Preventing Mold in Herbal Scrub with Preservatives

It's common for homemade products like herbal scrubs to grow mold if they don't contain a preservative, especially since they contain water and natural ingredients which are prone to microbial growth. Adding a suitable preservative is essential to prevent mold and bacteria, ensuring the product is safe and lasts longer.

Based on the available information, here are a few preservative options suitable for a cosmetic scrub, along with their recommended usage rates:

• Mild Preserved™ COS: This is a broad-spectrum, water-soluble preservative that works in a wide pH range (2-8) and is odorless. It can be added at any step of the formulation process, provided the temperature is below 45°C. The recommended usage rate is 0.75-1.5%.
• Global Guard™ 221: Another water-soluble, broad-spectrum preservative effective against various microbes, including fungi (mold). It works in a pH range of 2-7 and should be added when the product temperature is below 45°C. The usage rate is 0.5-1.1%.
• Preserve-BSB™: This preservative is effective against bacteria, mold, and yeast and is suitable for products with a pH up to 5.5. It dissolves in the water phase. The recommended usage level is 0.3-1.0%, and the temperature during production should be below 80°C.
• NaturePreserve™ LB2: This option is effective against bacteria and fungi (mold) at lower pH values (2.0-6.5). It is water-soluble and should be dissolved in the water portion, avoiding heat above 50°C. The usage rate is 0.5-1.0%.
• NaturePreserve™ Ultra: A natural preservative effective against bacteria, fungi, and yeast. It works in a pH range of 3-6 and is heat tolerant. It's a powder that dissolves in water. The usage rate is 0.75-2.0% (recommended 1.25%).

When choosing a preservative, consider the pH of your scrub formulation, as each preservative has an optimal working range. Also, ensure the preservative is compatible with other ingredients in your scrub.

It is highly recommended to perform a challenge test on your final product formulation to confirm the effectiveness of the chosen preservative at the selected concentration under real-world conditions before widespread use or sale.