With the recent implementation of plastic ban laws in various countries，more and more countries are limiting the use of microplastic in the cosmetics and wash supplies manufacturing since its toxicity and non-degradable property. Correspondingly, our project, seeks to find a substitute for the traditional microplastics——degradable microplastics made by PHA. Our concept focus on the environment (ocean) and health protection, which also gives a support to the 17 Sustainable Development Goals (SDGs). More specifically, our project aligns with SDG 3, SDG 6, SDG 12 and SDG 14.

Good Health and Well-being targets reducing deaths and illnesses from hazardous chemicals and pollution by 2030 (Target 3.9). Good health is foundational to sustainable development, with cosmetic safety directly impacting consumers. This project, replacing traditional microbeads with biodegradable "plastic particles," is vital for safeguarding human health.

• Problem Identifications

Research has found that traditional plastic microbeads, due to their micron-scale size, are difficult to effectively capture in wastewater treatment systems, ultimately leading to their significant release into aquatic environments. These microplastic particles are easily ingested by marine organisms, causing severe consequences such as intestinal blockages and toxic accumulation. More notably, through contaminated seafood, salt, and other food chain pathways, humans may ingest microplastics over the long term. These particles not only pose health risks due to the harmful substances adsorbed on their surfaces but also resist metabolic excretion in the human body because of their tiny size. Additionally, traditional plastic microbeads take centuries to degrade naturally, creating a cumulative health hazard that spans generations.

• Problem

The core challenges currently faced are twofold: on one hand, consumers lack sufficient awareness of the potential hazards of cosmetic microbeads and generally have little understanding of the associated risks; on the other hand, industry regulations and product labeling systems remain inadequate. This dual deficiency in awareness and regulation has led to the ongoing escalation of marine microplastic pollution and potential long-term disruptions to the human endocrine system.

• Solutions

we leveraged synthetic biology to develop PHA-based biodegradable microbeads. These microbeads serve as an environmentally sustainable alternative to conventional plastic microbeads, effectively eliminating microplastic pollution—a known threat to human and ecosystem health. By ensuring rapid biodegradation and maintaining high performance, our product reduces the risk of microplastic ingestion and associated health hazards. Furthermore, our multidimensional strategy emphasizes strengthening industry oversight and improving cosmetic ingredient transparency to empower consumers to make healthier choices. We also prioritize public education on safe and sustainable personal care products, foster industry-academia-research partnerships to advance health-driven innovation, and support the development of science-based standards that promote a greener, healthier industry. Together, these efforts contribute directly to safeguarding public health and advancing global well-being.

Clean Water and Sanitation form the foundation for human survival and development, as well as a crucial safeguard for achieving sustainable development. However, with the intensification of plastic pollution, plastic microbeads from cosmetics are being improperly discharged into rivers, oceans, and other water bodies, severely threatening water quality and hindering the realization of clean drinking water goals. By adopting biodegradable alternatives, we can address water pollution at its source, safeguard water resource security, and promote sustainable consumption.

• Problem Identifications

The persistent presence of plastic microbeads in water systems stems from two fundamental issues. First, we have found that due to their small size, plastic microbeads cannot be fully filtered out by wastewater treatment systems and ultimately enter rivers and oceans. These particles are ingested by marine life, leading to intestinal blockages, poisoning, and even death. Second, regulatory loopholes exacerbate the proliferation of microbeads. Globally, only 37 countries have implemented bans, and regulatory gaps allow products labeled as "plastic-free" to contain polyethylene—a 2023 test revealed that 34% of cosmetics marketed as eco-friendly in the Asia-Pacific region still contained plastic microbeads. The lack of global unified standards has led to the continuous accumulation of microbeads, with the Rhine River alone discharging 4.2 kg of microbeads into the ocean daily.

• Problem

Regulatory loopholes have resulted in 19% of cosmetics labeled as "plastic-free" still containing polyethylene microbeads (2023 test data). Over 80% of countries have not set emission limits for microbeads, and standard monitoring methods cannot detect particles smaller than 0.5 mm. Even in regulated areas like the Rhine River, 4.2 kg of microbeads are still discharged daily, while sewage sludge containing 3,000 microbeads per gram contaminates farmland through fertilizers, highlighting how regulatory gaps continue to harm ecosystems.

• Impacts

The significant increase in microbeads in aquatic environments poses a serious threat to the ecology and public health. Marine organisms often mistake these synthetic particles for food, leading to intestinal blockages, starvation, and the continuous accumulation of toxins in the food chain - studies have shown that over 100 species of aquatic organisms, from plankton to whales, have microplastics in their bodies. At the same time, the porous surface of microbeads is like a chemical sponge, concentrating pollutants in water (such as pesticides and heavy metals) to levels millions of times higher than normal. When ingested by marine organisms, these toxin-laden particles will introduce carcinogens and endocrine disruptors into human diets through the consumption of seafood.

This dual pollution mechanism directly undermines the goal of Sustainable Development Goal 6, as microbeads: (1) complicate wastewater treatment because they are difficult to remove; (2) persist as permanent pollutants even in "treated" water; (3) reintroduce absorbed toxins back into water resources that were supposed to be purified. The damage to marine biodiversity and drinking water safety caused by this has brought an increasingly serious socio-economic burden, especially for coastal communities that rely on fishing and tourism. If not intervened, microbead pollution will continue to erode the recovery capacity of ecosystems and hinder the progress towards global water resource sustainability standards.

• Solutions

To break this cycle, we propose eliminating plastic microbeads at the source by replacing them with biodegradable PHA (polyhydroxyalkanoate) microbeads, engineered through synthetic biology. Unlike traditional plastics, PHA decomposes fully in 6–12 months in natural environments, preventing long-term pollution. Major cosmetic brands have begun piloting PHA, but broader adoption requires cost reductions and policy support. Governments must enforce stricter bans on synthetic microbeads while incentivizing PHA adoption through tax credits. Simultaneously, consumer awareness campaigns can combat greenwashing by promoting third-party certifications for truly biodegradable products.

• Feedback from Relevant Stakeholder

Through questionnaire, Nearly 70% of respondents lack awareness of microplastics in cosmetics (41.76% are completely unaware, and 26.19% have only heard of them but are unclear about which products contain microplastics). Therefore, we need to prioritize addressing this knowledge gap, specifically by: posting educational content on social media platforms like Xiaohongshu and Douyin, explaining common cosmetic categories containing microplastics, detailing their hazards, and highlighting the advantages of PHA microbeads as an alternative material. This will help change consumers' choices and usage of cosmetics, thereby reducing microplastic pollution of water resources.

SDG 12.6 encourages companies, especially large and multinational ones, to adopt sustainable practices and integrate sustainability information into their reporting cycles. Our team uses synthetic biology to colibacillus into biodegradable microplastic particles. Large enterprises only need to replace 1% of traditional plastic in their formulas to report reduced non-biodegradable microplastics in annual sustainability reports, aligning with SDG 12.6—making small changes visible, quantifiable, and amplifiable. SDG 12.a supports developing countries in strengthening scientific and technological capacities for sustainable production and consumption. We’ve simplified experimental ideas into accessible science communication materials, sharing them via online platforms and volunteer networks to help them adopt greener methods with local resources, fostering global sustainability.

Responsible consumption and production mean that enterprises produce less waste at the source and consumers do not litter at the end. The microplastic particles we have made can be consumed by microorganisms within 90 days. If cosmetic companies use them to replace traditional plastic microbeads, a facial cleanser will no longer be "century-old garbage" but become a part of a sustainable cycle.

• Problem Identifications

Many facial cleansers and scrubs contain plastic microbeads, which will flow into the sewer with the water after use. These microbeads are difficult to decompose by nature and will remain in the ocean and rivers for a long time, eventually entering the food chain when miseaten by animals. This non-biodegradable microsphere not only harm water resources but also causes serious pollution to the environment and affects the ecological balance. The traditional production methods of cosmetics often overlook the long-term impact of these microbeads on the environment, leading to the waste of resources and environmental damage.

When consumers purchase cosmetics, they usually only focus on the efficacy and price of the products, and seldom consider their sustainability. Cosmetics packaging and publicity tend to also won't provide information about the environmental impact of product, consumer is hard to make green choices. The lack of understanding of sustainability, make it hard for consumers to link daily consumption behavior and environmental protection. The information asymmetry causes consumers even with environmental protection consciousness, is also difficult to make a green choice in the actual purchase.

• Problem

Most cosmetic enterprises take cost and profit as the core, giving priority to how to reduce production costs and increase product sales. Sustainable production methods often require additional investment and technology upgrade, this is seen as an additional burden, rather than a competitive advantage. Enterprises lack of incentive to adopt more environmentally friendly materials and production process, because it may increase the cost and impact profits. This kind of cost-benefit oriented production mode, led to the neglect of environmental impact, hindered the process of sustainable development.

• Solutions

Our project encompasses multiple initiatives to advance sustainability in the cosmetics industry, including promoting the adoption of PHA-based biodegradable microbeads by encouraging manufacturers to integrate them into formulations—this substitution directly reduces the production and discharge of persistent plastics, enabling a transition towards greener production practices; establishing a transparent and credible certification and labeling framework for sustainable cosmetics, where clear labeling empowers consumers to identify environmentally responsible products and make more informed purchasing decisions; simplifying the manufacturing process to make biodegradable microbead production accessible to companies in developing countries and small and medium-sized enterprises, with educational materials and training resources further supporting the global adoption of sustainable practices; and advocating for the integration of microplastic reduction metrics into corporate sustainability reports, allowing companies to publicly demonstrate progress aligned with SDG 12.6 and enhancing accountability.

• Feedback from Relevant Stakeholder

Our team have interviewed Yifan Zhang, who currently serves as Director of Youth Mobilization and Youth Relations at the United Nations Sustainable Development Goals and Leadership Development Center. He said the project can play a positive role in the early and middle stages of production. By optimizing the production mode, it reduces the use of plastic microbeads, which may cause pollution, belonging to responsible improvement of the production link, thereby promoting responsible consumption. It should be noted that its positive impact on the environment is indirect, mainly achieved by preventing microplastic pollution, rather than directly purifying the already polluted environment.

Yifan Zhang give us some advice. He recommended us to quantify the carbon emission reduction potential of PHA microbeads through Life Cycle Assessment (LCA) to obtain policy support. In the evaluation process, it is necessary to comprehensively demonstrate the carbon emissions in the technical links, clearly sort out the carbon footprint of the production links. Instead of only considering the later stages, an overall calculation and demonstration should be carried out by unit. It should also be noted that the promotion of PHA microbeads does not necessarily lead to emission reduction. Also, for the main audience of cosmetics (women, need to be subdivided by age), select appropriate communication methods, platforms and means (for example, platforms such as Xiaohongshu can be used for young groups). The communication content should formulate different strategies based on the concerns of the audience (such as environmental issues, skin problems, etc.). Through effective public education, improve consumers' acceptance of PHA microbeads and accelerate the achievement of SDG12 goals. What’s more, in addition to cosmetics enterprises, scientific research institutions and policy makers, the participation of stakeholders such as BOL (suppliers, design partners, customers), MOL (retailers, logistics partners, service partners, customers), EUL (recyclers, EOL service partners, customers) is crucial for the large-scale implementation of the project. In the promotion process, it is necessary to balance the demands of all parties, such as paying attention to the cost control needs of enterprises and the safety requirements of the government, to ensure the protection and balance of interests in the production chain, and help the smooth development of SDG12-related practices.

Additionally, during our conversation with Ms. Peng (Marketing and Sales Manager at SGS China Guangzhou Branch), she emphasized that in China, some regions provide policy support for the commercialization of PHA microbeads, but most provinces lack sufficient support. In terms of market standards, we lack a unified domestic standard, and companies mostly follow international rules. We need to collaborate with universities and factories to improve technology and obtain third-party authoritative certification to ensure product safety, thereby meeting the requirements of domestic and international markets.

SDG 14.1 aims to prevent and significantly reduce all marine pollution, especially from land-based activities such as marine debris and nutrient pollution, by 2025. SDG 14.a, in line with the guidelines of the Intergovernmental Oceanographic Commission, promotes the dissemination of scientific knowledge, the building of research capabilities, and the transfer of marine technologies to improve ocean health and enhance the contribution of marine biodiversity to the development of developing countries, particularly small island developing states and least developed countries. The health and diversity of underwater organisms are crucial for maintaining marine ecological balance, which is a cornerstone of sustainable development, supporting planetary health, coastal communities, and ocean-dependent economies. Our project aims to replace traditional plastic microbeads in cosmetics with biodegradable "plastic particles" produced by microorganisms, thereby reducing marine pollution and helping to protect underwater organisms and marine ecosystems.

• Problem Identifications

After a large amount of cosmetics which contained the plastic microbeads are used, the beads entered the ocean with the wastewater through the drains, and finally lead to an increasing and widespread distribution of the plastic in the ocean.

• Problem

Many cosmetic industries lack effective measures for controlling the discharge of the plastic beads, more pollutions will occur.

The public has insufficient awareness of microbead pollution in the ocean, and has not formed an adequate social supervision pressure, this will lead to an uncontrollable environmental pollution, and even cause a huge economic loss.

• Impact

Plastic microbeads, as tiny plastic particles, have become invisible killers of marine ecosystems, their harm permeating all links of the marine food chain and directly impacting the core goals of SDG 14 such as "reducing marine pollution" and "protecting marine biodiversity".

Firstly, the plastic microbeads may directly threat to marine life survival. They usually less than 5mm in diameter, which are easily mistaken for food and ingested by marine organisms such as plankton, shellfish, and fish. Once inside the organisms, the microbeads cannot be digested, blocking the digestive tract and preventing the organisms from absorbing nutrients, eventually leading to death from malnutrition or organ failure. For example, studies have found that after ingesting microbeads, coral polyps efficiency decreases by 40% and their growth rate slows significantly.

Secondly, plastic microbeads may also cause the enrichment of harmful substances and food chain transmission. The surface of them has strong adsorption properties, attracting heavy metals (such as lead, mercury) and persistent organic pollutants (such as PCBs) in the ocean, with an adsorption capacity 100-1000 times that of seawater. When marine organisms ingest these "toxic microbeads", harmful substances accumulate in their bodies and are enriched through the food chain. Small fish that consume microbeads may have a 10-fold increase in harmful substance concentrations, and seabirds or marine mammals that prey on these small fish can see concentrations rise to 100-1000 times the original level, threatening not only marine life but potentially human health through seafood.

• Solutions

Our project, combined with multiple initiatives, directly addresses the core goals of SDG 14: "preventing and reducing marine pollution" and "protecting and restoring marine ecosystems".

Innovative breakthroughs in degradable "plastic particles: Our developed degradable "plastic particles" are made from natural biomass (PHA created by the escherichia coli). They can be gradually decomposed into carbon dioxide and water by enzymes secreted by microorganisms in the marine environment, with a degradation cycle hunreds time shorter than traditional plastic microbeads. The decomposition process produces no toxic substances, and the particles gradually lose their ability to adsorb harmful substances, reducing the risk of ingestion and food chain enrichment.

This project, using microbially synthesized biodegradable PHA microbeads to replace traditional microplastics, closely aligns with SDGs 3, 6, 12, and 14:

SDG 3: Reduces health risks from microplastics entering the human body via the food chain, helping lower pollution-induced diseases.

SDG 6: PHA microbeads degrade rapidly, reducing water microplastic pollution at the source and protecting clean water resources.

SDG 12: Promotes sustainable materials in the cosmetics industry, simplifies technology popularization, and advances responsible production and consumption.

SDG 14: Significantly reduces marine microplastic accumulation, lessens harm to marine life and toxin enrichment, aiding ocean protection.