In the realm of sustainable materials, terms like "biodegradable" and "compostable" are often used interchangeably, leading to significant confusion. To make informed choices, it's essential to understand what these terms mean, how they differ, and the processes involved in breaking down these materials. This article aims to clarify these concepts and shed light on the distinctions between home and industrial composting.

What Does Biodegradable Mean?

Biodegradable simply means that a material can be broken down by biological agents, primarily enzymes. These enzymes can act directly or be produced by microorganisms such as bacteria and fungi.

Biodegradation Process

1. Direct Enzymatic Breakdown: Enzymes can directly break down the material into simpler substances.
2. Microbial Action: Microorganisms, including bacteria and fungi, produce enzymes that degrade the material. This process is commonly referred to as composting when it involves organic waste.

What Does Compostable Mean?

Compostable materials are a subset of biodegradable materials. Composting is the process where organic matter is broken down by microorganisms under specific conditions, resulting in nutrient-rich compost that can be used to enrich soil.

Types of Composting

1. Home Composting: This occurs in a backyard compost bin at ambient temperatures. It involves microorganisms naturally present in the environment that break down organic matter over time.
2. Industrial Composting: This process takes place in a controlled environment with specific conditions such as elevated temperatures and humidity. Industrial composting facilities use specialized microbes and conditions to accelerate the breakdown process.

Industrial vs. Home Composting

The distinction between industrial and home composting is crucial for understanding how compostable materials degrade.

Home Composting

Home composting is the process of breaking down organic materials in a backyard compost bin or pile at ambient temperatures. This method relies on microorganisms naturally present in the environment to decompose materials over time.

• Conditions: Ambient temperatures, natural humidity, and aeration through occasional turning of the compost pile.
• Microorganisms: Naturally occurring bacteria and fungi.
• Timeframe: Typically takes several months to a year for complete decomposition.
• Materials Suitable: Kitchen scraps, yard waste, certain compostable plastics labeled as home compostable.

Industrial Composting

Industrial composting involves a more sophisticated process that requires controlled conditions to efficiently break down materials. This method is used for materials that cannot decompose quickly or fully in a home composting setup.

• Conditions: Elevated temperatures (often above 58°C or 136°F), controlled humidity, and aeration.
• Specialized Microbes: Industrial composting facilities use specific strains of bacteria and fungi that are more efficient at breaking down complex materials.
• Enzymes: Sometimes, specific enzymes are added to accelerate the decomposition process.
• Timeframe: Industrial composting can significantly speed up the process, often completing decomposition in a matter of weeks to a few months.
• Materials Suitable: More complex compostable plastics (e.g., PLA), food waste, and yard waste.

The Challenge of Industrial Composting

While industrial composting is effective in breaking down complex materials, it presents several sustainability challenges:

1. Energy Consumption: Maintaining the high temperatures and controlled conditions in industrial composting facilities requires significant energy input, which can negate some of the environmental benefits of composting.
2. Infrastructure: Not all regions have access to industrial composting facilities, limiting the ability of consumers to properly dispose of industrially compostable materials.
3. Transportation Emissions: Transporting waste to industrial composting facilities can result in additional greenhouse gas emissions.

Given these challenges, there is a growing need for materials that can be composted at home. Home compostable options reduce the reliance on energy-intensive industrial processes and make composting more accessible to a wider population.

Example: Degradation of PLA (Polylactic Acid)

PLA, a popular bioplastic, is derived from renewable resources like corn starch. While PLA is technically biodegradable, it usually requires industrial composting to break down effectively.

1. Conditions: PLA degradation often occurs at temperatures above 58°C (136°F) with specific humidity levels.
2. Microbial Method: Specialized and expensive bacteria and fungi are introduced to facilitate the breakdown process. These microorganisms produce enzymes that degrade PLA into water, carbon dioxide, and compost.
3. Enzymatic Method: Industrial facilities may add specific enzymes directly to break down PLA more rapidly. These enzymes target the polymer chains in PLA, breaking them down into simpler molecules

Without these measure PLA WONT degrade. If you throw it away it'll last decades.

The Confusion Around Biodegradable and Compostable

The overlapping terms and varying requirements for degradation can be confusing for consumers. For instance:

• A product labeled "biodegradable" might not break down in a backyard compost bin and could require industrial composting.
• "Compostable" products may only compost in industrial facilities, not in home compost setups.

The MUSHEE CODE: Simplifying Sustainability

To address this confusion, the MUSHEE CODE offers a simplified and intuitive system for classifying materials based on their source and end-of-life impact. This system makes it easier for consumers to understand the environmental impact of their choices.

LEARN MORE →

Conclusion

Understanding the difference between biodegradable and compostable plastics is crucial for making informed choices about sustainable materials. Biodegradable means the material can be broken down by biological agents, while compostable specifically refers to the breakdown process through composting by bacteria and fungi. The complexity of these terms underscores the need for a simplified system like the MUSHEE CODE, which offers clear, intuitive categories to help consumers understand the environmental impact of their choices.

‍