face washes, face scrubs, shower gels and body scrubs (Alex et al., 2024).
Polyethylene is the most common polymer found in cosmetics followed by polypropylene, polystyrene, polyurethane and polycaprolactone. Synthetic waxes are also a problem. Polyethylene wax and microcrystalline wax behave much like banned plastic beads, yet they are not named in most existing microbead bans.
Try this at home. Pick up any product from your bathroom and read the ingredient list. Look for words like polyethylene, polypropylene, polystyrene, polyurethane, microcrystalline wax or polyethylene wax. If any of them appear on the list, there is a good chance you are washing plastic down the drain.
How Microplastics Enter the Environment
Rinse-off products go straight into the sink. From there, the beads travel to a wastewater treatment plant, which was never designed to catch particles this small.
A study in Ljubljana, Slovenia, found that treatment captured about 52% of cosmetic microbeads in sludge. The rest passes through, with an estimated 112,500,000 particles entering the local river each day (Kalčíková et al., 2017). The beads held back in sludge have not disappeared. They have only moved.
Napper et al. (2015) described cosmetic exfoliants as a potentially important, yet preventable, source of microplastics in the sea. The beads also act like tiny sponges. The same study showed that polyethylene microbeads from cosmetics absorbed pollutants such as DDT and phenanthrene from seawater, in amounts similar to other polyethylene particles. A bead that enters a fish can carry chemical contaminants with it.
Polyethylene particles cannot be degraded and are likely to accumulate, so every bead released adds to a stock that keeps growing (Kalčíková et al., 2017).
Biopolymers
Biopolymers are long chains of molecules which can be produced by organisms, or from renewable sources. For example, cellulose, starch and chitosan originate from plants and shellfish, respectively. PHA, on the other hand, are synthesized within bacteria, and function similarly to body fat as an energy storage mechanism in the organism.
Unlike polyethylene, biopolymers degrade back to their constituent parts i.e. CO2, H2O, and biomass when exposed to microorganisms in water and soil.
Major Biopolymer Alternative for Cosmetics
PHA microbeads can replace plastic exfoliants almost one-for-one. They can be produced in sizes from 1 to 150 micrometers with adjustable firmness, which lets a formulator control how gentle or scratchy a scrub feels.
Cellulose beads are widely used as a replacement, though not all of them are equal. The Indian survey found cellulose microbeads in 23.33% of products and noted that their biodegradability was unclear (Alex et al., 2024).
Starch-based powders are another plant option, better suited to soft-feel products than to scrubbing.
Case Study
PHA survived the deep-sea test.
Japanese researchers placed PHA microbeads 757 meters deep in the Pacific Ocean off Misaki Port. Visible degradation appeared within five months. In laboratory oxygen-demand tests, the PHA beads reached 68% to 85% biodegradation in 25 days, in the same range as cellulose at 77% (Hyodo et al., 2024).
How TerraPHA Fits
TerraPHA Biotech is the World’s first non-GMO biopolymer company producing PHA and PHA-based products for multiple sectors in the market. PHA is produced using naturally occurring non-GMO microbial systems and precision-controlled fermentation across a range of renewable carbon sources. Cosmetics is one of the company’s named future application areas.
Frequently Asked Questions
Can PHA replace plastic microbeads in cosmetics?
Yes. PHA can be processed into microbeads with controlled particle size and firmness, making it suitable for applications such as exfoliating scrubs. Unlike conventional polyethylene microbeads, PHA is biodegradable under suitable environmental conditions, including demonstrated degradation in marine environments.
What are microplastics in cosmetics?
Microplastics are small synthetic polymer particles, generally smaller than 5 mm, that can be intentionally added to cosmetic products for exfoliation, texture, thickening, shine, or other functions. Common examples include polyethylene, polypropylene and polystyrene.
References
Alex, R. K., Maes, T., & Devipriya, S. P. (2024). Clean, but not green: Emission assessment, forecast modelling and policy solutions for plastic microbeads from personal care products in India. Emerging Contaminants, 10(3), 100326. https://doi.org/10.1016/j.emcon.2024.100326
European Commission. (2023, September 25). Protecting environment and health: Commission adopts measures to restrict intentionally added microplastics. https://cyprus.representation.ec.europa.eu/news/protecting-environment-and-health-commission-adopts-measures-restrict-intentionally-added-2023-09-25_en
European Commission. (n.d.). Commission Regulation (EU) 2023/2055: Restriction of microplastics intentionally added to products. Retrieved September 21, 2026, from https://single-market-economy.ec.europa.eu/sectors/chemicals/reach/restrictions/commission-regulation-eu-20232055-restriction-microplastics-intentionally-added-products_en
Hyodo, N., Gan, H., Ilangovan, M., Kimura, S., Kasuya, K., Isobe, N., & Iwata, T. (2024). Coastal and deep-sea biodegradation of polyhydroxyalkanoate microbeads. Scientific Reports, 14, 10302. https://doi.org/10.1038/s41598-024-60949-z
Kalčíková, G., Alič, B., Skalar, T., Bundschuh, M., & Žgajnar Gotvajn, A. (2017). Wastewater treatment plant effluents as source of cosmetic polyethylene microbeads to freshwater. Chemosphere, 188, 25-31. https://doi.org/10.1016/j.chemosphere.2017.08.131
Marfella, R., Prattichizzo, F., Sardu, C., Fulgenzi, G., Graciotti, L., Spadoni, T., D’Onofrio, N., Scisciola, L., La Grotta, R., Frigé, C., Pellegrini, V., Municinò, M., Siniscalchi, M., Spinetti, F., Vigliotti, G., Vecchione, C., Carrizzo, A., Accarino, G., Squillante, A., . . . Paolisso, G. (2024). Microplastics and nanoplastics in atheromas and cardiovascular events. New England Journal of Medicine, 390(10), 900-910. https://doi.org/10.1056/NEJMoa2309822
Napper, I. E., Bakir, A., Rowland, S. J., & Thompson, R. C. (2015). Characterisation, quantity and sorptive properties of microplastics extracted from cosmetics. Marine Pollution Bulletin, 99(1-2), 178-185. https://doi.org/10.1016/j.marpolbul.2015.07.029
Not, C., Chan, K., So, M. W. K., Lau, W., Tang, L. T.-W., & Cheung, C. K. H. (2025). State of microbeads in facial scrubs: Persistence and the need for broader regulation. Environmental Science and Pollution Research, 32(17), 11063-11071. https://doi.org/10.1007/s11356-025-36341-3
U.S. Food and Drug Administration. (2022). The Microbead-Free Waters Act: FAQs. https://www.fda.gov/cosmetics/cosmetics-laws-regulations/microbead-free-waters-act-faqs
