Driving Compostable Packaging Solutions with PHA & PLA Innovations

By Leah Ford, CJ Biomaterials

The packaging industry is under growing pressure from both consumers and regulatory agencies to develop eco-friendly alternatives that reduce landfill waste and lower environmental impact. Innovations in biopolymer technology—including advancements with polylactic acid (PLA) and polyhydroxyalkanoate (PHA)—are enabling organizations to meet these sustainability goals while maintaining the performance required for rigid and flexible food packaging solutions at a commercial scale.

Film masterbatches and compounds made with PLA and PHACT™ PHA have been developed for flexible food packaging that offer highly functional and tunable, compostable alternatives to traditional polyethylene (PE) and polypropylene (PP) films. Image courtesy of CJ Biomaterials.

Compostable Packaging Innovations

PLA has demonstrated that it is an ideal material option for sheet extrusion and thermoforming due to its strength and performance benefits. Produced from annually renewable resources,  PLA appeals to brands and consumers who prefer to use third-party certified safe, compostable, 100% biobased, low-carbon packaging materials that enable the diversion of both food scraps and packaging away from landfills into the expanding industrial composting infrastructure. Combining amorphous PHA (aPHA) with PLA for thermoformed food packaging improves throughput during thermoforming, increases impact strength, accelerates the rate of compostability, and maintains transparency, clarity, and biobased content. As brands are introducing compostable food packaging at larger scale, improved impact resistance is critically important for packaging used in automated food packaging systems.   Specific brands of PHA and PLA are also both cleared for food contact use by the U.S. Food & Drug Administration (FDA) via their Food Contact Notifications (FCNs).

Beyond rigid thermoformed packaging, flexible food packaging is another area seeing rapid innovation. PHA-PLA film masterbatches and compounds have been developed that offer highly functional and tunable, compostable alternatives to traditional polyethylene (PE) and polypropylene (PP) films. A commercially available PHA-based masterbatch series, designated MA1250P, recently received OK compost HOME certification from TÜV AUSTRIA and is designed for use in biaxially oriented, blown and cast film applications. The MA1250P-A grade in particular is designed for using in sealant layer film applications as it improves seal strength and flexibility over neat PLA alone. Films made with PHA-PLA masterbatches and compounds are particularly suited for food packaging, including frozen food applications.

A recent collaboration between Pregis and CJ Biomaterials on films for frozen foods was recently on display at the SPC IMPACT conference in Seattle. This bag is part of Pregis’ Renew™ Series of flexible packaging solutions and features certified compostable and renewable materials.

Additionally, advancements in PHA-PLA flexible films have demonstrated their potential in machine direction orientation (MDO) processes, achieving high shrinkage rates and enabling their use as a replacement for conventional shrink wrap films. These films also offer breathability when mineral-filled, making them suitable for specialized applications where moisture control is necessary.

Enhancing the Compostability of Packaging Materials

A critical aspect of sustainable packaging is ensuring that materials meet stringent compostability certifications. In the US, the Biodegradable Products Institute (BPI) is the leading third-party certifier of compostable products. BPI’s certification is based on American Society for Testing and Materials (ASTM) standards D6400 and D6868, which set pass/fail criteria for the disintegration, biodegradation, and ecotoxicity of compostable materials.

Pregis and CJ Biomaterials collaborated on developing a compostable, flexible film structure made with PHA and PLA for frozen foods. Image courtesy of Pregis.

These standards documented in the US Composting Council’s (USCC) composting handbook, were modeled after compost conditions needed to safely kill weeds, seeds, and pathogens in food scraps. Compostable packaging has been designed to breakdown in the environment needed to safely compost food scraps which also ensures that compostable products can safely degrade and contribute to high-quality compost. In addition to standards-based testing, BPI requires that submitted products are free of per- and polyfluoroalkyl substances (PFAS) and other fluorinated chemicals. Both PLA and PHA have passed this testing and carry BPI certification.

Recent legislation in several states including California, Minnesota, and Colorado has significantly increased the amount of food scraps being sent to industrial composters. In response, some composters have turned to accelerated composting processes to accommodate the increased volumes of food scraps. This shift has created demand for faster-degrading compostable products. Completed biodegradation testing shows that the new PLA/aPHA formulation can biodegrade within 60 days at industrial composting temperatures. Results from a field disintegration study in an industrial aerated static pile have shown that a combined PLA-PHA solution has a high probability of degrading within the 60-day timeframe under field conditions.

As more functional, compostable packaging becomes available to consumers, there has been simultaneous growth in access to commercial composting facilities. From 2021-2023, the number of households in the U.S. with access to food waste collection grew by 49% — from 10.0 million to 14.9 million households according to a survey published by Biocycle. To further grow access, the EPA published a study in January that estimates it would require an investment of $14 to $16 billion for improvements to curbside collection, drop-off, and processing infrastructure so that access to commercial composting is on par with access to trash disposal. Through investment from cities, states, private companies, and public-private partnerships, the rate of organics recycling could increase from 28% to 68% and achieve a meaningful reduction in environmental impact.

Environmental Benefits of Compostable Packaging

In the thermoforming space, PLA/aPHA blends stand out as a sustainable solution for rigid packaging. Using these two certified-biobased polymers increases the use of annually renewable feedstocks, reduces the carbon impact of materials, and decreases reliance on fossil-fuel feedstocks. As certified compostable materials available from specific commercial sources, PLA and PHA can create packaging that does not contribute to persistent microplastics in the environment and helps enable the diversion of food scraps away from landfills and into composting systems.

Food degrading in landfills is the third-largest source of methane emissions in the US. In contrast, aerobic composting does not force the generation of methane and instead produces a valuable soil amendment that improves soil biodiversity and water retention properties. These cumulative benefits for our climate are why the composting and compostable products industry is adopting science-based certifications to ensure compostable products are non-toxic and properly degrade in industrial compost environments.

Looking Ahead

As organizations continue to prioritize sustainability, PHAs and PLAs remain critical materials in the next generation of eco-friendly, high-performance packaging. While the biopolymer industry has faced challenges, including recent market shifts and the shutdown of production facilities, the market is mature enough that there is considerable efficiency and resiliency in the supply chain to weather these changes especially as the long-term market potential remains strong.

Over the past 30 years, the industry has consistently evolved to deliver innovative, sustainable solutions. Continued investment, innovation, and strategic partnerships are enabling the industry to scale effectively and meet the growing demand for compostable packaging solutions. By advancing material performance, securing third-party certifications, and expanding industrial composting infrastructure, companies in the bioplastics sector will continue to help drive a more circular economy—one where packaging waste is minimized, and environmental benefits are maximized.

About the Author

Leah Ford is the Director of Marketing for CJ Biomaterials, a leading manufacturer of PHA biopolymers under the brand name PHACT™️. Previously, Leah spent 19 years working at NatureWorks in progressive roles including as a business analyst, digital marketing manager, and global marketing and communications director. Visit: https://cjbiomaterials.com/