Bioplastics are plastic materials produced partially or wholly from renewable biomass sources like plants and microbes rather than traditional petrochemicals. The two names that come up in almost every conversation are PLA and PHA. They are often treated as interchangeable which they’re not. And picking the wrong one could be an expensive mistake.
For the matter of scale, all bio-based plastics together still make up less than 1% of global plastic output (Javed et al., 2026).
What is PLA?
PLA stands for polylactic acid. It is a polyester built from lactic acid, the same acid that turns milk sour.
- Raw materials: Plant starch and sugars, usually from corn or sugarcane.
- Process: Microbes ferment the sugar into lactic acid, then chemists join those lactic acid molecules into long chains, which is then purified and polymerized to form PLA. The polymer is converted into pellets, which are further processed by methods such as extrusion or injection molding to produce packaging materials, films, bottles, or other products.
- Common applications: Rigid trays, cups, cutlery, bottles, films and coatings for food packaging.
- Advantages: PLA is the most commercially mature bioplastic on the market, rated at technology readiness level 9, meaning fully proven at commercial scale. It runs on standard plastics machinery, and is cheaper as well. Production cost estimates for the corn grain route sit at USD 1.00 TO1.37 per kilogram (Wellenreuther et al., 2022).
- Limitations: PLA is brittle, and its gas barrier is modest, though surface modification can improve it by up to 70% (Jawed et al., 2026). The bigger catch is disposal. PLA does not biodegrade at room temperature, so it needs an industrial composting facility or otherwise it will behave like an ordinary plastic in the environment.
What is PHA?
PHA stands for polyhydroxyalkanoates, which are a family of natural, biodegradable bioplastics produced through bacterial fermentation. Microorganisms synthesize these polymers as an energy reserve when fed renewable resources like sugars or plant oils.
- Microbial Production: Bacteria make PHA inside their own cells and store it as an energy reserve, roughly the way humans store fat. There is no separate chemical polymerization step as the microbe does the whole job, and the polymer is harvested from the cells.
- Types: More than 150 monomer building blocks have been identified, which is why PHA covers everything from stiff thermoplastics to rubbery grades (Koller et al., 2025). The common ones are PHB, PHBV, PHBH and P(3HB-co-4HB).
- Raw materials and fermentation: Sugar, plant oils and agricultural or industrial waste streams are fed to the microbes in a fermenter. Feedstock account for over 40% of total operating cost, which is why waste-based carbon is the main route to cheaper PHA.
- Common application: Films, coatings, flexible packaging, cosmetic microbeads and specialty items.
- Advantages: PHA offers excellent oxygen barrier performance (Javed et al., 2026) and it breaks down in fresh water, seawater, soil, home composting and industrial composting (Koller et al., 2025).
- Limitations: Poor thermal stability, demonstration-scale supply rather than full commercial scale (Javed et al., 2026), and a high cost.
PLA vs PHA: A Comparative Table
| Parameter | PLA | PHA |
| What it is | Polyester polymerised from lactic acid | Polyester made and stored inside living bacteria |
| Raw material | Plant starch and sugars (corn, sugarcane) | Sugars, plant oils and waste streams fed to microbes |
| How it is made | Fermentation to lactic acid, then chemical polymerisation | Fermentation only; polymer harvested from the cells |
| Family size | One main polymer | Over 150 monomers: PHB, PHBV, PHBH, P(3HB-co-4HB) |
| Oxygen barrier | Modest; surface treatment can improve it up to 70% | Excellent |
| Thermal stability | Better of the two | Poor |
| Flexibility | Brittle | Grade-dependent, rigid through rubbery |
| Industrial composting | Yes | Yes |
| Home compost and soil | No, not at room temperature | Yes |
| Seawater | No | Yes |
| Indicative cost | USD 1.00-1.37 per kg (corn grain route) | EUR 2.82 to USD 6.29 per kg (PHBV) |
| Commercial readiness | TRL 9, fully commercial | Demonstration scale |
| Best-fit formats | Rigid trays, cups, cutlery, bottles | Films, coatings, microbeads, specialty items |
Sources: Javed et al. (2026); Koller et al. (2025); Naser et al. (2021); Wellenreuther et al. (2022); Atarés et al. (2024); Dhatt et al. (2025); Hyodo et al. (2024).
When Should a Brand Choose PLA?
PLA can be a good choice when a brand wants a sustainable material that is practical, affordable, and already available at a large scale. Consider PLA if your product is manufactured in large quantities, since PLA is commercially produced and can handle high-volume orders. It also works well with existing manufacturing equipment, such as standard extrusion and thermoforming machines, meaning companies usually do not need major changes to their production setup.
Cost is another important advantage. At around USD 1.00–1.37 per kg, PLA is considerably more affordable than PHA and is closer to the price range of conventional plastics. Its rigidity and stiffness also make it suitable for products such as trays, cups, and clamshell packaging. For products with a short to medium shelf life, its moderate gas-barrier properties are generally sufficient.
When Should a Brand Choose PHA?
PHA becomes more attractive when biodegradability and end-of-life flexibility are the main priorities. Unlike PLA, PHA can biodegrade under a wider range of conditions, including freshwater, seawater, soil, and both industrial and home composting environments. This makes it a useful option when a brand cannot rely on a single disposal system.
PHA can also support a premium sustainability image, particularly for brands that want stronger environmental credentials. For example, PHA microbeads placed at a depth of 757 metres in the Pacific Ocean showed visible degradation within five months (Hyodo et al., 2024), while PHB films buried in saturated soil completely degraded within two weeks (Kim et al., 2023).
PHA is also versatile because different grades can range from rigid to flexible or rubber-like materials, and it generally offers a better oxygen barrier than PLA.
PHA/PLA Blends
Brands do not always have to choose. Blending amorphous PHA into PLA makes the result less brittle while keeping PLA’s cost and processing advantages. Blends at 90% and 75% PLA kept their tensile properties through five extrusion heat cycles, which means factory scrap can be fed back into new resin rather than thrown away (Chatrath et al., 2024).
For many brands, a blend is the sensible first step as it provides most of the PLA’s economics as well as PHA’s toughness and versatility.
How TerraPHA Helps
TerraPHA Biotech is World’s first non-GMO biopolymer company, producing PHA using naturally occurring microbial system. It uses precision fermentation processes to make sure the material is produced consistently and can be made on a larger scale.
The company works from diverse renewable feedstocks including waste streams, converting organic and industrial wastes into higher-value material. This flexibility makes the production process more adaptable.
Frequently Asked Questions
Is PLA biodegradable?
Only under the right conditions. PLA does not break down at room temperature and needs industrial composting. Without the appropriate condition, it behaves like a conventional plastic only.
Can PHA can be run on existing PLA line?
It would require some adjustments. PHA’s different stability, processing temperatures and residence time would require some refinement and re-adjustments. Ask the supplier for grade-specific data before a trial.
Will PHA ever cost the same as PLA?
The route to lower cost feedstock, which accounts for over 40% of PHA operating cost. Waste-based carbon narrows the gap; full parity with PLA is not here yet.
References
Atarés, L., Chiralt, A., González-Martínez, C., & Vargas, M. (2024). Production of polyhydroxyalkanoates for biodegradable food packaging applications using Haloferax mediterranei and agrifood wastes. Foods, 13(6), 950. https://doi.org/10.3390/foods13060950
Chatrath, S., Alotaibi, M., & Barry, C. F. (2024). Performance of recycled polylactic acid/amorphous polyhydroxyalkanoate blends. Polymers, 16(9), 1230. https://doi.org/10.3390/polym16091230
Dhatt, P. S., Hu, A., Hu, C., Huynh, V., Dai, S. Y., & Yuan, J. S. (2025). Biomimetic layered, ecological, advanced, multi-functional film for sustainable packaging. Nature Communications, 16, 6649. https://doi.org/10.1038/s41467-025-61693-2
Hyodo, N., Gan, H., Ilangovan, M., Kimura, S., Kasuya, K., Isobe, N., & Iwata, T. (2024). Coastal and deep-sea biodegradation of polyhydroxyalkanoate microbeads. Scientific Reports, 14, 10302. https://doi.org/10.1038/s41598-024-60949-z
Javed, A., Mehmood, W., Bhatnagar, A., & Dessbesell, L. (2026). Bio-based plastics in food packaging: Performance, environmental impact, end-of-life, technology readiness level and market trends. Applied Food Research, 6, 102219. https://doi.org/10.1016/j.afres.2026.102219
Kim, J., Gupta, N. S., Bezek, L. B., Linn, J., Bejagam, K. K., Banerjee, S., Dumont, J. H., Nam, S. Y., Kang, H. W., Park, C. H., Pilania, G., Iverson, C. N., Marrone, B. L., & Lee, K.-S. (2023). Biodegradation studies of polyhydroxybutyrate and polyhydroxybutyrate-co-polyhydroxyvalerate films in soil. International Journal of Molecular Sciences, 24(8), 7638. https://doi.org/10.3390/ijms24087638
Koller, M., Heeney, D., & Mukherjee, A. (2025). Biodegradability of polyhydroxyalkanoate (PHA) biopolyesters in nature: A review. Biodegradation, 36(4), 76. https://doi.org/10.1007/s10532-025-10164-y
Naser, A. Z., Deiab, I., & Darras, B. M. (2021). Poly(lactic acid) (PLA) and polyhydroxyalkanoates (PHAs), green alternatives to petroleum-based plastics: A review. RSC Advances, 11(28), 17151-17196. https://doi.org/10.1039/d1ra02390j
Wellenreuther, C., Wolf, A., & Zander, N. (2022). Cost competitiveness of sustainable bioplastic feedstocks: A Monte Carlo analysis for polylactic acid. Cleaner Engineering and Technology, 6, 100411. https://doi.org/10.1016/j.clet.2022.100411
