As demand for sustainable packaging grows, compostable labels are gaining attention as an eco-friendly alternative. But what makes a label compostable, and how do you ensure it aligns with your packaging and environmental goals?
What Makes a Label Compostable?
A compostable label must break down into non-toxic components-carbon dioxide, water, and biomass—within a specific time frame under composting conditions. This process is governed by standards like EN 13432 (EU) and ASTM D6400 (US), which require:
- Complete disintegration within 12 weeks in industrial composting environments
- Biodegradation of at least 90% within six months
- No toxic residue that affects compost quality
To meet these criteria, every component of the label—face stock, adhesive, and ink—must be compostable.
Key Components to Consider
Choosing the right compostable label means understanding the materials involved:
- Face Materials: Often made from PLA (polylactic acid) or cellulose, these are plant-based and biodegradable. Look for certifications that confirm compostability, such as TÜV OK Compost.
- Adhesives: Traditional glues may contain synthetic compounds that leave residue. Compostable adhesives use natural rubber or water-based formulas approved for industrial composting.
- Inks: Soy-based and water-based inks are preferred for compostable labels. Avoid heavy metals and synthetic stabilisers that could interfere with the composting process.
Industrial vs. Home Composting
Most compostable labels are designed for industrial composting, which requires high heat and controlled conditions. Labels that are home compostable must degrade at lower temperatures and over a longer period. If your packaging targets consumers who compost at home, verify that the label has certifications like OK Compost Home.
Challenges in Real-World Use
Even labels that meet compostability standards on paper can struggle in practice.
- Durability: Compostable materials are designed to break down, but that can become a problem during distribution. Exposure to moisture, humidity, or rough handling may cause labels to peel, smudge, or degrade too soon. This makes them less suitable for long supply chains or refrigerated storage without rigorous testing.
- Application Compatibility: Many compostable adhesives have lower tack or slower set times compared to conventional options. This can lead to poor adhesion on curved or slick surfaces and can disrupt production lines running at high speeds. Some compostable face materials are also thinner or more fragile, making them prone to tearing during automatic application.
- End-of-Life Confusion: Compostable labels work best when applied to fully compostable packaging. If the label is compostable but the container is not, or vice versa, the mixed materials can create problems in waste sorting facilities. Consumers may also misunderstand disposal instructions, leading to contamination in compost or recycling streams. Clear guidance on packaging helps reduce these risks.
How to Choose the Right Compostable Label
To make the right decision:
- Evaluate Your Packaging: The entire package should be compostable if you’re using compostable labels. Mixing materials limits effectiveness.
- Consider Label Lifespan: Choose labels that remain intact during transport and storage but break down as required during composting.
- Look for Third-Party Certification: Trusted certifications remove guesswork and verify environmental claims.
- Test Before Scaling: Trial runs can reveal issues with adhesion, print clarity, or compatibility with your labelling system.
Final Thoughts
Compostable labels are a step toward sustainable packaging, but they require thoughtful selection and proper end-of-life handling. By understanding the science and choosing components that align with both your product and your values, you can ensure your labels support true environmental responsibility.