Cleanser Color Change: Why did my clear cleanser turn yellow?

Question

I made a clear cleanser with the following ingredients:

Sulfate Free Shampoo Base 20%
HyaCoat 0.1%
MOIST24 5%
Disodium EDTA 0.2%
Phenoxyethanol SA 1%
Salt 1%
Distilled water q.s.

After mixing, the cleanser was clear. However, after using it for about a month, it turned yellow. I would like to know which active ingredient is likely causing this color change.

MySkinRecipes Expert · Accepted Answer

Cleanser Color Change Analysis

Based on the ingredients in your cleanser formulation, the most likely cause for the product changing from clear to yellow after about a month is the Phenoxyethanol SA (eq. Optiphen Plus).

The description for Phenoxyethanol SA indicates that it "may appear darker in color when it lasts longer or exposed to light for a long time." This property aligns with the observed yellowing of your cleanser over time.

Other ingredients like Disodium EDTA are described as white to light yellow powder, which could contribute some initial color, but the progressive change to yellow suggests a component that degrades or oxidizes over time, with Phenoxyethanol SA being the most probable candidate among your listed ingredients based on the product information.

Ensuring the product is stored away from direct sunlight and heat can help minimize this color change.