Analysis of Your Night Cream Formula and Potential Causes of Rash

It's great that you achieved a nice texture with your night cream formula! It's frustrating when some users experience adverse reactions, even with careful preparation. Based on your formula and process, here's an analysis of potential causes for the rash, besides individual allergies:

Potential Irritants in the Formula

While your formula contains many beneficial ingredients for skin repair and hydration, such as Ceramide Complex, Double Hyaluron Liquid, Allantoin, Centella Extract, and various oils, some ingredients are more likely to cause irritation, especially on sensitive skin:

• Phenoxyethanol: This is a preservative used to prevent microbial growth. While generally considered safe at recommended levels, some individuals can be sensitive to it. Your formula uses 0.5%, which is within the typical range, but even this concentration can cause a reaction in some people. The previous staff reply also highlighted this as a possibility.
• Fragrance: Fragrances are a very common cause of skin irritation and allergic reactions in cosmetic products. Even a small amount (0.1% in your formula) can be problematic for sensitive individuals. For a night cream focused on skin recovery, removing fragrance is often recommended to minimize potential irritation.
• Pumpkin Renew: This ingredient acts as a gentle exfoliant. While milder than traditional AHAs, any exfoliating ingredient can potentially cause some initial redness or sensitivity, especially on compromised or sensitive skin. The concentration of 1.5% is within the recommended range for daily use, but it's still a possibility for reactive skin.

Other ingredients like oils, humectants (MOIST24, 1,2-Hexanediol), emulsifiers (Cetearyl Alcohol, Milk Lotion Maker, Luxury Cream Maker), and peptides (Argireline, Pep-Coll) are generally less likely to cause irritation at the concentrations used, but individual sensitivities can occur with any ingredient.

Manufacturing Process Considerations

Your cleaning process is generally good for a home setting. Using gloves, washing equipment, and using purified water are all correct steps. Regarding the alcohol sterilization:

• Alcohol Drying: It is best to let the alcohol air dry completely on equipment and containers rather than wiping it with tissue. Wiping can reintroduce microbes or fibers from the tissue, compromising the sterilization.
• Weighing Small Amounts: As the previous staff reply mentioned, accurately weighing very small amounts (like 0.5% Phenoxyethanol or 0.1% Fragrance) can be challenging with standard scales. Over-measuring these potentially irritating ingredients, even slightly, could increase the risk of reaction.

Suggestions for Modification

To reduce the likelihood of irritation for sensitive users, you could consider the following modifications:

• Reduce or Replace Phenoxyethanol: As suggested by the staff, try reducing Phenoxyethanol to 0.1-0.2%. Alternatively, consider using Phenoxyethanol SA, which is a broad-spectrum preservative blend that might be less irritating or allow for a lower total preservative concentration while maintaining efficacy.
• Remove Fragrance: Eliminate the Fragrance from the formula entirely. This is one of the most common culprits for skin reactions.
• Adjust Pumpkin Renew: If you suspect Pumpkin Renew, you could try reducing its concentration or temporarily removing it to see if the reaction improves. However, given its gentle nature and low concentration, this might be less likely than the preservative or fragrance.

Performing patch tests on individuals with sensitive skin using variations of the formula (e.g., one without fragrance, one with reduced Phenoxyethanol) could help pinpoint the exact cause of the reaction.

Relevant Ingredients Mentioned

• Purified Water
• Disodium EDTA
• Allantoin
• Ceramide Complex
• Double Hyaluron Liquid
• Pumpkin Renew
• MOIST24
• 1,2-Hexanediol
• Phenoxyethanol
• Fractionated Coconut Oil
• Jojoba Oil
• Olive CLEAR
• Cetearyl Alcohol
• Milk Lotion Maker
• Luxury Cream Maker
• Centella Extract
• Vitamin E
• Argireline
• Pep-Coll
• Phenoxyethanol SA (as an alternative preservative)