Gel Mask Formulation for Face and Lips: Preservative Causing Tingling Sensation

Based on your formula and the tingling sensation experienced on your lips, the most likely cause is the preservative system you are currently using, Phenoxyethanol SA (equivalent to Optiphen Plus). This preservative contains Phenoxyethanol, Caprylyl Glycol, and Sorbic Acid, which can sometimes cause irritation or a warming/tingling sensation, especially on sensitive areas like the lips.

Regarding your question about "Global Globe" and pH compatibility, you are likely referring to Global Guard™ 221. This preservative has a working pH range of 2-7. If your formula's pH is 5.5 or below, Global Guard™ 221 would be compatible with your formula's pH requirements.

Looking at the other ingredients in your formula (4D Hyaluronic Acid, Butylene Glycol, Panthenol powder, Glycerin, Xanthan Gum, Dipotassium Glycyrrhizate), they are generally considered mild and are less likely to cause a tingling sensation at the concentrations you are using. Dipotassium Glycyrrhizate is actually known for its soothing properties, although in very high concentrations, any active ingredient could potentially cause a sensation. However, at 0.1%, it is unlikely to be the cause of tingling.

To address the tingling issue and find a preservative suitable for use on both the face and lips, you should consider milder alternatives to Phenoxyethanol SA. Here are a few options that are compatible with a water-based formula and generally considered gentler:

• NaturePreserve™ Ultra (Gluconolactone & Sodium Benzoate): This is a natural preservative blend that is typically very mild. It works in a pH range of 3-6, which fits your requirement of a pH not exceeding 5.5. It is used at a rate of 0.75-2.0%.
• Preserve-BSB™ (Benzyl Alcohol, Sodium Benzoate, Potassium Sorbate): This preservative blend is also suitable for natural formulations and has a pH range of 2-5.5, fitting your requirement. It is used at a rate of 0.3-1.0%. While it contains Benzyl Alcohol and Potassium Sorbate, it is often perceived as milder than systems containing Phenoxyethanol and Sorbic Acid.
• Global Guard™ 221 (Dehydroacetic Acid & Benzyl Alcohol & Water): As discussed, this preservative works in a pH range of 2-7 and is compatible with your pH requirement. It is used at a rate of 0.5-1.1%. It contains Benzyl Alcohol, which can occasionally cause sensitivity in some individuals, but it is another potential alternative.
• NaturePreserve™ LB2 (Dehydroacetic Acid & Benzoic Acid & Benzyl Alcohol & Water): Similar to Global Guard™ 221, this is a natural origin preservative effective at low pH (2.0-6.5) and used at 0.5-1.0%. It also contains Benzyl Alcohol.
• PaeoniaPreserve™ (Natural Preservative): This natural preservative from Peony root extract can be used at 0.5-2.0% and is soluble in water. It is generally considered mild.

When switching preservatives, it is crucial to perform a challenge test on your final formula to ensure the chosen preservative system is effective against microbial growth in your specific product.

In summary, the tingling is most likely from your current preservative. Consider replacing Phenoxyethanol SA with a milder alternative like NaturePreserve™ Ultra or Preserve-BSB™ for a lip-safe formula. Global Guard™ 221 is compatible with your pH requirements.