Preservative for Facial Spray: Eye Gentleness & Moisturizing

Based on your requirements for a facial spray preservative that is gentle on the eyes, provides moisture, and considering both synthetic and natural options, here is a comparison and recommendation:

Mild Preserved Eco™ (Ethylhexylglycerin, 1,3 Propanediol) is a gentle option that is not classified as a preservative by the FDA, allowing for "preservative-free" claims. Its description highlights that it does not irritate the skin and acts as a humectant, helping to retain moisture. This aligns with your desire for moisturizing properties. While not specifically tested for eye irritation like Eye Preserved™, its general gentleness suggests it is less likely to cause irritation compared to harsher preservatives. Note that Mild Preserved Eco™ contains Ethylhexylglycerin and Propanediol, not Caprylyl Glycol as you initially mentioned. Ethylhexylglycerin itself is also described as a gentle humectant.

Eye Preserved™ (Polyhexamethylene Biguanide, PHMB) was developed for use in contact lens cleaners and is specifically noted as suitable for formulations used around the eyes or for sensitive skin, indicating a low potential for eye irritation. However, its description does not mention any moisturizing benefits. It also has compatibility issues with anionic ingredients like Hyaluronic Acid and Xanthan Gum, which are common in water-based facial sprays.

For natural options that provide moisturizing benefits, Probio-Protect™ (Lactobacillus Ferment Preservative) is a strong candidate. It is a natural preservative derived from the fermentation of Lactobacillus and is noted for its ability to moisturize the skin by reducing transepidermal water loss (TEWL). It is water-soluble and can be used in a facial spray formula. While its description doesn't explicitly state "non-irritating to eyes," its natural origin and moisturizing property make it a gentle option worth considering. Other natural preservatives like NaturePreserve™ Ultra or Coco-Preserve™ are effective but do not specifically mention moisturizing benefits.

Recommendation:

If your priority is a gentle preservative that also provides moisturizing benefits, and you are open to a synthetic option that allows for a "preservative-free" claim, Mild Preserved Eco™ is a suitable choice. Its humectant properties directly address your need for the spray to help moisturize the skin.

If a natural preservative is strongly preferred and moisturizing is still important, Probio-Protect™ is recommended due to its natural origin and proven ability to reduce TEWL, thus providing a moisturizing effect.

If extreme gentleness specifically for the eye area is the absolute highest priority above all else, and moisturizing is less critical, Eye Preserved™ could be considered, but be mindful of its incompatibility with certain ingredients and lack of moisturizing properties.

Regardless of the preservative chosen, it is crucial to perform a challenge test on your final facial spray formula to ensure its effectiveness and safety.