Biodegradability vs. Compostability: What Food Businesses Need to Know

The Problem: Everyone Uses These Terms Incorrectly

Walk into any procurement meeting and you'll hear: "We need biodegradable packaging." Dig deeper and what they actually mean varies wildly-from "breaks down eventually" to "customers can compost it at home" to "meets EN 13432 certification."

This confusion isn't academic. It has real consequences:

• Regulatory compliance issues: Claiming "biodegradable" without specification may violate green claims guidelines

• Infrastructure incompatibility: Compostable packaging going to facilities that can't process it

• Customer frustration: Home compostable claims on industrially-compostable-only products

• Wasted R&D investment: Developing products for the wrong end-of-life pathway

As a paper converter working with food businesses since 1967, we've seen this confusion cost companies tens of thousands in reformulation, regulatory challenges, and damaged brand reputation.

This article provides the technical clarity you need to make informed decisions.

Section 1: Defining the Terms Properly

Biodegradability: The Broad Concept

Scientific Definition: The capability of a material to be broken down by living organisms (primarily bacteria and fungi) into natural substances like water, carbon dioxide, and biomass.

The Critical Variables:

1. Timeframe: "Eventually" is meaningless. Standards require specific timeframes (typically 6-12 months)

2. Conditions: Temperature, moisture, oxygen, microbial population all affect degradation rate

3. Completeness: Partial breakdown leaving microplastics or residues doesn't count

4. Environment: Landfill conditions differ drastically from soil, marine, or industrial composting

Relevant Standards:

• ISO 14855: Biodegradability under controlled composting conditions

• ASTM D5988: Soil biodegradation

• ISO 14851: Aquatic environment biodegradability

• EN 13432: Specific requirements for packaging recoverable through composting

Compostability: The Specific Subset

Scientific Definition: The ability to break down in a composting environment (industrial or home) within a specific timeframe, without leaving toxic residues, while supporting plant growth.

EN 13432 Requirements (European/UK Standard):

To claim "compostable," packaging must meet ALL four criteria:

1. Disintegration: After 12 weeks in industrial composting, <10% of material remains on a 2mm sieve

2. Biodegradation: At least 90% of organic material converts to CO2 within 6 months

3. Ecotoxicity: Resulting compost supports plant growth without toxic effects

4. Heavy metals: Content below specified thresholds (no contamination)

Critical Distinction - Industrial vs. Home Composting:

• Industrial composting: 58-70°C, controlled moisture, active turning, 12-16 weeks

• Home composting: 20-40°C, variable moisture, occasional turning, 6+ months

Materials certified for industrial composting may NOT break down in home composting conditions. This distinction causes massive consumer confusion.

Certification Bodies:

• TÜV Austria (OK compost, OK compost HOME)

• DIN CERTCO

• BPI (US, but recognized in UK)

• Seedling logo (European Bioplastics)

Section 2: How Paper Packaging Actually Degrades

Uncoated Paper: The Baseline

Pure cellulose fiber (uncoated, unprinted paper) is naturally biodegradable and compostable:

• Timeframe: 2-4 weeks in industrial composting, 6-12 weeks in home composting

• Conditions: Requires moisture and aerobic conditions

• Residues: None-complete conversion to CO2, water, and biomass

• Standards: Easily meets EN 13432 and home compost standards

The Catch: Uncoated paper has limited functional properties. Most food applications require moisture resistance, grease barriers, or release properties-which means coatings.

The Coating Problem

Every functional coating affects biodegradability. Here's the honest assessment:

Wax Coatings (Paraffin and PE Wax)

Composition:

• Paraffin wax: Petroleum-derived long-chain hydrocarbons

• PE wax: Low molecular weight polyethylene

Biodegradability:

• Timeframe: Paraffin: partial degradation over 12-24 months under ideal conditions; PE wax: minimal degradation over years

• Standards compliance: Neither meets EN 13432 requirements

• Environmental fate: Persistent in environment, does not support composting

Why We Still Use It: Excellent moisture barrier, food-safe, cost-effective, recyclable in many UK paper mills

Bio-Wax Alternatives (Soy, Beeswax, Plant-Based)

Composition: Triglycerides and fatty acids from renewable sources

Biodegradability:

• Timeframe: 8-16 weeks in industrial composting

• Standards compliance: Can achieve EN 13432 with proper formulation

• Environmental fate: Complete biodegradation to CO2 and water

Trade-offs:

• 25-40% cost premium over petroleum wax

• Lower melting point (stability issues in warm conditions)

• Variable performance with different paper substrates

• Still requires testing for each specific application

Real-World Example: We developed a bio-wax-coated butcher paper for a regional food retailer. EN 13432 testing confirmed industrial compostability, but the product failed in summer months due to wax softening. Solution required reformulation with higher-melting-point bio-wax blend, adding 15% to cost.

Silicone Release Coatings

Composition: Polydimethylsiloxane (PDMS) polymers

Biodegradability:

• Timeframe: Effectively non-biodegradable in relevant timeframes

• Standards compliance: Does NOT meet EN 13432

• Environmental fate: Persistent, chemically stable

Why We Use It: Essential for release applications (interleaving, baking papers) where no alternative matches performance

Disposal Strategy: Silicone-coated papers should target recycling, not composting

Aqueous/Dispersion Coatings

Composition: Water-based polymer dispersions (typically acrylic, styrene-acrylic, or modified starch)

Biodegradability:

• Timeframe: Highly variable-starch-based: 4-8 weeks; synthetic polymers: 6-24 months or more

• Standards compliance: Starch-based can meet EN 13432; synthetics typically don't

• Environmental fate: Depends entirely on polymer chemistry

Performance Limitations: Lower moisture and grease resistance than wax or silicone

Section 3: The Printing Ink Complication

Food-Safe Doesn't Mean Compostable

Most food-contact paper packaging is printed. Inks add another layer of complexity:

Water-Based Flexographic Inks (Our Standard):

• Components: Pigments, resins, water, additives

• Biodegradability: Pigments are typically not biodegradable; resins vary

• EN 13432 Impact: Can prevent certification if coverage is high or pigments contain heavy metals

• Best Practice: <5% surface coverage for compostability; use mineral pigments

UV-Curable Inks:

• Not suitable for compostable packaging

• Used only on non-food-contact surfaces where compostability isn't required

Section 4: Testing and Certification Process

What EN 13432 Testing Actually Involves

Achieving certified compostability isn't simple or cheap:

Testing Requirements:

1. Disintegration Test (12 weeks)

• Cost: £2,000-3,500

• Process: Industrial composting simulation with active monitoring

• Pass criteria: <10% residue on 2mm sieve

1. Biodegradation Test (6 months)

• Cost: £3,000-5,000

• Process: CO2 evolution measurement in controlled bioreactors

• Pass criteria: ≥90% conversion to CO2

1. Ecotoxicity Test

• Cost: £1,500-2,500

• Process: Plant growth trials with compost containing test material

• Pass criteria: ≥90% germination and biomass vs. control

1. Heavy Metals Analysis

• Cost: £500-1,000

• Process: Chemical analysis of material

• Pass criteria: Levels below EN 13432 limits

Total Cost for Full EN 13432 Certification: £7,000-12,000 per product configuration

Timeline: 9-12 months from submission to certification

Important: Certification is product-specific. Changing coating thickness, paper substrate, or printing coverage requires re-testing.

Section 5: UK Composting Infrastructure Reality

The Harsh Truth About Industrial Composting

UK Industrial Composting Capacity (2024):

• Approximately 250 industrial composting facilities

• Total capacity: ~3 million tonnes annually

• Primarily designed for food and garden waste

The Packaging Problem: Most facilities don't want certified compostable packaging:

1. Contamination Risk: Difficult to distinguish from non-compostable packaging

2. Processing Time: Packaging takes longer to break down than food waste

3. Quality Standards: Packaging residues affect compost quality certification

4. Economic Model: Food waste processing is profitable; packaging processing isn't

Collection System Gap:

• Most UK councils don't separate compostable packaging from food waste

• No clear consumer guidance on disposal

• Risk of contaminating recycling streams

Home Composting: Even More Complicated

Home Composting Reality:

• 4-5 million UK households have compost bins/heaps

• Average temperature: 20-40°C (vs. 58-70°C industrial)

• Variable moisture, irregular turning

• Timeframe: 6-24 months

Product Performance: Materials certified "OK compost HOME" (higher standard than EN 13432) may still take 12+ months to fully degrade in typical UK home composting conditions.

Section 6: Decision Framework for Food Businesses

When Biodegradable/Compostable Makes Sense

Strong Use Cases:

1. Event Catering and Food Service

• Controlled disposal environment

• Can contract with commercial composters

• Volume justifies collection logistics

• Examples: Festival serviceware, stadium food packaging

1. Agricultural Applications

• Direct soil incorporation possible

• Outdoor degradation acceptable

• Examples: Seed tapes, plant protection wraps

1. Niche Markets with Education Budget

• Premium positioning

• Customer base values sustainability

• Willing to invest in consumer education

• Examples: High-end delis, organic food brands

Poor Use Cases:

1. Mass-Market Retail

• Consumer confusion about disposal

• No collection infrastructure

• Cost premium difficult to justify

• Risk of contaminating recycling streams

1. Applications Requiring Extended Shelf Life

• Compostable materials can degrade during storage

• Moisture sensitivity issues

• Examples: Long-shelf-life dried goods

1. When Recycling Is Available

• Paper recycling is mature, effective, and economically viable

• Why chase compostability when recycling works?

Section 7: Alternatives to Consider

Recyclable Paper: The Pragmatic Default

For most food applications, optimizing for recyclability delivers better environmental outcomes than compostability:

Advantages:

• Established UK infrastructure (75% paper recycling rate)

• Economic value keeps materials in system

• Multiple recycling cycles possible

• Lower cost than compostable alternatives

Design Principles:

• Minimize coating coverage

• Use recyclability-compatible coatings (avoid silicone where possible)

• Water-based inks only

• No mixed materials (paper + plastic laminations)

Home-Washable and Reusable

For specific applications, washable paper (actually cellulose-based reusable material) offers interesting properties:

• Durability through 40-60 washing cycles

• Biodegradable after service life

• Premium positioning

• Examples: Reusable food wraps, storage solutions

Section 8: Regulatory and Claims Guidance

UK Green Claims Code

The CMA (Competition and Markets Authority) provides clear guidance on environmental claims:

To claim "biodegradable":

• Must specify timeframe and conditions

• Must have robust evidence

• Cannot imply rapid or complete degradation without proof

To claim "compostable":

• Must specify industrial or home composting

• Must state certification standard (EN 13432 or equivalent)

• Must be accurate about disposal infrastructure availability

Example of Compliant Claims: "Industrially compostable to EN 13432 standard. Not suitable for home composting." "Biodegradable in industrial composting conditions within 12 weeks."

Examples of Non-Compliant Claims: "Eco-friendly biodegradable packaging" "Compostable" (without specifying industrial or home) "Breaks down naturally"

Conclusion: Making the Right Choice

After decades of working with food businesses on packaging sustainability, our advice is:

1. Start with the End in Mind What disposal infrastructure is actually available to your customers? Design for that reality, not an ideal future.

2. Recyclability First for Most Applications Unless you have specific reason to pursue compostability (controlled disposal, regulatory requirement, strong market positioning), optimize for recyclability.

3. If Pursuing Compostability:

• Budget £10,000-15,000 for testing and certification

• Specify industrial vs. home clearly

• Have honest conversation with customers about disposal

• Don't assume infrastructure exists

4. Be Honest in Your Claims Vague green claims harm your brand and the industry. Specificity and evidence protect you.

5. Partner with Knowledgeable Converters Not all paper converters understand the nuances. Ask about testing experience, coating options, and infrastructure knowledge.

Related Articles

• Sustainable Paper Packaging: From Material Sourcing to End-of-Life - the pillar guide for this topic.

• The Hidden Carbon Footprint of Paper Packaging - Honest carbon analysis from pulp to delivery - and why UK manufacturing cuts emissions 40-55% vs imported alternatives.

• Beyond Recycling: Designing Paper Packaging for Circular Economy - Design for true circularity - UK EPR, MRF compatibility, contamination tolerance, and recyclability scoring.

• Wax Coatings and Release Agents: Performance vs. Environmental Responsibility - Compare wax and release coatings - paraffin, PE, soy wax, beeswax, silicone - performance, cost, sustainability trade-offs.