Frequently Asked Questions & Answers:

What are bioplastics? Are biobased plastics automatically biodegradable?

Bioplastics are a young and innovative industry that is rapidly developing. The growing ecological awareness and the knowledge of the finite nature of fossil resources are just two of the factors significantly contributing to the growth of bioplastics.

With their clear advantages in climate protection and resource conservation, bioplastics are an essential component of the bioeconomy and play a crucial role in a resource-efficient, closed-loop economy.

Bioplastics are a large family of materials that can vary widely in type, properties, and usage possibilities: Bioplastics are either biobased, biodegradable, or both, meaning biobased and biodegradable.

The majority of bioplastics are durable (i.e., non-degradable), biobased materials used for packaging and in many long-lasting applications, such as in the textile, automotive, electronics, and construction sectors. These biobased plastics (e.g., biobased PE or biobased PET) can be recycled in existing recycling streams for conventional plastics.

The group of biodegradable and compostable plastics offers a very specific added value through organic recycling (i.e., industrial composting and anaerobic digestion) as an additional waste recovery option. When compostable plastics are organically recycled, valuable biomass (humus) is created, which in turn promotes the growth of new plants.

What is the difference between biodegradable and compostable plastics?

The term “biodegradable” simply describes that a material can undergo a natural process in which microorganisms such as bacteria and fungi convert the material into water, CO2, and biomass under aerobic conditions.

Whether a plastic is biodegradable or not depends solely on its chemical structure and not on the raw material from which the plastic is made. This means that biodegradable plastics can be made from renewable resources, but they do not have to be.

Statements about biodegradability should therefore never be made without specific reference to the environment, the timeframe in which the process takes place, and the intended waste disposal option.

Industrially compostable plastics are developed for biological degradation under specific conditions (temperature, humidity, etc.) in industrial composting facilities and anaerobic digestion plants (according to the European harmonized standard DIN EN 13432).

Additionally, there are materials designed for home composting (home/garden compost) or for biodegradation in soil (DIN EN 17033). All these options have corresponding certification and testing schemes, as well as labels, to prove that the materials fully degrade in their intended environments.

As part of the certifications, the materials must pass extensive ecotoxicity tests according to EU standards to ensure that the compost is clean and safe for reuse as humus.

Can I dispose of compostable plastic products in the organic waste bin?

In Germany, only certified industrially compostable organic waste collection bags are allowed for disposal in the organic waste bin, according to the federal organic waste regulation. Municipalities and public waste disposal companies may decide differently as to whether the collection bags are approved for disposal in the organic waste bin in their respective areas. All other compostable plastic applications are not allowed in the organic waste bin in Germany.

How quickly do the organic waste collection bags biodegrade?

Certified industrially compostable organic waste collection bags degrade just as quickly in technical composting as organic kitchen waste. The organic waste collection bags were optimized based on this. 

The organic waste collection bags must degrade only 90 percent according to the EN 13432 standard. What happens to the remaining 10 percent? Do they remain as microplastics?  

No, no plastic particles remain in the soil. Just as humans exhale carbon dioxide when they “digest” food, the EN 13432 standard requires the measurement of the carbon dioxide produced as proof of degradation. Fungi and bacteria do not convert the entire biomass they “digest” into carbon dioxide; they also use parts of it to grow and reproduce. These are the remaining 10 percent. 

Is only the biogenic portion of the biodegradable plastics degraded?

No, even the synthetic components made from fossil resources are metabolized and thus degraded by microorganisms. Microorganisms do not distinguish where the food comes from but only whether it provides energy and building materials for their cells. The degradation of all components must be individually proven in the certification according to EN 13432.

How can you recognize compostable bags that have been tested and certified according to EN 13432?

By the printed seedling symbol and the registration number of the certificate, which are clearly visible on the bags.

Do the certified industrially compostable organic waste bags also degrade during anaerobic digestion?

During anaerobic digestion, different microorganisms are active than during composting. They do not find the organic waste bag as appetizing. However, after the digestion stage, the digested material undergoes composting to mature compost. Many trials have shown that the organic waste bags fully degrade during this step.