“Compostable” gets printed on a lot of packaging these days. But the word alone doesn't tell you much and at EcoSafe, we think it should mean something real. 

Behind every genuinely compostable product are three separate scientific hurdles it must clear: it must physically fall apart, its carbon must be fully consumed by microbes, and the compost left behind must be safe for soil and plants.

These are known as the three benchmarks of compostability: disintegration, biodegradation, and eco-toxicity. Together they're what separate a product that's truly compostable from one that just claims to be.

Here's what each one means, and why a product must pass all three (not just one) to earn the label.

Benchmark 1: Disintegration 
The question it answers: Does the product physically break apart?

For a product to disintegrate properly, it needs to lose its structure and break into pieces small enough to disappear into finished compost, generally around 2 mm in size. By the end, it should be visually indistinguishable from the compost around it.

Here's the catch: disintegration on its own proves nothing about whether the material has broken down at the molecular level. A product can shatter into tiny pieces while its polymer chains stay fully intact which is exactly how conventional and "oxo-degradable" plastics end up creating microplastics. Falling apart is necessary. It's just not enough on its own.

Benchmark 2: Biodegradation 
The question it answers: Is the carbon actually consumed?

This is the real biological finish line. Biodegradation means microorganisms metabolize the material's carbon and convert it into carbon dioxide, water, and new microbial biomass, proof that it's genuinely rejoining the natural carbon cycle instead of just breaking into smaller, still-persistent fragments. 

To pass, a product generally needs to demonstrate conversion of its organic carbon into CO2, measured against a known reference material like cellulose. Labs verify this through respirometry, capturing and measuring the CO2 that microbes give off as they consume the material.

Here's the catch: biodegradation confirms the carbon is gone, but it says nothing about what else might be left behind in the compost which brings us to the third benchmark.

Benchmark 3: Eco-Toxicity and Compost Safety 
The question it answers: Is what's left behind actually safe? 

Composting exists to return nutrients to soil, so the final compost needs to support plant life, not suppress it. To pass this benchmark, compost made from the material generally needs to support seed germination and plant biomass consistent with a control batch without it. At the same time, regulated heavy metals such as lead, cadmium, mercury, chromium need to stay well under regulatory limits, commonly below 50% of the maximum allowed.

This is also where PFAS scrutiny comes in. A product that disintegrates and biodegrades perfectly but leaves behind heavy metals or forever chemicals has defeated the entire purpose of composting in the first place.

Why a Product Needs to Pass All Three and Not Just One

Each benchmark closes a loophole the others can't catch on their own:

Disintegration without biodegradation = microplastics. The product disappears but persists in the environment as fragments.

 Biodegradation without proper disintegration = operational headaches and incomplete breakdown within a facility's real-world timelines.

Disintegration and biodegradation without eco-toxicity screening = risks generation of contaminated compost that can suppress plant growth or introduce heavy metals into soil.

Only a product that clears all three (falls apart, gets consumed, and does not harm compost) has genuinely composted. That's the entire reason certification exists: to confirm a product passes the full battery of tests, not just one convincing demonstration.

Where These Standards Come From

These aren't informal guidelines; they're written into consensus standard specifications. In North America, that's ASTM D6400 (for compostable plastics) and ASTM D6868 (for plastic coatings on paper and fiber products), both of which require all three benchmarks and are consistent with international ISO methods and Europe's EN 13432.

And critically, certification confirms performance of the finished product as it's actually sold, not just the raw resin. Inks, adhesives, coatings, laminations, product shape, and wall thickness all affect how a product performs. A resin that passes on its own can fail once it's printed, coated, or built into a thicker item, which is why two products made from the same bioplastic can have genuinely different real-world outcomes.

How EcoSafe Backs Up the Claim

This is exactly why certification matters to us. Every EcoSafe compostable product is built to meet BPI Certification against ASTM D6400, and performance is demonstrated/documented in accredited labs, under simulated composting conditions, with third-party review of both formulation and performance. It's also why we look to CMA approval, who tests in all three commercial composting processes (we pass all three). With both verifications, we go through strict PFAS testing standards as they are among the most stringent in the industry.

For us, "compostable" isn't a word we put on a bag, it's a claim we can back up with the science behind it, every time. Want to learn more? BPI has a fantastic blog about what biodegradable really means.

Have questions about how our products are certified, or want to see the documentation behind a specific product line? Reach out to our sustainability team, we're happy to walk through it.