The Basics of Bioplastics

Of the 40 million tons of plastic waste produced in the US in 2021, 85% ended up in landfills. Despite growing awareness of the crisis, recycling volumes are dropping — only 6% of municipal plastic waste was recycled in 2021, down from 9% in 2018. Our waste production outpaces our capacity to process it, so much of it gets shipped to other countries that lack adequate infrastructure to handle it safely.

Bioplastics have emerged as an alternative, but the term covers a wide range of materials with very different properties. Understanding what bioplastics actually are and what to look for when choosing them is the first step toward decisions that hold up under scrutiny.

What Are Bioplastics?

Bioplastics are plastic-like materials made from organic, plant-derived raw materials — corn starch, sugarcane, tapioca, agave, wheat, vegetable fats, and milk proteins — rather than petroleum. They can be molded, extruded, and formed into many of the same products you’re used to seeing made from traditional plastic: cups, cutlery, food containers, packaging films, and more.

“Bioplastic” is an umbrella term covering several distinct material types with different chemical structures and different end-of-life pathways. Some are certified compostable. Others are chemically identical to conventional plastic and will persist in a landfill just the same.

Most bioplastics start with plant starch or sugars from corn, sugarcane, or cassava. Microorganisms ferment those sugars into organic acids (like lactic acid), which are polymerized into materials like PLA (polylactic acid). Others are derived from cellulose or vegetable oils. A biobased origin does not automatically mean a material is compostable — that depends on the material’s chemistry and certified end-of-life pathway, not where the ingredients came from.

Types of Bioplastics

Not all bioplastics are the same. Here are the four main types you’re likely to encounter.

PLA (Polylactic Acid)

PLA is the most commercially widespread bioplastic, made from fermented plant starch. You’ll find it in single-use cups, food containers, cutlery, and 3D printing filament. PLA is certified compostable under industrial conditions when it meets ASTM D6400 (US) or EN 13432 (European) standards. It does not break down in home compost bins or standard landfill conditions.

PHA (Polyhydroxyalkanoate)

PHA is produced by bacteria fed on plant sugars or waste oils. It’s more flexible than PLA and can break down in a wider range of conditions, including soil and marine environments. Applications include medical devices, agricultural films, and specialty packaging. PHA is currently more expensive and less commercially widespread than PLA.

Starch-Based Bioplastics

These materials are made from plant starch blended with other polymers. Common applications include loose-fill packaging, disposable bags, and agricultural mulch films. Compostability varies widely by formulation — the certification is what matters, not the material category alone.

Biobased Polyethylene and Other Organic Polymers

Bio-PE is made from sugarcane ethanol and is chemically identical to conventional polyethylene. That means it is not compostable and will persist in the environment the same way conventional PE does. This is why “biobased” and “compostable” are not interchangeable terms.

Biobased, Compostable, and Materials That Claim to Break Down Naturally: What’s the Difference?

These terms are used interchangeably in marketing, but they describe fundamentally different things.

Biobased

Biobased describes where a material comes from, not what happens to it after use. A biobased product is made partially or entirely from organic matter, but the term says nothing about end-of-life — it can still persist in a landfill for decades. And bioplastics can also be made from petroleum, so “bio” doesn’t guarantee plant origin.

Compostable

Compostable materials break down into nutrient-rich biomass through a microbial process — no chemical treatment, no toxic residue — in as little as 90 days under industrial conditions. To carry that label legitimately, a product must be certified to ASTM D6400 (US) or EN 13432 (Europe). BPI certification (US) and TUV Austria OK Compost certification are the marks to look for. Industrial composting requires sustained temperatures of 55–60°C, controlled moisture, and adequate oxygen — conditions home compost bins typically do not replicate.

Learn more about composting vs. recycling

Materials That Claim to Break Down Naturally

Some materials are marketed with breakdown claims but without composting certification. Without a defined timeframe or third-party testing, these claims are difficult to verify. Uncontrolled breakdown can take years and may release harmful amounts of methane and CO2. That’s why we focus on certified compostable materials: the standard is clear, the testing is independent, and the outcome is defined. Proper disposal is essential.

Claim	What It Tells You	What It Doesn’t Tell You
Biobased	Made from plant or organic materials.	How it breaks down after use.
Compostable (certified)	Breaks down completely in 90–180 days under industrial conditions.	Whether home composting works.
“Breaks down naturally” (uncertified)	A marketing claim.	Timeframe, conditions, or safety of breakdown.

How Long Does It Take Bioplastics to Break Down?

The answer depends entirely on the material type and the disposal conditions. Here’s what the evidence shows:

• Certified compostable bioplastics (e.g., PLA): 90–180 days in a certified industrial composting facility operating at 55–60°C with appropriate moisture and oxygen levels.
• In home compost: Most certified compostable bioplastics do not break down reliably in home compost. Conditions are too variable and temperatures too low for standard PLA.
• In a landfill: Breakdown is severely slowed without oxygen and moisture. Compostable materials still outperform conventional plastic in a landfill, but this is not the intended disposal pathway.
• In the environment (soil, water): PLA and most starch-based materials are not designed to break down in open environments. PHA is an exception, with broader breakdown potential in soil and marine conditions.

The conditions matter as much as the material. That’s why certification and proper disposal pathways are the two most important things to look for when choosing bioplastic products.

Where Are Bioplastics Used Today?

Packaging remains the dominant application: food serviceware (cups, bowls, cutlery, clamshells, food wrap), consumer goods packaging, agricultural mulch films, PHA-based medical devices, PLA-based 3D printing filament, and emerging textile applications. For everyday consumers and foodservice operators, certified compostable food packaging is where the choice has the most direct impact. Explore our certified compostable packaging.

The Real Environmental Picture

We believe transparency builds trust, so here’s an honest look at both sides.

Benefits:

• Reduced dependence on petroleum feedstocks — every unit of plant-based material displaces fossil-fuel-derived resin.
• Lower carbon footprint across the production lifecycle, though figures vary by material type, production method, and energy source.
• Certified compostable materials close the loop: when properly composted, they produce no landfill waste, leave no toxic residue, and the resulting compost enriches soil.

Limitations to understand:

• Composting infrastructure gap. Most US municipalities don’t yet have industrial composting drop-off programs, and availability varies widely by region.
• Contamination risk. Compostable bioplastics placed in conventional recycling bins can contaminate the recycling stream.
• Land use and feedstock competition. Growing crops for bioplastic production can compete with food supply — one reason waste-stream feedstocks (like post-tequila agave fiber) are a more sustainable sourcing model.
• Unverified claims. Without certification, a "bioplastic" label is not enough. The FTC Green Guides exist to prevent vague or misleading environmental claims.

The solution isn’t to dismiss bioplastics — it’s to demand certification, support composting infrastructure, and make choices based on evidence. Building a compostable mindset starts with understanding both sides.

How to Identify Genuinely Compostable Products

Look for Certification Marks

Two certification marks carry the most weight: BPI Certified Compostable (tied to ASTM D6400) and TUV Austria OK Compost Industrial (tied to EN 13432). These marks mean the product has been independently tested — the claim is not self-declared. When checking packaging, look for the resin identification code — the small triangle with a number inside.

Plastics labeled 1, 2, or 5 have the highest recyclability. Many bioplastics carry a #7 and show “PLA” beneath the symbol.

Find a Drop-Off Facility

Certified compostable products need to reach an industrial composting facility. Your local waste management authority can direct you to drop-off points, and some stores participate in drop-off programs. Supporting a circular economy means routing materials through the right system — understanding your disposal options is the first step.

Avoid Cross-Contamination

Keep compostable packaging out of conventional recycling bins — PLA can contaminate recycling streams if mixed with conventional plastics. If composting isn’t available in your area, general waste is still preferable to contaminating recycling. And avoid polystyrene (#6) — it’s among the worst offenders.

FAQ

What Is the Difference Between Bioplastic and Regular Plastic?

Conventional plastic is made from petroleum. Bioplastic is made from plant-derived organic materials like corn starch, sugarcane, or agave. Both can be molded into similar products, but certified compostable bioplastics can be broken down into non-toxic biomass under the right conditions — something petroleum-based plastics cannot do.

Are Bioplastics Actually Better for the Environment?

Certified compostable bioplastics reduce petroleum dependence and can close the material loop when composted correctly. But without proper disposal infrastructure and certification backing the product, the benefit is limited. Look for BPI or TUV Austria marks, and make sure you have access to a composting facility that accepts the material.

Can Bioplastics Be Composted at Home?

Most certified compostable bioplastics require industrial composting conditions — sustained heat of 55–60°C, controlled moisture, and specific microbial activity — that home compost bins don’t reliably provide. Some materials carry specific TUV Austria OK Compost HOME certification for home composting, but check the product’s certification mark to be sure.

How Long Does Bioplastic Take to Decompose?

Certified compostable bioplastics like PLA break down in 90–180 days in a certified industrial composting facility. In a landfill without oxygen, breakdown is much slower. PHA breaks down more broadly than PLA, including in soil and marine conditions. The disposal pathway determines the timeline, not the material alone.

Your Next Steps

You now have the vocabulary to cut through the noise. When you’re choosing packaging or single-use products, look for the BPI or TUV Austria certification mark, find your nearest industrial composting facility, and support companies whose claims are backed by independent standards.

We built Greenprint® around these principles: specific certifications, transparent sourcing, and products designed for a defined end-of-life pathway. Explore certified compostable products, learn about the future of bioplastics, or find out more about who we are.