5 Types Of Biodegradable Plastics In 2025

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Curious about biodegradable plastics?

You’ve probably heard about them as “the green alternative” to regular plastic. But what are they really? Are they better for the planet? And what types actually exist?

Plastic pollution is a huge problem, and biodegradable plastics seem like a perfect fix. But the reality is more complicated. Different types of biodegradable plastics work differently, and some aren’t as eco-friendly as they sound.

In this guide, we’ll look at 5 common types of biodegradable plastics – plus compostable plastics – and what makes each unique. By the end, you’ll know how to spot them and what to expect.

Let’s break it down simply and clearly.

The 5 main types of biodegradable plastics (+ compostable ones)

A summary table of the different types of biodegradable plastics, their sources, how they break down, and examples:

Type	Source material	How it breaks down	Examples
Bio-based plastics	Plants (corn, sugarcane, starch, etc.)	Microorganisms decompose them under right conditions	PLA, PHA, Bio-PE
Synthetic vioplastics	Fossil fuels + modified polymers	Designed to degrade, but often under specific conditions	Bio-PET, PBS, bio-PP
Oxo-degradable plastics	Traditional plastics + additives	Oxidation (light + oxygen) breaks them into fragments	PE with oxo-additives
Photo-biodegradable	Traditional plastics + UV-reactive agents	UV light triggers breakdown into smaller pieces	PE with photo-additives
Hydro-biodegradable	Starch, cellulose	Water triggers hydrolysis, then microbes digest	Starch-based materials, cellulose blends
UV light triggers a breakdown into smaller pieces	Starch, proteins, algae, cellulose	Fully break down in industrial composting facilities	PLA blends, potato starch, soy protein resins

1. Bio-based plastics:

What are they:

These plastics come from natural sources like plants, algae, or even bacteria. Imagine making plastic out of corn, sugarcane, or potatoes instead of oil. Sometimes, bio-based plastics are 100% plant-based; other times, they mix natural and synthetic materials.

Challenges: 

Not all bio-based plastics actually break down easily. Some behave more like regular plastic. Not all bio-based plastics are entirely renewable, raising questions about their overall eco-friendliness. 

Examples:

Examples of renewable carbon resources include corn, potatoes, rice, soy, sugarcane, wheat, and vegetable oil. Usually, most biobased plastic is just partially biobased. A few more include:

• Polylactic Acid (PLA) – often used in disposable cups and packaging
• Polyhydroxyalkanoates (PHA)
• Bio-based polyethylene

2. Synthetic bioplastics:

What are they:

These are man-made plastics designed to act like regular plastic but with better degradation properties. They’re made in labs using synthetic polymers but sometimes include bio-based ingredients.

Challenges: 

Issues include sustainability concerns due to energy-intensive production, a lack of standardized definitions, and vagueness surrounding their true environmental impact. 

Examples:

• Polybutylene Succinate (PBS)
• Bio-based versions of polyethylene terephthalate (PET)
• Specific bio-based polypropylenes

3. Oxo-degradable plastics:

What are they:

These look like normal plastic but have additives that help them break down faster when exposed to air and sunlight. They fragment into smaller pieces, but those pieces don’t always disappear. (1, 2)

Challenges: 

Oxo-degradable plastics, though intended to break down quickly face challenges such as microplastic issues, variable degradation effectiveness, and the lack of standardized specifications. The additives used can raise environmental concerns, too.

Examples:

• Polyethylene with oxo-additives – often plastic bags

4. Photo-biodegradable plastics:

What are they:

Photo-biodegradable plastics react to ultraviolet (UV) light, initiating a quicker breakdown process. Typically, they go through initial stage of oxo-degradation to make them susceptible to the following biodegradation under UV light exposure. 

Challenges: 

Photo-biodegradable plastics, which respond to UV light, face challenges due to their restricted use in specific environments, dependence on oxo-degradation, ongoing research requirements, and potential issues in waste management systems.

Examples:

• Some formulations of polyethylene with photo-sensitive additives

5. Hydro-biodegradable plastics:

5. Hydro-biodegradable Plastics

What are they:
Made mainly from plant starches (like corn or potatoes), these plastics break down when water and microbes start “eating” them through a process called hydrolysis (think of water slowly dissolving the plastic).

Challenges: 

Highly dependent on disposal conditions for effective degradation; they need moist conditions to break down and don’t work well in dry environments. The decomposition rates vary, and production is resource-intensive.

Examples:

• Starch-based packing peanuts or films
• Specific cellulose-based materials

There’s another material worth mentioning, and that’s it…

Bonus – Compostable plastics:

What are they:

Compostable plastics require specific composting conditions, involving aerobic (oxygen-dependent) environments. They break down into carbon dioxide, water, inorganic compounds, and biomass without leaving harmful residues. 

Proper disposal in commercial composting facilities is crucial, as these plastics won’t break down on their own in landfills, as litter, or in marine environments. (1, 2, 3) They need specific conditions, which can be generally found only at commercial composting facilities. The different criteria in different countries are:

• European Standards: Compostable plastics must break down under industrial composting conditions in less than 12 weeks. 
• Australian Standards: Compostable plastics should disintegrate within 12 weeks. Complete biodegradation within six months, converting 90% or more to CO2, water, and biomass. 
• US Standards: No more than 10% of the original dry weight should remain after 84 days. 90% of the organic carbon in the test materials must convert to carbon dioxide within 180 days.

Challenges: 

Compostable plastics, requiring specific disposal conditions, face challenges such as limited infrastructure for proper disposal, potential misuse and contamination issues, resource intensity in production, and varying degradation timeframes across regions.

Examples:

• Resins made from potato starch
• Soybean protein
• Cellulose

Quick recap: what to remember

• Not all biodegradable plastics are created equal. Most need special conditions to break down, and won’t decompose in your backyard or a landfill.
• Bio-based doesn’t always mean biodegradable. A plastic can be plant-based but still hang around for years. (1)
• Oxo- and photo-degradable plastics can create microplastics, which are harmful to the environment.
• Compostable ≠ biodegradable. Composting typically takes place in aerobic environments (requires oxygen), while biodegradation may take place in anaerobic environments (doesn’t require oxygen). (1) 
• Compostable plastics are great if you have access to industrial composting. Otherwise, they won’t break down properly.
• Where you live matters. Composting and recycling rules are different everywhere, so always check what your local waste system accepts.

How to be smarter about using bioplastics:

• Don’t mix biodegradable plastics with regular recycling – it can contaminate the process.
• Choose reusable over single-use whenever possible.
• Look for clear labels like “home compostable” or certifications.
• Find out if your local compost or recycling system accepts biodegradable or compostable plastics.

FAQ — Quick answers to your questions

Are biodegradable plastics truly better for the planet?
They can be, but only if disposed of correctly. In landfills or the ocean, many still stick around for years. A 2019 study revealed that biodegradable plastic bags remained intact after three years, whether submerged in the sea or buried underground. Check a quick video that summarizes the study here:

Biodegradable bags can hold a full load of shopping after 3 years in the environment

How does plastic biodegrade?
Most biodegradable plastics, derived from traditional petrochemicals, contain additives for faster breakdown under light, oxygen, moisture, and heat. Microorganisms like bacteria accelerate decay, resulting in decomposition into water, carbon dioxide, methane, and biomass. (1)

Do biodegradable plastics always come from plants?
Nope. Some are made from petroleum but engineered to degrade faster.

Should I switch to biodegradable bags?
Reusable bags are usually the best eco choice. If you use disposables, pick certified compostable bags and dispose of them properly.

Can biodegradable plastics break down in landfills? 
No, most landfills limit biodegradation due to low oxygen and moisture levels. (1)

Biodegradable vs. compostable: which is better? 
Composting is generally faster, but it requires specific conditions. Home compostable alternatives may be the best choice, especially if you have a home compost.

Are biodegradable plastics always compostable? 
No, as “biodegradable” and “compostable” differ. Compostability depends on specific conditions and standards, and not all compostable plastics suit all industrial or home composting facilities. 

Are compostable plastics suitable for all industrial composting operations?
It depends. Some standards demand complete biodegradation in 180 days, conflicting with industrial composters that finish in 60-90 days.

Are all compostable plastics suitable for home composting? 
If labeled “home compostable”, usually yes. However, many compostable plastics need higher temperatures than are found in industrial facilities, and not in backyard composting.

Final thoughts

Biodegradable plastics sound like a great solution, but they’re not a magic fix.

Some break down only in specific conditions (like industrial composting), others can leave behind microplastics, and not everything labeled “bio-based” will biodegrade.

Understanding the differences – like how compostable ≠ biodegradable, and plant-based ≠ harmless – is key to making smarter, more sustainable choices. And when in doubt, the most eco-friendly move is still to reduce and reuse whenever you can.

Let’s stay curious, ask the right questions, and keep aiming for better. 🌱

Let me know in the comments below if you have any questions, or what your thoughts are on all this!