World Environment Day on 5 June 2025 is calling for us to come together and fight plastic pollution. After all, over 70% of the Earth's surface is covered by water, yet there are already hundreds of thousands of plastic particles floating in every square kilometre of our oceans. More than 19 million tonnes of plastic waste end up in our waters every year. This waste accumulates as macroplastics and, more importantly, as tiny microplastics, harming fish, birds, corals and, ultimately, humans too.
Microplastics - an environmental problem in our waters
Microplastics are tiny plastic particles (less than 5 mm) that enter the water. They can come from the breakdown of larger waste items, or they can be added directly to products such as scrubs in the form of microgranules. Key sources include cosmetics containing microbeads, such as scrubs, as well as tyre and synthetic clothing abrasion. Tyre abrasion is considered the largest source of microplastics in Germany. The consequences are serious.
- Sources: Cosmetics and washing machines release microparticles into river and sea water.
- Riscs: Microplastics absorb environmental toxins. These include heavy metals, PCBs and DDT. They then release these toxins again. This causes pollutants to enter the food chain.
- Toxic additives: When plastic breaks down, it releases harmful chemicals such as bisphenol A, phthalates and flame retardants, which have a hormonal effect and pollute ecosystems.
Overall, microplastics pose a significant environmental threat. They have already been detected in all the surface waters studied worldwide, and are present in the rivers, lakes and seas in quantities amounting to thousands of tonnes. Due to their tiny size, fish, mussels, plankton and other organisms ingest the particles by mistake, thereby accumulating hazardous substances in the food chain.
Biodegradable bioplastics in water
Unter Bioplastics are plastics that are made entirely or partially from renewable raw materials and/or are biodegradable.
Find out more here: https://www.golden-compound.com/en/archiv/biokunststoffe-2/
Ideally, biodegradable plastic should decompose completely into carbon dioxide, water and biomass by microorganisms. In practice, however, this is usually only possible under specific conditions. Many bioplastics (e.g. polylactic acid, or PLA) require the high temperatures and aeration found in industrial composting plants, and remain practically stable in cool water or seawater. A recent study shows that a commonly used compostable bioplastic remains virtually unchanged even after 14 months in seawater.
Therefore bioplastics and water Biobased plastics are not a solution per se: although they prevent the use of fossil raw materials, they must be disposed of correctly. They are usually only degraded in an environmentally friendly way in the soil or in sewage sludge, but not automatically in rivers or oceans. In principle, however, degradation in water is possible - provided oxygen and microorganisms are present. The German Institute for Standardisation (DIN) defines biodegradation precisely in such a way that microorganisms can break down the material. convert to CO₂ and water under oxygen supply (and to CO₂ and CH₄ in the anaerobic state). Only if these conditions are met can a biodegradable plastic leave the water cycle.
However, products made from bioplastics often end up on beaches, carried there by the currents of rivers or oceans. There are then enough microbes in the soil necessary for decomposing biodegradable plastics, such as bio-PBS. Therefore, bioplastics are always a better option than conventional plastics.
Water consumption in plastics production
Conventional plastic production is extremely water-intensive. Around 2.000 litres […] litres of water are required to produce 1 kg of new plastic. This high water consumption is caused by cooling and cleaning processes in refineries and polymer plants, as well as by the dilution and treatment of wastewater containing released pollutants. For comparison: According to study participants, around 10 litres of water are used to produce one kilogram of conventional polyethylene (HDPE), but other studies estimate the total water footprint to be significantly higher. One thing is certain: Plastic production uses enormous amounts of water, which could contribute to water scarcity if plastic consumption continues to increase.
Effects on water quality and the environment
Apart from its use, conventional plastic has a direct impact on water quality. Plastic particles block light and hinder the oxygen supply to aquatic plants and animals. Most importantly, however, plastics release dangerous chemicals into the water. Plastic that has decomposed in the sea releases up to 1,000 different additives that can damage the genetic makeup and hormone balance of fish, amphibians, and invertebrates. Microplastics accumulate in plankton, mussels and fish, meaning toxins introduced into the food chain also end up in domestic aquaculture or fishery products. Nanoplastics, which are difficult to filter out of drinking water, have even been found in many waterways, posing an additional environmental and health risk. Consequently, our rivers and lakes are gradually becoming polluted and may lose their ecosystem functions in the long term.
Recycling and water consumption
Apart from its use, conventional plastic has a direct impact on water quality. Plastic particles block light and hinder the oxygen supply to aquatic plants and animals. Most importantly, however, plastics release dangerous chemicals into the water. Plastic that has decomposed in the sea releases up to 1,000 different additives that can damage the genetic makeup and hormone balance of fish, amphibians, and invertebrates. Microplastics accumulate in plankton, mussels and fish, meaning toxins introduced into the food chain also end up in domestic aquaculture or fishery products. Nanoplastics, which are difficult to filter out of drinking water, have even been found in many waterways, posing an additional environmental and health risk. Consequently, our rivers and lakes are gradually becoming polluted and may lose their ecosystem functions in the long term.
At the same time, far too little plastic is still recycled properly. In our opinion, this is what perfect recycling looks like:
- Option 1: Natural recycling, e.g. for plant pots
The plant is cultivated in a biodegradable pot and, ultimately, ends up in the soil with the plant at the end user's home. There, the pot decomposes into biomass, carbon and water, and the plant does not experience root breakage. - Option 2: Closed-loop recycling
All our compounds are recyclable in their own cycle. This is mainly due to the fact that there is no general cycle for biopolymers or natural fibre materials. Nevertheless, it is possible - just as with conventional plastics - to enable a recycling loop with up to 7 cycles. For example, a coffee cup could be made from GC green 71 MI T30 and used for many years. Before it is disposed of in residual waste, we could granulate it again and remanufacture it into exactly the same coffee cup. However, this would require a closed cycle, which we can only dream of so far.
Sustainable plastic alternatives and future opportunities
Many developments demonstrate this. It is possible to produce sustainable plastic alternatives. Bioplastics are increasingly being produced from waste materials rather than precious raw materials. One example is the bioplastic we use. Bio-PBS (Polybutylene succinate based on corn starch). In this process, maize starch is converted into succinic acid and 1,4-butanediol. These are then polymerised to form a fully compostable polyester. Bio-PBS offers the advantages of good material properties, such as strength and a barrier against oxygen and water, as well as biodegradability, making it a promising alternative to conventional polypropylene (PP).
At the same time, we are working to minimise our use of bioplastics by producing compounds made from bio-PBS and mineral fillers, as well as sunflower seed shells. This enables us to replace some bioplastics with natural raw materials. In the case of sunflower seed shells in particular, we utilise a waste product from the food industry that can be put to good use.
Outlook
The relationship between plastics and water is complex: Conventional plastics pollute bodies of water in the form of waste, micro- and nanoparticles, and persistent pollutants. They also consume vast quantities of water during production. However, recycling and bio-based materials offer significant improvements in this regard. Recycling drastically reduces water consumption within a circular economy, while bio-based, compostable plastics made from renewable resources help conserve fossil fuels. In particular on World Environment Day 2025, it is clear that we need to take action: We must avoid plastic waste, recycle consistently, and promote sustainable alternatives. For consumers and companies, this means choosing reusable products over disposable ones, buying local products with less packaging, improving recycling and supporting innovative materials such as bio-PBS and organic polymers from waste materials. By doing so, we can strengthen the protection of our water and environment, and finally reduce the environmental impact of microplastics.
Together for a better future
