Author: Ellis Fowler

Choosing the right adhesive has always been about balancing performance, efficiency, and cost. Under the EU Packaging and Packaging Waste Regulation (PPWR), there’s now a fourth dimension to consider and that is end-of-life alignment.

It is important to remember that not all biodegradable or compostable adhesives behave the same way and not every formulation suits every packaging type. To stay compliant and operationally efficient, converters must match adhesive chemistry to both substrate and intended recovery route.

Under EN 13432, all major components of compostable packaging must biodegrade and disintegrate under controlled industrial composting conditions. For adhesives, this means maintaining high performance during use and then safely breaking down into carbon dioxide, water, and humus when composted, with no microplastics or eco-toxicity.

However, packaging formats vary widely in temperature, bonding area, and load stress. A single adhesive type rarely fits all. Understanding the differences can save converters from costly trial-and-error and compliance setbacks.

Matching adhesives to packaging formats

Selecting the right compostable adhesive depends on both the packaging format and its intended end-of-life pathway. Each type of packaging presents unique challenges for converters, from production efficiency to bond strength and recyclability.

Fibre-based trays and wraps

Compostable trays and wraps used for produce or food service packaging demand adhesives that offer both strength and precision. These applications typically involve bonding coated or uncoated paperboard, which can vary in porosity and surface texture. A suitable biodegradable hot melt must provide a strong initial tack to hold the structure in place immediately, especially on fast-moving lines, while maintaining flexibility as the material cools.

Tecbond biodegradable adhesives achieve this by setting quickly and cleanly, preventing stringing or residue build-up on equipment. This clean-running performance not only reduces downtime but also ensures a smooth finish for high-volume production. When disposed of correctly, these adhesives then break down fully under industrial composting conditions, aligning with EN 13432 standards for biodegradation and disintegration.

Corrugated outers and display units

Outer packaging and lightweight display units must maintain integrity through handling, storage, and transport. These applications often require a balance between high bond strength and process efficiency. Compostable adhesives designed for corrugated materials provide the strong adhesion needed to withstand compression and vibration without delamination. The key is selecting a formulation proven to bond effectively with kraft paper and board substrates while maintaining compostability at end of life. Using a compatible hot melt also prevents contamination of recycling or composting streams, helping converters meet sustainability and compliance targets simultaneously.

Paper labels and fruit stickers

Labels and stickers are among the few packaging components explicitly required to be compostable under the PPWR. Adhesives used in these applications must hold securely to delicate or uneven surfaces like fruit skins or paper wraps, while also meeting strict compostability criteria. Certified biodegradable hot melts tested to EN 13432 or ASTM D6400 provide both reliable adhesion and verified environmental performance. By selecting these adhesives, converters can ensure their labels meet legal standards and customer expectations, avoiding the compliance risks associated with non-compostable alternatives.

Key takeaways for converters

• Check certification: Look for EN 13432 or ASTM D6400 compliance and supplier documentation.
• Align to substrate and recovery route: The right adhesive depends on whether the pack is destined for composting or recycling.
• Test performance: Evaluate open time, viscosity, and bond strength to ensure process compatibility.
• Plan early: Certification and customer approval cycles take time, integrating compliant adhesives now prevents disruption later.

Selecting the right compostable adhesive is not only about meeting regulation, but also about designing packaging that performs as well at end-of-life as it does on the line.

By mid-2027, the EU’s Packaging and Packaging Waste Regulation (PPWR) will reshape the European packaging landscape. Among its most significant changes is the requirement for certain packaging formats to be compostable, forcing converters and brand owners to reassess the materials, including adhesives, they use every day.

What the 2027 compostability mandate means

The PPWR will make compostability mandatory for specific packaging categories that are contaminated with organic waste or intended to be processed through bio-waste collection systems. This includes:

• Tea bags and coffee pods or capsules
• Sticky labels on fruit and vegetables
• Lightweight plastic carrier bags
• Certain food-contact packaging, such as fibre-based trays, wraps, and films used for fresh produce or ready meals

For converters working with these formats, this means one thing and that is every component, from films and coatings to inks and adhesives, must be proven compostable in accordance with EN 13432 or ASTM D6400.

The adhesive connection

Adhesives may account for a small proportion of total packaging weight, but under EN 13432’s “1% rule”, any component exceeding 1% of a pack’s dry weight must be individually certified as compostable. Even below that, adhesives count towards the total 5% cap on non-compostable content.

In practice, this means that using a standard hot melt adhesive could jeopardise a pack’s compostability claim, even if the rest of the materials comply. For converters, it is not enough to specify a biodegradable substrate; the adhesive must match the pack’s intended end-of-life.

What converters should be doing now

The 2027 deadline may seem distant, but certification takes time, particularly for complex or multi-material packs. Converters should begin preparing by:

1. Auditing existing adhesive use: Identify which products are used across compostable or bio-based packs and determine whether they hold recognised certification (EN 13432 or ASTM D6400).
2. Engaging with suppliers: Request compliance documentation and evidence of biodegradability and disintegration testing.
3. Testing for compatibility: Evaluate whether certified biodegradable adhesives deliver the required performance for sealing, tray assembly, or labelling without affecting throughput or bond strength.
4. Designing for recovery: Ensure all components align to the same recovery route — composting, recycling, or mechanical separation.

Converters adopting certified biodegradable hot melts, such as Power Adhesives’ Tecbond range, can move faster and with greater confidence towards compliance. These adhesives are engineered to maintain performance through use, then safely biodegrade under industrial composting conditions without leaving microplastics behind.

The cost of inaction

Failing to prepare could result in non-compliant packaging that cannot legally be placed on the EU market after 2027. Beyond fines or redesign costs, there is also the reputational risk: brands caught out by “greenwashing” or invalid claims face public and commercial scrutiny.

As more retailers and manufacturers align with PPWR timelines, converters that have already tested, validated, and certified their packaging will be at a competitive advantage. Adhesives are not just a technical consideration, they are a compliance-critical material in the journey toward circular packaging. Now is the time to evaluate, test, and prepare because when 2027 arrives, only packaging proven to be compostable will make the cut.

Across packaging and manufacturing, sustainability choices are increasingly scrutinised. Adhesives are often a small proportion of a pack by weight, yet they can influence recyclability and compostability outcomes. For converters and brands seeking credible, demonstrable improvements, understanding what “biodegradable” means in practice is essential.

Power Adhesives created the world’s first ever biodegradable hot melt range, and this post explains the technical basis behind certified compostable adhesives and the specific attributes customers can verify.

What certification actually proves

The most important tests for compostable materials are independent certification standards. Two widely recognised standards are EN 13432 in Europe and ASTM D6400 in the United States.

EN 13432 sets laboratory criteria for industrial compostability. Key elements include biodegradation (a high proportion of the material must be converted to carbon dioxide under controlled composting conditions within a defined timeframe), disintegration (no visible fragments above a small size after a set period) and ecotoxicity (the compost produced must not inhibit plant growth). ASTM D6400 uses similar test principles tailored to US industrial composting conditions.

Our Tecbond biodegradable adhesives are certified to EN 13432 and ASTM D6400. Those certifications are the primary independent evidence that these adhesives meet the specified compostability test protocols under controlled industrial conditions.

What certified biodegradable adhesives are designed to do

A product certified to EN 13432 or ASTM D6400 has been independently tested against the lab methods in those standards. For converters this means:

• The adhesive has undergone biodegradation and disintegration testing under controlled composting conditions.
• The certification process includes checks for harmful residues and ecotoxicity impacts on plant growth.
• Certification is granted by an accredited third-party following laboratory assessment and, where required, ongoing surveillance.

It is important to be clear about limits. These standards apply to industrial composting environments. They do not mean that a product will rapidly biodegrade in a backyard compost heap or in all natural environments. Certification verifies behaviour under defined, managed conditions typical of industrial composting facilities.

Performance in use and storage

Customers commonly ask whether biodegradable adhesives perform like conventional hot melts during production and whether they will remain stable in storage. Power Adhesives publishes a recommended shelf life of 24 months (from date of manufacture) for its biodegradable shaped adhesives when stored correctly away from direct sunlight, heat and moisture. That shelf-life statement is a practical specification customers can rely on for planning and logistics.

Certified biodegradable adhesives are intended to provide predictable application behaviour during their service life and then meet compostability criteria at end of life when processed under industrial composting conditions. Where customers require detailed performance metrics (open time, set speed, bond strength on specific substrates), technical data sheets and application trials remain the appropriate way to confirm suitability for a given production line.

Where biodegradable adhesives fit in a packaging strategy

From a compliance perspective, adhesives are increasingly relevant. For packs intended for industrial composting, any component that must be tested as part of a compostability claim should be backed by appropriate certification and documentation. Certified biodegradable adhesives provide a traceable route to support those claims.

That said, using a certified compostable adhesive is only one part of a broader material strategy. Converters should ensure the entire pack design, including substrates, inks and coatings, aligns with the chosen end-of-life pathway and that collection and processing routes exist for industrial composting in the target market.

Practical next steps for converters

If you are evaluating biodegradable adhesives for your line:

• Request certification documents (EN 13432, ASTM D6400) and technical data sheets from the supplier.
• Run application trials on your substrates and equipment to confirm bond performance and handling.
• Confirm recommended storage conditions and shelf life for ordering and inventory planning.
• Consider the end-of-life pathway for the full pack and whether industrial composting infrastructure exists where your product will be collected.

Evidence-led innovation

The role of adhesives in sustainable packaging is becoming more visible because independent standards exist to verify compostability. Power Adhesives’ published certifications for its Tecbond biodegradable range give converters a starting point to assess whether a certified adhesive can form part of a compliant packaging solution. For technical assurance, converters should combine certification review with practical trials and documentation checks to ensure performance and compliance on their specific production lines.

The Packaging and Packaging Waste Regulation (PPWR) is raising the bar for compostable packaging across Europe. Among its technical requirements, one small but critical detail stands out for adhesives. This is the “1% rule” as defined in EN 13432. This rule may sound like a minor detail, but for converters aiming to certify compostable packaging, it can make the difference between a valid claim and a rejected application.

What the 1% rule means

Under EN 13432, any single packaging component that makes up more than 1% of the pack’s dry weight must be individually proven compostable. Adhesives are included in this definition.

That means if an adhesive contributes more than 1% of the total dry weight, it cannot simply be ignored in testing. It must meet the same standards of biodegradation, disintegration, and safety as the rest of the pack.

The rule also states that the sum of all non-compostable components in a pack cannot exceed 5% of its weight. This means adhesives below the 1% threshold still matter. If combined with other non-compostable elements (such as inks, coatings, or barriers), they could push a pack over the 5% allowance and invalidate the claim.

Why adhesives often cross the threshold

Although adhesives are often perceived as negligible, their contribution to overall pack weight is not always minor. Industry data shows that adhesives typically account for less than 2% of total packaging weight, but in more complex formats, such as laminated cartons, wraparound trays, or fibre-based packs with plastic windows, that figure can rise much higher. In fact, some reports note that in certain applications adhesives can contribute up to 5% of total pack weight.

Once adhesive content exceeds 1% of the pack’s dry weight, EN 13432 requires the adhesive itself to be certified as compostable. Without that certification, even an otherwise compostable pack risks failing compliance.

What EN 13432 requires of adhesives

For adhesives to comply with EN 13432, they must:

• Biodegrade by at least 90% within six months under industrial composting conditions (~58°C, with regulated oxygen and moisture)
• Disintegrate into pieces smaller than 2mm within 12 weeks
• Leave no harmful residues, such as microplastics, heavy metals, or ecotoxic effects on plant growth

If adhesives cannot demonstrate this through independent certification, the packaging claim will fail.

The documentation converters need

Under PPWR and EPR schemes, claims must be backed up by evidence. For adhesives, this means:

• EN 13432 or ASTM D6400 certification from accredited labs.
• Technical data sheets outlining composition and application details.
• Traceability documentation to prove consistent sourcing and performance.

Without this evidence, compostability claims risk being challenged by regulators, retailers, or NGOs (Non-Governmental Organisations).

Adhesives may once have been treated as a minor detail, but under the 1% rule they are front and centre in compostability compliance. For converters, this means adhesive choice is a strategic decision.

By selecting certified compostable hot melts, converters can not only meet regulatory requirements but also protect brand credibility, avoid compliance risks, and ensure packaging truly lives up to its sustainability promise.

The 1% rule makes it clear that adhesives are no longer just a background material in packaging. They can be the difference between compliance and rejection, between a credible sustainability claim and one that falls apart under scrutiny.

For converters, the safest path is to choose adhesives that are independently certified as compostable and supported with full documentation. Power Adhesives was the first to launch a certified biodegradable hot melt range and continues to expand it to meet the challenges of PPWR. By switching to proven solutions, converters can de-risk their packaging and demonstrate to customers and regulators alike that their sustainability claims are built on solid ground.

Explore Power Adhesives’ biodegradable hot melt range here.