PHA Polymer: an Overview of this Fantastic Bioplastic

According to the European Bioplastics organisation, the different types of PHA are either biodegradable of biological origin, biodegradable of fossil origin or compostable of biological origin, but not simply biodegradable.

What is PHA?

Polyhydroxyalkanoates (PHA) are biopolymers produced naturally by certain bacteria. When these bacteria are exposed to nutrient stress (lack of nitrogen, phosphorus) and excess carbon, they produce the famous PHA. Obviously, this defensive reflex is triggered in a controlled microbial environment (temperature, humidity, etc.).

PHA Production

As you will have gathered, PHA production is the result of a fermentation process. These polymers are stored by the bacterial cells (granules) to be used as a source of energy in times of shortage. PHAs can be chemically modified to produce a wide range of plastic materials with varying properties. From rigid plastics to flexible films, PHAs have many properties.

N.B. Renewable raw materials or organic waste can also be used to produce PHA.

PHA Applications

PHA has similar properties to many conventional plastics, particularly in terms of mechanical strength and durability. Its added advantage is that it is 100% biodegradable! PHA products can be used for all kinds of everyday objects and applications in various industries:

• Biodegradable bags, packaging films, household items, disposable crockery, etc.
• Food packaging, agricultural products and marine applications
• Medical sutures and materials for absorbable medical devices
• Elastic materials, adhesives and components for 3D printing
• Coating materials for capsules and transdermal patches

Studies: the Positive Environmental Impact of PHA

Environmental studies highlight the ability of PHAs to reduce plastic pollution. Unlike traditional plastics, which last for centuries, PHAs biodegrade in a matter of months or years.

Biodegradability of PHAs in various environments

PHAs biodegrade completely in soils, freshwater and oceans. Their decomposition generates carbon dioxide and water, without toxic products. This biodegradability is crucial to reducing marine pollution, a major environmental problem. OECD research shows that PHAs can reduce microplastics in the oceans.

PHA = Reduced Greenhouse Gas Emissions

The production of conventional plastics generates significant greenhouse gas emissions. Producing PHAs from renewable raw materials reduces these emissions. Plants capture carbon dioxide as they grow, partially offsetting the emissions. Using organic waste as a raw material to produce PHA therefore reduces CO2 emissions. PHA’s carbon emissions are lower, and the planet and its inhabitants are one and the same.

Renewable and Biodegradable Materials

PHAs have similar properties to conventional plastics, such as strength and durability. However, they are fully biodegradable, a major advantage for the environment. Unlike petrochemical plastics, they break down naturally in nature. Compared with their traditional cousins, PHAs leave no hazardous residue in the environment.

Zoom on PHA Environmental Certifications

PHA’s environmental certifications provide assurance of its durability and performance as a biodegradable and compostable material. They enable companies – and consumers – to choose environmentally-friendly alternatives.

• OK Compost” certification from TÜV Austria: guarantees that the material is compostable in an industrial environment, where temperatures are high enough to accelerate the decomposition process.

NB. “OK Compost Home” is a variant which certifies that a product is compostable under domestic conditions.

• European certification EN 13432: specifies the requirements for compostable and biodegradable packaging. The material decomposes without releasing toxic substances, and at least 90% of it is broken down within six months.
• ASTM D6400 certification (United States): the material must biodegrade under industrial composting conditions in a given time without causing toxic pollution.
• Vinçotte “OK Biodegradable” certification: validates that the material biodegrades completely in specific environments such as soil (OK Biodegradable Soil) or water (OK Biodegradable Water).
• ISCC Plus (International Sustainability & Carbon Certification): for products that meet sustainability criteria throughout the supply chain. Aspects relating to greenhouse gas emissions and the sustainable use of resources are taken into account.
• USDA BioPreferred certification: the US Department of Agriculture programme certifies that the material contains a minimum percentage of bio-based materials.
• BPI (Biodegradable Products Institute) certification: certified products must meet strict biodegradability and compostability standards.
• Cradle to Cradle certification: an environmental standard focusing on eco-design and the circular economy.

Environmental Framework: The Future of HAPs

PHAs have a promising future in a circular and sustainable economy. Governments and industry are looking for more environmentally-friendly solutions, and PHA is one of them. These bioplastics help to reduce our dependence on petrochemical plastics. Investing in research is essential if we are to overcome the technical and ecological challenges.

Environmental studies on PHA demonstrate their potential as an alternative to traditional plastics. PHA makes it possible to reduce plastic pollution and limit greenhouse gas emissions. Biosourced and biodegradable: innovations in sustainable materials could make PHA the solution for years to come.