EU Biodegradability Regulations for Agricultural Applications

Regulations are shaping the agriculture industry’s use of plastic.

Plastics have various uses in agriculture. For example, agricultural films, waterproofing sheets, irrigation systems, control-release fertilizers, and seedbeds help enhance farm productivity. This is especially true in areas with conditions that limit their agricultural potential. As the industry shifts to reduce waste and comply with regulations, sustainable alternatives are of growing interest to stakeholders.

You can also read: Transparent Sprayable Films: Advancing Agricultural Growth.

Choosing low-impact materials and avoiding incorrect practices at product end-of-life, such as burning or burial, can help reduce impact. The European Commission has adopted various regulations to promote sustainability in agriculture, particularly around plastic products. In Delegated Regulation (EU) 2024/2770, relevant polymers must reach 90% degradation in soil 48 months after end-of-use. The regulation states additional specifications for biodegradation in water.

Soil Biodegradability Assessment

ISO 17556 specifies the soil biodegradability of plastics. This method uses the following formulas to measure biodegradation using oxygen demand or the amount of evolved CO2. Using these formulas, you can calculate the biodegradation test material (D) percentage at time t.

• Oxygen demand:

  In this formula, BT represents the test material, BB the blank, and T is the theoretical oxygen demand. 𝜌𝑇 is the concentration of the test material in the soil.

   

• Evolved CO₂:

  Here, m represents the amount of CO2, in mg, evolved from the test material. ThCO2 is the calculated theoretical amount of CO2 evolved from the test material.

The ASTM D5988-d is equivalent to the ISO 17556, with different validity criteria. Natural and thermoplastic starch (TPS) and poly(butylene succinate-co-adipate) (PBSA), polyhydroxybutyrate (PHB), and cellulose are examples of soil biodegradable biopolymers.

Water Biodegradability Assessment

ASTM D6691 focuses on plastic biodegradability in marine water, also using oxygen demand or evolved CO₂ as the testing parameter. For freshwater, researchers can use ISO 14851 and ISO 14852 standards to evaluate biodegradability. Biopolymers that degrade in freshwater are less numerous than those that degrade in soil due to less harsh conditions. A 2018 study showed that, following ISO 14851, only PHB and TBS met the pass criteria for ultimate biodegradation.

Reducing Impact in the Field

As technology develops to adhere to these regulations, the plastics industry may develop new, more sustainable formulations. Plastic mulching films, for example, inhibit the growth of weeds, protect soil from erosion, and keep the soil moist. At the end of cultivation, these films become too contaminated (organic/inorganic matter, fertilizer, etc.) for reuse or recycling. Improper disposal, such as burning or abandonment, of the films causes environmental problems—a marked drawback of their disposal options. Industry adherence to biodegradability regulations can help farmers avoid contributing to this issue. That way, they can continue to reap the benefits of agricultural plastic products, with more sustainable technology.