What are biodegradable plastics?

The term “biodegradable plastic” has generated debate and controversy, especially when it comes to its effectiveness and environmental impact. With growing concerns about sustainability, it is crucial to understand what biodegradability really means and how biodegradable plastics behave in the environment. In this post, we will explore in detail the concept of biodegradable plastics, its advantages, challenges, and its role in recycling and preserving the environment.

The Truth About Plastics and Bioplastics

Plastics are an integral part of our modern lives, found in virtually every aspect of our daily lives. However, the problem arises with their durability, which, while an advantage in terms of use, becomes an environmental disadvantage when disposed of incorrectly. Most traditional plastics, derived from petroleum, are degradable but not biodegradable. This means that over time they break down into microplastics, but do not completely decompose, persisting in the environment for hundreds of years.

On the other hand, biodegradable plastics, also known as bioplastics, are developed from renewable sources, such as plants and animals. These materials have the ability to decompose under suitable conditions, significantly reducing their environmental impact. However, it is important to note that the fact that a plastic is biodegradable does not mean that it will disintegrate in any environment. Specific conditions, such as composting, are necessary for biodegradation to occur effectively.

The Biodegradation Process

Biodegradation is a biological process in which microorganisms, such as bacteria and fungi, break down materials into simpler components, such as water, carbon dioxide, and biomass. This process is essential to the natural cycle of matter and plays a crucial role in the recycling of organic waste.

For a plastic to be considered biodegradable, it must decompose within 180 days, according to international standards. Biodegradation occurs in two main stages:

1. Initial Degradation: At this stage, the polymer chains of the plastic are broken down by factors such as heat, humidity or enzymatic action. The material becomes brittle and begins to fragment.
2. Complete Biodegradation: The resulting small carbon chains are assimilated by microorganisms as a food source, being transformed into natural products such as water, carbon dioxide and biomass. This process varies depending on the environment in which it occurs, and can be aerobic (with oxygen) or anaerobic (without oxygen).

Biodegradability Standards and Certifications

Certification of biodegradable plastics is a vital aspect of ensuring that these materials deliver on their environmental promises. The ASTM D6400 standard, for example, is one of the main guidelines for assessing the biodegradability of plastics, establishing three fundamental criteria:

• Mineralization: At least 90% of the material must be converted to CO2, water and humus through microbiological assimilation within 180 days.
• Disintegration: Less than 10% of material should remain on a 2mm sieve after composting.
• Security: Biodegradable material must not have a negative impact on plants and must contain safe levels of heavy metals, as regulated by the EPA (Environmental Protection Agency).

These standards ensure that biodegradable plastics can be used safely and efficiently, minimizing the risk of environmental pollution.

The Cost Challenge of Biodegradable Plastic

Despite the environmental benefits, biodegradable plastics still face economic challenges. The production cost of these materials is significantly higher than that of traditional petrochemical plastics, due to the technology involved and smaller scale production. However, growing environmental awareness and pressure for stricter regulations have driven the demand for bioplastics.

Furthermore, it is essential to consider the indirect costs associated with the use of traditional plastics, such as pollution, waste treatment and negative impacts on public health. From a global perspective, biodegradable plastics can be more economically advantageous, as they reduce the need for waste treatment and mitigate long-term environmental impacts.

Composting: The Ideal Destination for Biodegradable Plastics

Composting is a natural recycling process that transforms organic waste into a stable, nutrient-rich material known as compost. This process occurs under aerobic conditions and is highly efficient at breaking down biodegradable materials, including biodegradable plastics.

The resulting compost can be used as fertilizer, improving soil quality and reducing the need for chemical fertilizers. In addition, composting helps reduce the amount of waste sent to landfills by reducing the production of methane, a potent greenhouse gas.

The benefits of composting include:

• Regeneration of Poor Soils: Compost improves soil structure and fertility.
• Remediation of Contaminated Soils: Helps clean soil polluted by heavy metals and other contaminants.
• Pollution Prevention: Reduces the need for landfills and incinerators, reducing air and water pollution.
• Reducing Methane Emissions: Composting prevents the production of methane, a byproduct of anaerobic decomposition in landfills.

Biopolymers and Bio-Based Materials

In addition to biodegradable plastics, biopolymers have gained prominence as a sustainable alternative to traditional polymers. Biopolymers are materials produced from renewable sources, such as agricultural crops or biomass, and play a crucial role in reducing dependence on fossil fuels.

Bio-based materials, on the other hand, are those in which the carbon comes from a biological rather than fossil source. These materials are essential for the development of a circular economy, where waste is minimized and resources are reused efficiently.

To be classified as bio-based, these materials must contain “new” carbon, i.e. newly fixed carbon from biological sources. This ensures that the material is truly sustainable and aligned with circular economy principles.

Correct Disposal

Proper disposal of biodegradable plastics is essential to ensure they serve their environmental purpose. While these materials are designed to decompose more quickly and safely than traditional plastics, this only happens under specific conditions, such as those found in composting areas.

In landfills, where there is a lack of oxygen and moisture, the decomposition of biodegradable plastics can be significantly delayed, causing them to lose their positive environmental characteristics. It is therefore essential that these materials are disposed of correctly, preferably in industrial composting facilities.

By adopting conscious disposal practices and promoting recycling, we can maximize the benefits of biodegradable plastics and contribute to preserving the environment. And if you like preserving the environment, you won't believe it How much does it cost to have a complete refresher course available, with a certificate? Check it out by clicking here.

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