PHA (Polyhydroxyalkanoates): biodegradable and sustainable

PHA is a biodegradable and environmentally friendly material, produced from natural bacterial fermentation of plant-based raw materials. Combines good mechanical properties with compostability.

Example of an injection molded plastic part, QDP product photography

Key properties

Biodegradable in soil and water, without microplastics.
Produced from renewable plant-based raw materials.
Good mechanical strength and toughness, comparable to PP.
Water- and moisture-resistant.
Compostable in both industrial and home composting systems.

Mechanical properties (indicative values)

Property	Value
Density	1.20-1.25 g/cm³
Tensile strength	20-40 MPa
E-modulus (tensile)	1000-3500 MPa
Elongation at break	5-15%
HDT @1.8 MPa	60-120 °C
Shrinkage	1,0-2,0%
Processing temperature	160-180 °C

Indicative values for standard, unfilled grades. For a definitive material choice, always consult the supplier datasheet (TDS) of the specific grade.

Applications

Packaging industry: compostable food packaging
Consumer products: biodegradable cups and plates
Medical applications: biocompatible packaging
Agricultural sector: plant pots and mulch films

Why choose PHA?

QDP works for PHA with Bluepha (TÜV and EFSA certified, marine and compost biodegradable). For PHA, the material price is usually the bottleneck for adoption, not the technology: we always discuss this early in the process.

See the full materials overview or the DfM-pillar.

Frequently asked questions about PHA

What is PHA?

PHA is a biobased plastic that bacteria produce as a reserve supply, fed with plant-based raw materials. It is not a petroleum product and it is biodegradable, also outside an industrial composting facility. In terms of properties, it is close to PP, with a tensile strength of 20 to 40 MPa. It can be injection molded as normal. QDP has processed PHA, among other things, into a dosing spoon with a statement for food contact.

What is the difference between PHA and PLA?

Both are biobased and degradable, but the conditions differ greatly. PLA requires an industrial composting facility, with high temperature and a controlled process; in an ordinary compost heap or in the sea, little happens. PHA also degrades in those environments. On the other hand, PHA is more expensive and less widely available. QDP makes the choice based on whether degradability is truly required in use.

Is PHA really biodegradable, also in nature?

Yes, that is the distinguishing feature of this material. Where most so-called degradable plastics only break down in an industrial facility, PHA also breaks down in soil and in seawater. How fast depends on the thickness of the product and the conditions, so it is not a license to throw things away. It is a solution for products that inevitably end up in the environment. QDP only uses it for that, not as a green trim.

What does PHA cost compared to regular plastic?

Multiples. PHA is produced in small volumes via fermentation, and this process is expensive compared to the petrochemical industry that produces PP and PE. In practice, the price is the reason projects stall, not the technology: the material can be processed just fine. For small, high-value products it can be viable, for mass products usually not. QDP works this out in advance instead of after the fact.

What do you use PHA for?

For products that end up in the environment or where degradability is truly functional: single-use packaging, agricultural and horticultural articles that remain in the ground, and small consumer items with a sustainability claim that must be substantiated. For a structural part that needs to last twenty years, it is not a logical choice. QDP first assesses whether the application justifies the extra cost.

What does this mean for your design?

Calculate your mold and unit price in 2 minutes, or ask our engineers for a DfM check.

Calculate your price Schedule brainstorm