Many Consumers believe that natural ingredients are better for the skin than synthetic ingredients (or chemical ingredients).
Even when it's essentially the same chemical element, buyers have a persistent prejudice against synthetic ingredients. For example, many regard Casein (milk protein) as a beneficial additive while classifying Sodium Caseinate as a harmful synthetic. Also, they view Glutamic Acid as a useful amino acid while dismissing Sodium Glutamate as a chemical seasoning to be avoided. If I may suggest the conclusion here, this perception regarding natural vs. synthetic ingredients isn't entirely correct.
In most cases, natural ingredients in fragrance are derived from essential oils.
Cosmetic experts say that natural ingredients can lead to more allergic reactions than synthetic ones because synthetic ingredients go through a refining process to minimize allergic reactions. Natural ingredients do not.
Natural fragrances are considered safe, not because they contain no harmful ingredients, but the amount of those ingredients is negligible for one's health. In contrast, any use of toxic ingredients is prohibited in the manufacturing process of synthetic fragrances.
For example, one of the most popular essential oils, Lavender oil, has a Green EWG rating, but it can also lower blood pressure so Lavender oil (that hasn't been sufficiently diluted) should be used with caution by pregnant women and those with low blood pressure. Also, oils in the Citrus family can trigger sun allergies for some, so daytime use should be avoided by those individuals.
Other drawbacks of natural fragrances are that it is difficult to concoct a wide variety of scents and that the scent changes with the passage of time.
One can not extract scents from all vegetation, so there is a limit to the spectrum of naturally derived scents. For example, one can not extract essential oils from such fruits as mango, apple, banana, pineapple, peach, strawberry, etc.
Moreover, when compared in equal quantities, natural fragrances' scents are generally weaker and fade more quickly than those from synthetic fragrances.
Of course, natural ingredients have many pluses but the common belief that natural ingredients are always safer than chemical ones is simply not true.