In modern cosmetic and personal care formulation, the trend is clear: consumers want "clean label" products—fewer synthetic preservatives, no parabens, and reduced allergenicity—yet they still demand a shelf life of 12–24 months. Traditional preservative systems (phenoxyethanol, methylparaben, MIT) often clash with this expectation. AscendPro® HG / HG-N (INCI Name: 1,2-Hexanediol) is a multifunctional humectant and mild antimicrobial booster that helps formulators meet that challenge. It does not aim to replace a full preservative system in high-water-activity products on its own, but it extendspreservative efficacy when used in combination, while delivering notable humectancy and skin-softening benefits. The question formulators often ask is: can 1,2-hexanediol really reduce the need for traditional preservatives, and how should it be incorporated into a "green" or sensitive-skin friendly preservation strategy?
What Is 1,2-Hexanediol (AscendPro® HG)?
AscendPro® HG is a high-purity 1,2-Hexanediol (C₆H₁₄O₂, EC No. 230-029-6)—a colorless, low-odor, water-soluble diol produced via catalytic hydrogenation of a precursor under controlled conditions. It belongs to the family of short-chain alkanediols increasingly used in cosmetics as:
Multifunctional Humectant: Attracts and binds water in the stratum corneum, similar to glycerin or propylene glycol but with a lighter skin-feel and less tackiness at equivalent use levels.
Antimicrobial Booster / Co-Preservative: Exhibits mild intrinsic antimicrobial activity against Gram-positive bacteria and some yeasts; more importantly, it synergizes with other preservatives (e.g., sodium benzoate, potassium sorbate, organic acids, or other "free-from" preservatives like ethylhexylglycerin) to lower the minimum inhibitory concentration (MIC) of the primary preservative.
Formulation Aid: Low surface tension assists in wetting and dispersing actives, aiding emulsion stability in O/W or W/O creams and serums.
The HG-N variant typically denotes a cosmetic-grade specification with tighter impurity control for leave-on applications.
How It Supports "Reduced-Preservative" Formulation
1,2-Hexanediol is not usually registered as a standalone preservative (except in very low-water-activity systems like anhydrous serums or oil-based products). Its value in preservation comes from synergy:
Scenario | Role of AscendPro® HG |
|---|
Sensitive-skin / baby care lines | Allows formulators to reduce phenoxyethanol or other harsher preservatives to lower, better-tolerated levels while maintaining challenge-test pass (ISO 11930 / USP <51>) |
"Free-from" marketing (paraben-free, formaldehyde-free) | Fits preservative-boost systems based on benzoic/sorbic acid salts + 1,2-hexanediol |
Low-water-activity serums / ampoules (≤ 15% aq.) | In some regional frameworks may serve as sole preservative if water activity (a_w) and packaging (single-dose / airless) support it—verify with challenge testing |
Spritz / mist products with organic acid preservative | Enhances efficacy of potassium sorbate / sodium benzoate in acidic pH formulas |
Key Performance Benefits Beyond Preservation
1. Humectancy with Light Sensory Profile
Unlike glycerin (which can feel heavy or sticky > 3–5%), 1,2-hexanediol at 0.5–2.0% use level contributes moisturization without tack. It is often blended with glycerin or butylene glycol to optimize cost/feel.
2. Low Surface Tension → Better Wetting
Helps incorporate poorly wetting actives (plant extracts, lipid-soluble vitamins) into aqueous phases, improving homogeneity in clear serums and toners.
3. Good Compatibility & Stability
Stable across pH 3–8 (typical cosmetic range), compatible with anionic/cationic/non-ionic surfactants, and does not discolor or hydrolyze under normal storage. Cold-processable or add-at-cool-down (< 40°C recommended to avoid volatilization of more volatile co-solvents).
4. Regulatory Acceptance
INCI: 1,2-Hexanediol
REACH / TSCA / IECSC listed
China IECIC 2021 compliant (Catalog No. 2287)
Kosher / Halal available on request
Typically approved for use up to 2–3% in most global cosmetic regs (higher in some regions for humectant function only—check local limits)
Typical Use Levels & Incorporation Tips
Application Type | Recommended Use Level | Notes |
|---|
O/W Cream / Lotion (leave-on / rinse-off) | 0.5–2.0% | Add during cool-down phase (below 40°C) to avoid thermal degradation |
Serum / Toner / Essence | 0.5–1.5% | Often combined with ethylhexylglycerin (0.5–1.0%) + preservative |
Anhydrous Oil Serum (very low aq.) | 0.5–1.0% | May serve as sole preservative if a_w low & packaging protective—confirm by challenge test |
Baby / Sensitive Skin Formula | 0.5–1.0% as booster | Allows reduction of primary preservative level |
Always confirm preservative efficacy with a qualified challenge test (ISO 11930/ CTFA / USP <51>) before market launch.
When to Pair with Other Preservation Technologies
AscendPro® HG works best as part of a holistic preservation strategy:
With Organic Acids: Sodium benzoate + potassium sorbate + 1,2-hexanediol → effective at pH ≤ 5.5.
With Ethylhexylglycerin: Common "preservative-booster duo" in modern "mild preservative" systems.
With Traditional Broad-Spectrum Preservatives: Allows downward adjustment of phenoxyethanol or other actives to reduce irritation potential.
Sourcing Considerations for B2B Buyers
When procuring AscendPro® HG / HG-N (1,2-Hexanediol Cosmetic Grade):
✅ Request CoA with assay ≥ 99.0%, residual solvent & heavy metal limits.
✅ Confirm INCI declaration and regulatory dossier (REACH, IECIC, etc.).
✅ Ask about MOQ, lead time, and sample availability for pilot batches.
✅ Inquire re: HG-N vs HG difference (typically tighter spec for leave-on / sensitive application).
✅ Check compatibility data sheets if co-processing with specific preservative blends.
Conclusion: A Multifunctional Ingredient Worth Formulating With
The AscendPro® HG / HG-N (1,2-Hexanediol) is more than a humectant—it is a formulation enabler for modern "clean beauty" preservation strategies. By boosting the efficacy of primary preservatives, it allows formulators to lower levels of harsher actives, maintain robust microbial control, and deliver a light, non-tacky moisturizing feel. For skincare, suncare, and personal care brands targeting sensitive-skin claims or reduced-preservative positioning, 1,2-hexanediol is a well-established, regulator-approved tool in the formulator's toolkit.