Optiphen Plus is a premium broad-spectrum cosmetic preservative — one of the most trusted and widely used paraben-free, formaldehyde-free preservative systems available to Australian cosmetic formulators. A clear to pale yellow liquid blend of Phenoxyethanol, Caprylyl Glycol, and Sorbic Acid, it delivers reliable antimicrobial and antifungal protection across a wide range of personal care products including shampoos, conditioners, facial cleansers, body washes, creams, lotions, gels, and toners.

Preserving water-containing cosmetic formulations is not optional — it is a safety and regulatory requirement. Any formulation containing water (including hydrosols, aloe vera juice, and other aqueous ingredients) is susceptible to microbial contamination from bacteria, yeast, and mould. Contaminated cosmetics can cause serious skin infections, eye infections, and other health hazards. Optiphen Plus provides the broad-spectrum protection required to keep your water-containing formulations safe throughout their intended shelf life.

Optiphen Plus is particularly well suited to the growing Australian natural and clean beauty market. It contains no parabens, no formaldehyde, and no formaldehyde-releasing preservatives — meeting the requirements of most natural and clean beauty certification standards and consumer expectations. It is one of the most effective single-component preservative systems available at recommended usage rates.

The critical formulation note for Optiphen Plus: it performs optimally at pH 6.0 or below. Its sorbic acid component is only effective as an antifungal at acidic pH levels — above pH 6.0, sorbic acid's preservative efficacy drops significantly. Always check and adjust your formulation pH before and after adding Optiphen Plus, and use a calibrated pH meter for accurate measurement.

HOW IT WORKS — THE THREE-COMPONENT SYSTEM

Optiphen Plus achieves broad-spectrum protection through three complementary active components working synergistically:

Phenoxyethanol (the primary antibacterial) Phenoxyethanol is a glycol ether with strong bactericidal activity. It disrupts bacterial cell membranes, preventing growth and killing existing bacteria. It is effective against a broad range of gram-positive and gram-negative bacteria including Staphylococcus aureus and Pseudomonas aeruginosa — two of the most common and serious cosmetic contaminants. Phenoxyethanol's activity is relatively pH-independent, providing reliable antibacterial protection across a wide formulation range.

Caprylyl Glycol (the booster and skin conditioning agent) Caprylyl Glycol is a multifunctional ingredient — it acts as both a preservative booster and a cosmetic emollient. As a preservative booster, it enhances the activity of phenoxyethanol and sorbic acid through membrane disruption effects and by disrupting microbial cell function. As a skin conditioning agent, it contributes a smooth, non-greasy skin feel — making it a beneficial addition beyond its preservative function. It also has some antifungal activity in its own right.

Sorbic Acid (the antifungal) Sorbic acid is a naturally occurring organic acid (found in berries of the Sorbus aucuparia tree) with proven antifungal and anti-yeast activity. It works by inhibiting fungal enzyme systems involved in energy metabolism. Critically, sorbic acid is only active in its undissociated (protonated) form, which only occurs at pH below 6.0. Above pH 6.0 (particularly above pH 6.5), sorbic acid becomes largely dissociated and loses most of its antifungal efficacy. This is the defining constraint of Optiphen Plus — it must be used in formulations at pH 6.0 or below to achieve the full broad-spectrum claim.

The result: Phenoxyethanol handles bacteria; sorbic acid handles yeast and mould; caprylyl glycol boosts both and contributes skin feel. Together at 0.75–1.5%, they provide comprehensive broad-spectrum protection sufficient for most cosmetic formulation applications.

USAGE RATES BY FORMULATION TYPE

Face and body lotions and creams (O/W emulsions)

Rate: 1.0–1.2%
pH requirement: Adjust to 5.0–5.5 for optimal skin compatibility and preservative efficacy
Notes: The most common application; full broad-spectrum protection at 1% in well-formulated pH 5.0–5.5 lotions

Facial serums and toners (water-based)

Rate: 0.75–1.0%
pH requirement: 4.5–5.5 typical for serums; ideal for sorbic acid activity
Notes: Ensure complete dispersion — stir thoroughly in aqueous formulations with low emulsifier content

Shampoos and conditioners

Rate: 1.0–1.5%
pH requirement: Shampoos typically pH 5.0–6.0; rinse-off application; upper end of usage rate recommended
Notes: Can be added at any production phase; ensure uniform dispersion throughout

Body washes and facial cleansers

Rate: 1.0–1.2%
pH requirement: 5.0–6.0
Notes: Effective in surfactant-rich formulations; caprylyl glycol aids dispersion

Gels (carbomer, hydroxyethylcellulose, xanthan gum)

Rate: 0.75–1.0%
pH requirement: Note that many carbomer gels are formulated at pH 6.0–7.0 — if your gel must be above pH 6.0, consider alternative preservative systems (e.g., Optiphen, Germaben, or Euxyl PE 9010)
Notes: Stir thoroughly for uniform dispersion in gel systems

Bath and body oils (anhydrous)

Rate: Not required for purely anhydrous formulations — preservatives are only needed where water is present
Notes: If your oil formulation could be contaminated by water during use (e.g., used in the shower), consider preservation at 0.5–0.75%

Baby products

Rate: 0.75–1.0%
pH requirement: 5.5–6.0 for baby skin compatibility
Notes: Optiphen Plus is accepted in most baby product formulations at the lower usage rate; check with your regulatory consultant for specific baby product claims

Eye creams and eye gels

Rate: 0.75–1.0%
Notes: Suitable for periocular formulations at lower usage rates; patch testing essential

Micellar water and makeup remover

Rate: 0.75–1.0%
pH requirement: Adjust to 5.5–6.0

Dry shampoos and anhydrous powders

Rate: Not required — no water present means no microbial growth risk

Preservatives