At ORY®, we believe you should know what’s in your products and why. This page lists the published research behind what we say about propanediol (1,3-propanediol). Each section starts with our claim, then tells you how well the research supports it, then lists the sources so you can read them yourself.
How to read this page Supported — backed by peer-reviewed research or official safety reviews. Supported, with caveats — the research points this way, but mostly from laboratory or animal studies, or at different strengths than ORY® uses. Limited evidence — little or no published research yet. We say so openly. |
1. General Description and Role
Claim: Propanediol (1,3-propanediol) is a clear, odorless glycol made by fermenting corn sugar. In ORY® products, it is a humectant that helps skin and hair hold moisture, a solvent for other ingredients, and a helper for preservatives. |
Verification: Supported. The Cosmetic Ingredient Review (CIR) Expert Panel concluded that propanediol is safe in cosmetics in the present practices of use and concentration. In human tests summarized by CIR, it was not sensitizing at 5–75%.
Citations:
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
- What it shows: CIR safety assessment of alkane diols, including propanediol.
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
2. Composition and Production
Claim: Propanediol is produced by fermenting glucose from corn and purifying it by distillation. It is a different chemical from propylene glycol (1,2-propanediol). |
Verification: Supported. Its chemistry is well documented.
Citations:
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
- What it shows: Describes chemistry.
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
3. Skin Type Suitability
Claim: Propanediol suits all skin types, including sensitive skin. |
Verification: Supported. CIR found it non-sensitizing in human testing. Propylene glycol, a related but different glycol, was named Allergen of the Year in 2018; propanediol is a common alternative.
Citations:
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
- What it shows: Human sensitization data.
- Jacob, S. E., Scheman, A., & McGowan, M. A. (2018). Propylene glycol. Dermatitis, 29(1), 3–5. https://doi.org/10.1097/DER.0000000000000315
- What it shows: Propylene glycol allergy (for comparison).
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
4. Hair and Scalp Suitability
Claim: In haircare, propanediol adds light moisture and helps dissolve scalp-care ingredients. |
Verification: Supported. This is a formulation role; ORY® haircare products are not intended to treat dandruff or scalp conditions.
Citations:
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
- What it shows: Reported uses.
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
5. Benefits
Claim: Propanediol helps skin and hair feel moisturized with a light, non-sticky feel and helps products stay stable. |
Verification: Supported. By lowering the free water available to microbes, glycols can support preservatives, but they do not replace them.
Citations:
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
- What it shows: Describes functions.
- Lundov, M. D., Moesby, L., Zachariae, C., & Johansen, J. D. (2009). Contamination versus preservation of cosmetics: A review on legislation, usage, infections, and contact allergy. Contact Dermatitis, 60(2), 70–78. https://doi.org/10.1111/j.1600-0536.2008.01501.x
- What it shows: Review of preservation.
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
6. Use Across ORY® Product Lines
Claim: Propanediol is used in all four ORY® product lines. |
Verification: Supported. Use levels fall well within the ranges CIR reviewed (reported up to about 40%).
| Product line | Typical level | How ORY® uses it |
| Skincare | 2–10% | Serums, toners, creams, gels, and cleansers. |
| Haircare | 2–8% | Leave-ins, scalp tonics and serums, conditioners, and shampoos. |
| Handmade Soap | 1–5% | Liquid, syndet, and melt-and-pour soap; small amounts in cold-process. |
| Cosmetics | 2–10% | Foundations, setting sprays, mascaras, and lip products. |
Citations:
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
- What it shows: Reported use concentrations.
- U.S. Food and Drug Administration. 21 CFR 701.20 — Definition of “soap” (only true soap, made mainly of alkali salts of fatty acids and sold only as soap, is exempt from cosmetic rules). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-G/part-701/subpart-B/section-701.20
- What it shows: FDA definition of soap; other bars are cosmetics.
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
7. Pros
Claim: A plant-derived, low-sensitization humectant and solvent with a CIR safety conclusion. |
Verification: Supported. Supported by CIR human testing.
Citations:
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
- What it shows: Safety conclusion.
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
8. Cons
Claim: Propanediol costs more than propylene glycol and can increase how much of other ingredients reach the skin. |
Verification: Supported. We list these limits so you have the full picture:
- Cost. Higher than propylene glycol.
- Penetration. Can increase absorption of other ingredients; used carefully with strong actives.
- Not a preservative. Supports, but does not replace, preservatives.
- Sourcing. Corn-derived; specify non-GMO where required.
Citations:
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
- What it shows: Safety data.
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
9. Safety Notes
Claim: Patch test before use; for external use only. |
Verification: Supported. Follow these precautions:
- Patch test any new product on a small area for 24–48 hours before full use.
- Stop use if redness, burning, itching, or rash occurs, and talk to a healthcare provider.
- For external use only. Avoid the eyes unless the product is made for the eye area.
- If you are pregnant, nursing, have a medical condition, or are buying for a child, ask a healthcare provider before use.
Citations:
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
- What it shows: Safety conclusion.
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
10. Product-line notes
- ORY® Skincare: For external use only. Not for deep or puncture wounds, animal bites, or serious burns.
- ORY® Haircare: Designed for the look and feel of hair and scalp comfort. Not intended to treat dandruff or scalp conditions, or to promote hair growth or prevent hair loss.
- ORY® Handmade Soap: Propanediol is used mainly in liquid, syndet, and melt-and-pour products, which are cosmetics under FDA rules and list all ingredients. Not intended to treat eczema or any skin condition.
- ORY® Cosmetics: Do not share applicators, and replace any product that changes color, smell, or texture.
11. References
Peer-reviewed research
- Jacob, S. E., Scheman, A., & McGowan, M. A. (2018). Propylene glycol. Dermatitis, 29(1), 3–5. https://doi.org/10.1097/DER.0000000000000315
- Lundov, M. D., Moesby, L., Zachariae, C., & Johansen, J. D. (2009). Contamination versus preservation of cosmetics: A review on legislation, usage, infections, and contact allergy. Contact Dermatitis, 60(2), 70–78. https://doi.org/10.1111/j.1600-0536.2008.01501.x
- Scott, L. N., et al. (2024). Safety assessment of alkane diols as used in cosmetics (including propanediol). International Journal of Toxicology, 43(2 Suppl), 70S–131S. https://doi.org/10.1177/10915818231224234
Government and regulatory sources
- U.S. Food and Drug Administration. 21 CFR 701.20 — Definition of “soap” (only true soap, made mainly of alkali salts of fatty acids and sold only as soap, is exempt from cosmetic rules). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-G/part-701/subpart-B/section-701.20
