Recommended Percentages for Mild Preservatives and Cleansing Agents in Herbal Shampoo

When formulating a herbal shampoo, the appropriate percentage for preservatives and cleansing agents depends on the specific ingredients you choose. However, I can provide general guidance based on common mild options.

Mild Preservatives

For mild or natural-focused preservatives, the typical usage rate is often in the range of 0.5% to 2.0%. Some specific products may have recommendations slightly outside this range, sometimes up to 4.0% depending on their composition and efficacy.

Examples of mild preservatives and their typical ranges include:

• NaturePreserve™ Ultra: Recommended at 0.75-2.0% (often 1.25% for general products).
• Mild Preserved Eco™: Recommended at 0.5-2.0% (often 1.0-1.5% for general cosmetics).
• Global Guard™ 221: Recommended at 0.5-1.1%.

It is crucial to follow the manufacturer's recommended usage rate for the specific preservative you select and to perform challenge testing on your final formulation to ensure adequate preservation.

Very Mild Cleansing Agents (Surfactants)

For very mild cleansing agents suitable for shampoo, especially in a gentle herbal formula, you would typically use a blend of surfactants. The total concentration of surfactants in a shampoo can vary widely, but for a mild formula, it might range from 10% to 25% or more depending on the desired lather and cleaning performance.

Individual mild surfactants often have broader usage ranges, but when used as part of a blend in a mild shampoo, they might be included at lower percentages. Examples of very mild cleansing agents include:

• Mild-Wash L™ (Sodium Lauroamphoacetate) and Mild-Wash C™ (Sodium Cocoamphoacetate): Can be used at 1-20%, with recommendations around 5-10% when used alone or 3-5% when combined with other surfactants.
• Sodium Cocoyl Glycinate and Potassium Myristoyl Glutamate / Potassium Cocoyl Glycinate: These amino acid-derived surfactants are very mild and can be used in ranges like 5-40% or 5-30%, depending on the specific product and desired effect.

For a very mild shampoo, you would likely use a combination of these or similar mild surfactants to achieve effective cleaning without causing irritation.

Calculating for 500ml

To calculate the amount for a 500ml batch, you would convert the percentage to grams (assuming the density is close to 1 g/ml, which is a reasonable approximation for water-based products). For example:

• If you use a preservative at 1.0%, you would need 500ml * 1.0% = 5ml (or approximately 5g).
• If your total surfactant blend is 15%, you would need 500ml * 15% = 75ml (or approximately 75g) of the surfactant blend.

Remember that these are general guidelines. Always refer to the specific product's documentation for precise usage rates and formulation considerations. Performing stability and microbial challenge testing is essential before finalizing and distributing your product.