✦ Paraben-free and formaldehyde-free broad-spectrum preservative system for modern formulations
✦ Protects water-containing products against bacteria, yeast, and mold
✦ Liquid form allows precise dosing and easy cold-phase incorporation
✦ Effective within pH 3.0 to 6.0, covering most acidic and mildly acidic cosmetics
✦ Compatible with a wide range of humectants, emollients, and cosmetic actives
✦ Can be added at cool-down below 40°C, protecting heat-sensitive ingredients
✦ Suitable for both rinse-off and leave-on formulations including emulsions and serums

Optiphen Plus Liquid is a multifunctional preservative blend composed of phenoxyethanol, caprylyl glycol, and sorbic acid. Developed as a paraben-free alternative to older preservation systems, it was formulated to meet the growing consumer and regulatory demand for cleaner cosmetic products without sacrificing microbial safety. It has been widely adopted in the global cosmetics industry since the early 2000s and remains a benchmark broad-spectrum preservative for water-containing formulas.

What makes Optiphen Plus Liquid distinctive is the deliberate synergy of its three active components. Phenoxyethanol provides the primary antibacterial action, caprylyl glycol enhances overall antimicrobial efficacy while contributing a secondary skin-feel benefit, and sorbic acid extends the coverage against yeast and mold. Together they deliver reliable preservation at lower individual concentrations, reducing irritation potential while maintaining robust protection. The liquid format also improves dosing accuracy and reduces dispersion effort compared to solid or semi-solid preservative alternatives.

Bio Shop Pakistan supplies cosmetic-grade Optiphen Plus Liquid suitable for DIY beauty formulators, soap makers, professional cosmetic chemists, and small-batch skincare manufacturers.

INCI Name : Phenoxyethanol (and) Caprylyl Glycol (and) Sorbic Acid
Chemical Name : 2-Phenoxyethanol; 1,2-Octanediol; (2E,4E)-Hexa-2,4-dienoic Acid
CAS Number : 122-99-6 (Phenoxyethanol); 1117-86-8 (Caprylyl Glycol); 110-44-1 (Sorbic Acid)
Molecular Formula : Blend — no single molecular formula applicable
Appearance : Clear to slightly hazy liquid
Odor : Mild, faint characteristic odor
pH (1% solution) : Approximately 4.0 – 5.5 in 1% aqueous solution; verify with supplier
Solubility : Soluble in ethanol and propylene glycol; dispersible in water with mixing
Specific Gravity : 1.03 – 1.06 at 25°C
Flash Point : >100°C
HLB Value : Not Applicable
Recommended Use Level : 0.75% – 1.5%
Type : Broad-spectrum liquid preservative blend (paraben-free, formaldehyde-free)
Shelf Life : 2 years from date of manufacture when stored correctly

Skincare (Creams, Serums, Lotions) ★★★★★
Optiphen Plus Liquid is highly effective in water-containing emulsions and water-based serums that naturally fall within its ideal pH range. Add at 1.0% during the cool-down phase below 40°C for consistent performance.

Haircare (Shampoo, Conditioner, Masks) ★★★★☆
It performs reliably in rinse-off and leave-on hair products when the formula pH is maintained between 4.0 and 5.5. Always verify the final formulation pH before concluding preservation is adequate.

Soap Making (Cold Process, Melt and Pour) ★★☆☆☆
Cold process soap operates at a pH far above 7.0, which renders Optiphen Plus entirely ineffective as a preservative. It is only suitable in melt and pour bases where the pH is controlled within the acceptable acidic range.

Body Care (Scrubs, Butters, Balms) ★★★☆☆
Optiphen Plus is useful in water-containing body scrubs and emulsified body butters but unnecessary in fully anhydrous formulas such as pure oil-based balms. Incorporate at cool-down in any emulsified product to ensure even distribution.

Functional Cosmetics (Deodorants, Sunscreen, Baby Care) ★★★★☆
Well-suited for deodorant emulsions and water-phase sunscreen formulas operating within the effective pH window. Exercise caution in baby care products and do not use in diaper area creams for children under three years of age.

In my formulating practice, Optiphen Plus Liquid is my default go-to for low-pH systems precisely because it requires no neutralization step and can be added directly at cool-down without disrupting emulsion architecture or destabilizing sensitive actives. I reach for it consistently in AHA toners, vitamin C serums, and acidic leave-on conditioners where the naturally low pH works in its favor rather than against it. Its liquid form eliminates the solubilization step required by solid preservatives, which is a genuine time-saver in batch production.

ADVANCED TIP: To extend preservative efficacy in high-water-activity formulations such as hydrogels or essence-style serums, combine Optiphen Plus Liquid at 0.75% with 0.3% to 0.5% ethylhexylglycerin. This pairing broadens the antimicrobial spectrum significantly, allowing you to reduce the Optiphen Plus level without compromising challenge test outcomes. Always validate the final system with a full preservative efficacy test per ISO 11930 before committing to production scale-up.

Normal Skin : ★★★★★ — Well-tolerated at all recommended use levels with no known adverse effects in healthy, uncompromised skin.
Dry Skin : ★★★★☆ — Generally safe and compatible; the caprylyl glycol component provides mild humectant support that benefits dry skin types.
Oily Skin : ★★★★★ — Ideal for the lightweight water-based formulas preferred by oily skin types without adding any occlusive weight.
Combination : ★★★★☆ — Effective across the varied formula types used for combination skin without disrupting skin balance or finish.
Sensitive Skin : ★★★☆☆ — Phenoxyethanol is a recognized mild sensitizer in susceptible individuals; patch testing is strongly recommended before use.
Mature Skin : ★★★★☆ — Compatible with enriched anti-aging formulations and poses no known stability concern with common actives used for mature skin.
Acne-Prone : ★★★★☆ — Non-comedogenic and appropriate for water-based acne-targeted formulas at the lower end of the recommended use range.

CONCEPT 1: Low-pH Vitamin C Brightening Serum
Usage Level : 1.0%
Key Ingredients: L-Ascorbic Acid (15%), Niacinamide (3%), Sodium Hyaluronate, Panthenol
Result : A stable, water-based antioxidant serum with active vitamin C efficacy preserved reliably within the pH 3.0 to 3.5 window required for ascorbic acid stability.

CONCEPT 2: Daily Hydrating Face Lotion
Usage Level : 1.0%
Key Ingredients: Glycerin, Cetearyl Alcohol, Polysorbate 60, Allantoin
Result : A light, fast-absorbing daily moisturizer with clean skin feel and fully validated broad-spectrum preservation across its water phase.

CONCEPT 3: AHA Exfoliating Toner
Usage Level : 0.75%
Key Ingredients: Glycolic Acid (5%), Lactic Acid (3%), Sodium PCA, Panthenol
Result : An effective chemical exfoliating toner preserved within its naturally acidic pH range, suitable for twice-weekly application to promote cell turnover and even skin tone.

INCI Declared : Yes — all three components must be individually declared on the finished product label
EU Cosmetics Reg : Permitted — Phenoxyethanol max 1.0% in final product (Annex V, Entry 29); Sorbic Acid max 0.6% in final product (Annex V, Entry 6); Caprylyl Glycol is not a regulated preservative under EU Annexes
Rinse-Off Limit : No overall blend limit established; phenoxyethanol contribution must not exceed 1.0% in the final product
Leave-On Limit : Phenoxyethanol contribution must not exceed 1.0% in the final finished product under EU Annex V
Allergen Alert : Yes — phenoxyethanol is a known potential sensitizer; patch testing is advised for sensitive skin applications
Skin Safety : Safe at recommended levels of 0.75% to 1.5%; do not formulate above a phenoxyethanol contribution of 1.0% in the finished product
Eye Area Use : Use with caution — suitable for periorbital leave-on products at recommended levels; avoid direct eye contact with undiluted ingredient
Ingestion : Not for internal use
Pregnancy Use : Consult physician — phenoxyethanol is considered low risk at standard cosmetic levels but limited gestational safety data exists
Child Safety : Avoid use in diaper area creams for infants and children under 3 years per SCCS opinion SCCS/1575/16; otherwise suitable in age-appropriate rinse-off products
Ventilation : Not required under normal handling and formulation conditions
Storage : Store in a cool, dry place away from direct sunlight and elevated temperatures; do not refrigerate
Container : HDPE or glass preferred for long-term storage; avoid reactive metals and extended PET contact

⚠️ Phenoxyethanol has been associated with mild sensitization reactions in susceptible individuals. The SCCS confirmed safety at up to 1.0% in finished cosmetic products (SCCS/1575/16) but specifically advises against use in leave-on products applied to the diaper area of children under 3 years. Formulators should confirm the phenoxyethanol contribution at final use level does not exceed 1.0% in the finished formula.

Working pH Range : 3.0 – 6.0 (preservative efficacy declines significantly above pH 6.5 and is not reliable above pH 7.0)
Heat Stability : Stable up to 80°C; add below 40°C to prevent sorbic acid volatilization and maintain blend integrity
Freeze-Thaw Stable : Yes
Emulsion Type : Both O/W and W/O
Emulsification Phase: Cold (add to cool-down phase after primary emulsification is complete)
Compatible With : Glycols, humectants, AHA and BHA actives, botanical extracts, sodium hyaluronate, nonionic and anionic emulsifiers
Incompatible With : High-pH systems above pH 7.0; strong oxidizing agents; high concentrations of cationic quaternary compounds
Oxidation Risk : Low — no antioxidant addition required under standard storage and formulation conditions
Discoloration Risk : Possible — sorbic acid component may contribute slight yellowing over extended storage under heat or high humidity
Formulation Notes : Always measure and confirm final formula pH within 3.0 to 6.0 before finalizing. Add to the cool-down phase only; direct addition to the hot phase risks sorbic acid loss through volatilization and reduces overall preservation efficacy.

Q: What is the recommended usage level of Optiphen Plus Liquid in a leave-on face cream?
A: The standard usage level is 1.0% for most leave-on emulsions. You may reduce to 0.75% in simpler aqueous serums or increase to 1.5% in challenging high-water-activity systems, but always confirm adequacy with a formal preservative efficacy test per ISO 11930.

Q: At what stage of formulation should I add Optiphen Plus Liquid?
A: Add it during the cool-down phase once the temperature has dropped below 40°C. This approach prevents potential sorbic acid loss through heat volatilization and keeps the full preservative blend intact in the finished product.

Q: Will Optiphen Plus Liquid work in cold process soap?
A: No. Cold process saponification raises pH well above 9.0, which is completely outside the effective range of this preservative system. It is only suitable for melt and pour soap bases where pH is controlled to remain below 6.0.

Q: Is Optiphen Plus Liquid safe for use in sensitive skin products?
A: It is safe at recommended levels for most users, but phenoxyethanol is a recognized mild sensitizer in some individuals. For products targeting very sensitive skin, use at the lower end of the range (0.75%) and include a patch test recommendation on the finished product label.

Q: How does Optiphen Plus Liquid compare to Leucidal Liquid as a preservative?
A: Optiphen Plus Liquid provides more reliable and broadly validated broad-spectrum protection compared to Leucidal Liquid, which is a ferment-based system with variable efficacy across product types. Leucidal qualifies as a natural preservative under COSMOS standards, making it preferable for certified natural formulations, while Optiphen Plus is the stronger choice for conventional formulas where full microbial challenge test performance is the priority.