Use of Phenoxyethanol SA in Anhydrous Body Scrubs

Yes, Phenoxyethanol SA (eq. Optiphen Plus) can be used in an anhydrous (water-free) body scrub, but there are some important considerations for its effectiveness:

1. Purpose in Anhydrous Products

While anhydrous products do not naturally support microbial growth, body scrubs are frequently used in the shower where water is likely to be introduced into the container. Adding a preservative like Phenoxyethanol SA acts as "insurance" to protect the product from mold and bacteria once water contamination occurs.

2. Solubility and Mixing

• Oil Solubility: Phenoxyethanol SA has limited solubility in pure oils (approximately 0.6% in mineral oil). Since the recommended usage rate for open containers like scrub jars is around 1.25%, you may find it difficult to fully dissolve if the scrub is purely oil-based without any surfactants or emulsifiers.
• Mixing: It should be added during the final stage of formulation when the temperature is below 60°C.

3. pH Considerations

Phenoxyethanol SA contains Sorbic Acid, which requires a pH of 6.0 or lower to be effective. In a water-free scrub, "pH" cannot be measured. However, if water enters the jar during use, the Sorbic Acid will only provide effective protection if the resulting environment stays within the pH 2.0–6.0 range.

Recommendation for Body Scrubs:

If your scrub contains an emulsifier (a "polysorbate" or "emulsifying wax" that allows the oil to turn milky and rinse off easily), Phenoxyethanol SA will incorporate much more easily. If it is a simple oil-and-salt/sugar scrub, ensure you stir it thoroughly to disperse the preservative as evenly as possible.

Usage Rate: 1.0% - 1.25% is recommended for products in open jars.