Compostable vs Biodegradable Packaging: What the Difference Actually Means

Compostable and biodegradable are the two most commonly conflated terms in sustainable packaging. They sound similar and are used interchangeably in supplier marketing — but they are not the same claim and they carry meaningfully different levels of evidence, regulation, and credibility.

The distinction has direct consequences for ecommerce brands. It determines what claims you can make to customers, what documentation you need to support those claims, and how your language holds up to regulatory scrutiny. Brands that have invested in sustainability positioning are particularly exposed when packaging language does not survive examination — the credibility gap between what the brand says and what the material actually does is one of the most common sources of greenwashing risk.

Consumer protection regulators have noticed. The ACCC in Australia has issued explicit guidance on misleading environmental claims, citing vague biodegradable language as a known problem area. The UK CMA's Green Claims Code requires that claims be accurate, clear, and not misleading. The EU's proposed Green Claims Directive would require pre-verification of many sustainability claims before they are used in marketing. Across all three jurisdictions, the direction of travel is more scrutiny, not less.

The table below summarises the key packaging claim categories — what each means, whether it is regulated, and what to ask suppliers.

Compostable packaging is designed to break down into non-toxic components under composting conditions, within a defined timeframe, according to a recognised standard. Every element of that definition matters: non-toxic outputs (not just fragmentation into smaller plastic pieces); specific conditions (not any environment); defined timeframe (not eventually); recognised standard (not a self-declared supplier claim).

The recognised standards globally are: AS5810 (home compostable) and AS4736 (industrial compostable) in Australia, certified by ABAP; EN 13432 and OK compost HOME in Europe, certified by TÜV Austria and DIN CERTCO; and ASTM D6400 and D6868 in North America, certified by BPI. Without certification to one of these standards, a compostable claim is not independently verified.

A further critical layer: home compostable and industrial compostable are meaningfully different. Home compostable packaging breaks down in a domestic compost bin without industrial processing. Industrial compostable packaging requires managed facility conditions — typically temperatures above 55°C — that a domestic bin cannot replicate. A compostable claim without specifying which type is incomplete and potentially misleading. For a detailed explanation of this distinction, see the Home Compostable vs Industrial Compostable packaging guide.

Biodegradable describes any material that will eventually break down through biological processes. Technically, this includes conventional plastic — it just takes centuries and fragments into microplastics. The term has no regulated definition in most markets, no required conditions, no standard timeframe, and no testing requirement. Almost any material can be marketed as biodegradable without that claim being technically false.

For ecommerce brands, using 'biodegradable' as a primary claim creates two problems. The first is commercial: it tells customers almost nothing useful about what to do with the packaging or what environmental benefit it actually delivers. 'Biodegradable — pop in your compost bin' is a clear instruction. 'Biodegradable' alone is not. The second is regulatory: consumer protection authorities — including the ACCC in Australia and the CMA in the UK — are increasingly treating vague biodegradable claims as potentially misleading when used to imply environmental benefits that are not specific or evidenced.

This does not mean biodegradable is always dishonest. Some suppliers use it to describe materials with defined breakdown pathways under realistic conditions. But for ecommerce brands wanting credibility, biodegradable as a standalone claim is not sufficient. A defensible approach is to specify what the material is, what conditions it breaks down under, what timeframe applies, and what the customer should do with it. If those specifics point to a recognised compostable standard, lead with compostable and cite the certification.

Oxo-degradable packaging is conventional plastic with chemical additives designed to cause it to fragment into smaller pieces over time when exposed to UV light, oxygen, or heat. The problem: the resulting material is still plastic, just in smaller pieces — microplastics — that enter soil and water systems more easily than intact plastic.

The scientific and regulatory consensus has hardened significantly. The European Union banned oxo-degradable plastic packaging in 2021 under the Single-Use Plastics Directive. ABAP in Australia does not certify oxo-degradable materials as compostable. The Ellen MacArthur Foundation has described oxo-degradable claims as misleading. If a supplier uses oxo-degradable language as eco-friendly positioning, treat that as a red flag and probe further before committing.

The practical test is straightforward: ask for the specific standard, the certifying body, a certificate number, and an expiry date. If they can provide all four, the claim is on solid ground. If they respond with marketing language, refer you to a brochure, or cannot name a certifying body, the claim is not independently supported.

Requesting samples before a production run is a further practical step. Samples allow you to test seal strength, waterproofing, and how the packaging handles your actual products. A supplier confident in their product should provide samples readily. Zero Pack provides certification documentation and samples on request as part of the quoting process. To begin a quote for custom branded compostable packaging, use the custom compostable mailers enquiry page.