Are All Dog Poop Bags Biodegradable? The Truth Behind the Label

barkridges
Nov 27
4 min read

Updated: 4 hours ago

The short answer is no. Not all dog poop bags are biodegradable. In fact, many bags marketed as "eco-friendly" or "degradable" are made from standard petroleum-based plastics mixed with additives that simply break the bag down into smaller microplastics, rather than returning it to nature.

If you are a dog owner trying to reduce your pawprint, understanding the difference between biodegradable, compostable, and oxo-degradable is critical to avoiding greenwashing.

Google shopping search result for "biodegradable dog poop bags"

The 3 Types of Dog Poop Bags (And Which One is Actually Green)

When you shop for poop bags, you will typically encounter three confusing labels. Here is how to decode them:

1. Biodegradable (The Gray Area)

Technically, "biodegradable" just means a material can be broken down by biological processes (bacteria or fungi). However, there is no time limit on this. A plastic bag that takes 500 years to break down can technically be called "biodegradable."

The Trap: Without a specific certification, this term is often used for marketing without guaranteeing the bag will decompose quickly or safely.

2. Compostable (The Gold Standard)

Compostable bags are a specific subset of biodegradable bags. To be labeled "compostable," the bag must break down into non-toxic organic matter (CO2, water, and biomass) within a specific timeframe under the right conditions.

The Critical Distinction: Home vs. Industrial

Not all "compostable" bags are created equal. The key difference is the required temperature for breakdown:

Industrial Compostable: Requires high, consistent heat (typically 55ºC to 71ºC or 131ºF to 160ºF), controlled moisture, and specialized turning equipment. They achieve 90% degradation in 180 days. Most waste facilities in the UK do not accept pet waste, making this certification often irrelevant to dog owners.
Home Compostable: Designed to break down at lower, ambient, and inconsistent temperatures (around 20ºC to 30ºC) found in a garden compost bin. This process is slower, requiring up to 12 months for full degradation. This is the only compostable certification that matters for the most UK dog owner.

3. Oxo-Degradable (The "Greenwashing" Villain)

These are often traditional plastics with chemical additives (heavy metals) that make the plastic brittle. They fragment into tiny pieces when exposed to sunlight or heat.

The Problem: They do not biodegrade; they just become invisible microplastics that pollute the soil and water. The EU has largely moved to ban these plastics due to their environmental harm.

The "Dirty Truth" About Landfills

This is the most important factor most dog owners miss: A biodegradable bag cannot biodegrade in a landfill.

Landfills are designed to be "anaerobic" environments (lacking oxygen). They are tightly compacted to prevent decomposition.

The Reality: If you throw a certified compostable cornstarch bag into the trash, and it goes to a landfill, it will "mummify" just like a standard plastic bag.
The Risk: Worse, if it does manage to break down in an anaerobic landfill, it may release methane, a greenhouse gas 25x more potent than CO2.

Key Takeaway: Buying an expensive compostable bag is only half the battle. How you dispose of it matters more.

How to Spot a Fake: Certifications to Trust

Don't trust the words "Earth Friendly" written in green font. Flip the box over and look for these specific third-party certifications. If you don't see them, it's likely greenwashing.

Certification	Type of Composting	What It Means
TÜV AUSTRIA (OK Compost HOME)	Home (Low Heat)	The Gold Standard. Verifies the bag will break down safely in your backyard compost bin within 12 months. Look for this one!
EN 13432	Industrial (High Heat)	The strict European Union standard for industrial composting.
ASTM D6400	Industrial (High Heat)	The U.S. standard for industrial composting.
BPI Certified	Industrial (High Heat)	A trusted North American mark for products meeting the ASTM D6400 standard.

The UK Context: Why "Home Compostable" Wins in the UK

If you live in the UK, the rules of the game are slightly different. The majority of general waste—including the contents of public dog waste bins—does not go to landfill. It goes to Energy-from-Waste (incineration) plants.

In this scenario, Certified Home Compostable bags are scientifically superior to Recycled Plastic bags for two reasons:

Renewable Carbon vs. Fossil Carbon: When you burn a plastic bag (even a recycled one), you are releasing "fossil carbon" that was trapped underground for millions of years, actively contributing to climate change. When you burn a plant-based compostable bag (cornstarch), you are releasing "biogenic carbon" (carbon recently absorbed by the plants), which is considered far closer to carbon neutral in the waste cycle.
Toxicity: Plant-based bags burn cleaner, releasing fewer toxic byproducts than polyethylene plastics.

The Verdict: What Should You Buy?

The Winner (Best for UK & Composting): Certified Home Compostable

Why: They are the safest "all-rounder." If you compost at home, they work. If you bin them in the UK, they burn cleaner than plastic. If you accidentally drop one, it won't leave microplastics.
Buy: Adios Plastic or Barkridges®. Both are certified TÜV Home Compostable and 100% plastic-free.

The Runner Up (Budget Friendly): Recycled Plastic

Why: If you cannot afford compostable bags, these are the next best thing. They give a second life to waste plastic rather than creating new "virgin" plastic.
Buy: Earth Rated (Green Box) or Beco (Recycled Range). Note: Earth Rated bags are not biodegradable; they are 65% post-consumer recycled plastic. Beco’s recycled range is 100% recycled plastic.

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Frequently Asked Questions

Can I put compostable dog bags in my council's green bin? Rarely. Most local authority composting facilities strictly ban pet waste because it contains harmful pathogens (like E. coli) that standard composting cycles may not kill. Always check with your local council or authority first.
Are cornstarch bags better than plastic? Yes, but only if composted. Cornstarch is a renewable resource, whereas plastic is made from fossil fuels. However, producing cornstarch still requires land, water, and energy.
What happens if I leave a biodegradable bag in the woods? Please don't! Even certified bags need specific conditions (heat/humidity) to break down. In the woods, they can last for years, smothering plants and confusing wildlife who might try to eat them. Always "Leave No Trace."