Formulators and procurement teams evaluating propylene glycol (PG) alternatives are increasingly landing on bio-based 1,3-propanediol — not simply as a sustainability gesture, but as an ingredient that can deliver measurable performance advantages across a number of key applications.
This post outlines what bio-based 1,3-PDO is, how it compares to conventional PG, and where the business case for switching is most compelling.
What Is Bio-Based 1,3-PDO?
1,3-Propanediol (1,3-PDO, also known as trimethylene glycol) is a small diol molecule that functions as a humectant, co-solvent, viscosity modifier, and formulating intermediate across a wide range of industrial and consumer applications.
It shares the same molecular formula as propylene glycol (C₃H₈O₂) but differs in the position of its hydroxyl groups — a structural distinction that produces meaningful differences in physical behavior.
Conventionally, 1,3-PDO was produced from petroleum feedstocks, which limited its commercial reach. Today, a mature fermentation process converts corn sugar into 1,3-PDO with the same chemical identity as the petrochemical version — but with full bio-based certification, a reduced carbon footprint, and eligibility for “renewable” and “naturally derived” labeling claims.
This combination of performance and provenance is driving growing adoption across multiple sectors.
How It Compares to Propylene Glycol
PG has been a workhorse ingredient for decades — well characterized, broadly available, and cost-competitive.
The decision to evaluate 1,3-PDO isn’t about replacing something that isn’t working. It’s about identifying where 1,3-PDO’s specific property profile delivers a better outcome, or where bio-based certification changes the value equation for your customer base.
| Property | Propylene Glycol (PG) | Bio-Based 1,3-PDO |
|---|---|---|
| Feedstock origin | Petroleum-derived | Corn sugar (renewable, bio-based certified) |
| Boiling point | ~187°C (369°F) | ~214°C (417°F) |
| Freezing point | ~−57°C (−71°F) | ~−25°C (−13°F) |
| Viscosity at 20°C | ~56 cP | ~52 cP |
| Viscosity at 0°C | ~250 cP | ~150 cP (~40% lower) |
| Surface tension at 20°C | 36 mN/m | ~40 mN/m |
| Skin irritation potential | Moderate | Lower sensitization potential |
| Water solubility | Completely miscible | Completely miscible |
| Hygroscopicity | Very high | Very high |
| Sustainability claim | None | Renewable feedstock, reduced CO₂ |
The two most practically significant differences are low-temperature viscosity and bio-based origin.
At 0°C, 1,3-PDO’s viscosity is roughly 40% lower than PG — a difference that matters considerably in antifreeze and heat transfer fluid (HTF) formulations where cold-flow performance directly affects pumping efficiency and heat exchange. The higher boiling point also extends the effective operating range in thermal applications.
In most personal care, food-grade, and industrial fluid applications, the transition from PG to bio-based 1,3-PDO is a relatively low-friction process — same function, improved performance profile, and a supply chain that is now well-established at commercial scale.
Application-by-Application Assessment
Personal Care and Cosmetics
This is the sector where 1,3-PDO’s advantages are most immediately visible to end users.
Its lower cold-temperature viscosity translates to improved spreadability and a lighter skin feel compared to PG. Studies indicate a lower sensitization and irritation potential, making it a better fit for sensitive skin formulations, “clean beauty” positioning, and products targeting consumers with known PG sensitivity.
Its excellent optical clarity is an additional benefit for transparent serums, gels, and tonics. For brands making natural or minimally processed claims, the bio-based origin of 1,3-PDO can be directly communicated on the label.
Antifreeze and Heat Transfer Fluids
The 40% reduction in viscosity at low temperatures is a direct performance gain for HTF system designers.
Lower viscosity at cold-start conditions means reduced pumping energy requirements and more efficient heat transfer across the operating range. The higher boiling point of ~214°C improves thermal stability and extends the effective service temperature ceiling compared to PG-based fluids.
For commercial HVAC, industrial process cooling, and ground-source systems, 1,3-PDO is considered a near drop-in replacement, with validation requirements limited primarily to blend ratios and inhibitor compatibility.
Food and Beverage
Both PG and 1,3-PDO are recognized as safe humectants, solvents, and stabilizers in food applications.
A switch to bio-based 1,3-PDO requires regulatory label updates and internal stability validation, but the transition complexity is low in most cases. The bio-based origin adds meaningful value for food brands with sustainable sourcing commitments or those positioning toward natural and clean-label consumer segments.
Polymers and Performance Textiles
Bio-based 1,3-PDO is the primary monomer for polytrimethylene terephthalate (PTT), a high-performance polyester fiber that offers superior stretch and recovery compared to conventional PET.
PTT produced from renewable 1,3-PDO is an established material in sustainable performance apparel and technical textile markets. This application requires full polymer design qualification, but the downstream material properties — and the ability to market the fiber as bio-based — make the development investment well justified for manufacturers operating in that space.
Pharmaceuticals
Pharmaceutical substitution carries the highest qualification burden of any sector. API solubility, bioavailability, stability, and excipient compatibility must all be independently validated, and both EP and USP grade standards apply.
The switch is technically feasible but requires a structured revalidation program. Organizations that complete that process benefit from a solvent that meets the same functional requirements as PG while offering improved skin tolerance in topical applications.
The Sustainability Case for B2B Procurement
For procurement and sourcing teams, bio-based 1,3-PDO represents an opportunity to reduce the fossil-derived content of a formulation without accepting a performance trade-off.
The fermentation production route yields a product with a lower lifecycle carbon footprint than petroleum-derived PG, and bio-based certification is available for supply chain documentation and scope 3 emissions reporting purposes.
As customer sustainability requirements become more common in supplier qualification processes, having a bio-based alternative already qualified and in use is a straightforward way to reduce procurement risk.
For formulators selling into markets where “bio-based content” is a differentiating claim — personal care, food, textiles — 1,3-PDO sourced from a certified renewable supply chain enables that claim directly.
Summary
Bio-based 1,3-PDO is not a niche or emerging ingredient. It is commercially available at scale, well characterized across multiple application sectors, and increasingly specified by formulators who need both the performance profile and the sustainability credentials.
For companies currently using propylene glycol in personal care, HTF, or food-grade applications, the evaluation is worth undertaking. The qualification path is generally manageable, the performance data supports the switch in most use cases, and the supply chain is reliable.
Interested in Sourcing Bio-Based 1,3-PDO?
J R Hess Company works directly with producers of fermentation-derived 1,3-PDO and can support your qualification process from initial sampling through ongoing supply. Whether you’re in early evaluation or ready to move to commercial volumes, we can help you navigate the transition.
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