Selecting a Preservative for Kaffir Lime Hair Cream

Hello! I understand you are making a hair cream from kaffir lime pulp and want to extend its shelf life.

As the staff previously informed you, Rosemary Extract functions as an Antioxidant, which helps prevent oils from going rancid. However, it does not prevent the growth of microorganisms such as bacteria, fungi, and yeast, which are the main causes of spoilage in natural products, especially those with high water and moisture content like kaffir lime pulp, and when exposed to the environment.

Therefore, to prevent your hair cream from spoiling and to ensure it is safe to use, you need to include a Preservative.

Regarding the question about the amount to use per 1000cc, preservatives are calculated as a percentage of the total weight of the formula, not directly by volume (unless you know the density of your cream and can convert volume to weight). You should weigh the total amount of your cream and calculate the amount of preservative based on the recommended percentage.

Based on the search, there are several interesting preservative options for cosmetic products, considering your mention of potential exposure to some heat and sunlight (although avoiding these conditions is recommended for maximum product life) and the natural nature of kaffir lime. I would like to suggest a few options:

• Global Guard™ 221: This is a natural preservative, highly water-soluble, broad-spectrum, and works well in a wide pH range from 2-7, making it suitable for acidic products like kaffir lime. The recommended usage rate is 0.5-1.1% of the total formula weight. Caution: It should be added when the product temperature is below 45°C.
• NaturePreserve™ LB2: Also a natural preservative, highly water-soluble, highly effective against bacteria and fungi at low pH. It works well in the pH range of 2.0-6.5. The recommended usage rate is 0.5-1.0% of the total formula weight. Avoid heat above 50°C during mixing.
• Mild Preserved™ COS: This is a broad-spectrum preservative, highly water-soluble, works in a very wide pH range of 2-8, and is odorless. The recommended usage rate is 0.75-1.5% of the total formula weight. It should be added when the product temperature is below 45°C.

The most suitable preservative depends on the final pH value of your kaffir lime hair cream. You should measure the pH of your finished product and choose a preservative that works effectively within that pH range.

Regarding shelf life, if a suitable preservative is used at the correct concentration for the formula, and manufacturing and packaging are done cleanly, cosmetic products generally have a shelf life of about 1-2 years unopened and around 6 months to 1 year after opening. However, storage under unsuitable conditions, such as high heat or direct sunlight, will significantly shorten the product's life, even with a preservative. It is recommended to store the product in a cool place away from direct sunlight.

Most importantly, you must perform a Challenge Test after adding the preservative to your formula to confirm that the preservative you chose, at the concentration you used, is effective enough to prevent microbial growth in your specific formula before using or selling it.