Disodium EDTA and Rose Hip Oil Smell in Formulations

Here is information regarding your questions about Disodium EDTA and the smell of Rose Hip Oil in your cream formulation.

Disodium EDTA Usage

Based on the information, it is recommended to include Disodium EDTA in your formulations whenever possible, even if you believe the water is clean. While clean water reduces immediate concerns, metal ions from the environment can still dissolve into the water or the formulation over time, especially when stored in open containers. Although this process is slow and involves low concentrations, adding Disodium EDTA helps to chelate (bind) these metal ions, preventing them from interfering with other ingredients and helping to maintain the stability and shelf life of the product. Since the cost of adding Disodium EDTA is minimal, including it is a good practice for formulation stability.

Addressing Rose Hip Oil Smell

The "rancid" smell you are experiencing in your cream is likely the natural scent of the Rose Hip Oil itself, particularly in virgin or extra virgin grades. These natural oils have their own characteristic odors, which can sometimes be strong.

You mentioned adding 0.5% fragrance and being concerned about adding more due to potential skin irritation. This is a valid concern, as high concentrations of fragrance can indeed cause sensitivity for some individuals. Using a fragrance specifically designed for cosmetic formulations is also important.

Here are a few approaches to consider:

• Increase Fragrance (Cautiously): If you choose this route, increase the fragrance level gradually and test for stability and potential irritation. However, as you noted, this might not be ideal for sensitive skin.
• Reduce or Remove Rose Hip Oil: If the natural scent is too strong and cannot be masked, reducing the percentage of Rose Hip Oil or removing it entirely from the formula is the most direct way to eliminate the odor.
• Use Processed Oils or Synthetic Emollients: As mentioned in the forum replies, many commercial formulations use processed oils or synthetic emollients like the LipidSoft range instead of high percentages of natural oils. These alternatives often have little to no odor and are less prone to rancidity, while still providing desired skin feel and benefits. Examples include LipidSoft CC or LipidSoft Lite, which offer different textures and properties without the strong scent of natural oils. While natural oils offer unique benefits, using synthetic alternatives can help overcome odor and stability challenges.
• Expert Fragrance Blending: Masking the natural scent of an oil requires specific knowledge of fragrance blending. Some fragrances are more effective at covering certain types of odors than others. This often requires expertise to achieve successfully without simply overpowering the formula with fragrance.

Ultimately, balancing the benefits of natural oils like Rose Hip Oil with formulation challenges like odor requires careful consideration of your desired product characteristics and target audience.