Water is a natural solvent that dissolves many substances like salt into it. Unfortunately, not all substances dissolve in water, including oils. Fragrance oil is an oil found in many personal care products that contain water. Yet these products containing both ingredients have a uniform texture.
Fragrance oil can be 100 percent synthetic or contain up to 80 percent essential oil mixed with a carrier oil (an oil that dilutes essential oils). According to Teach Soap, fragrance oils are predominantly artificial or synthetic.
Alcohol is the most common solvent used to dissolve fragrance oil into water. Emulsifiers, ingredients that bind oil to water, help dissolve fragrance oils into water and are used in creamy textured products.
Specially denatured alcohol (SD alcohol) is the most common alcohol used to dissolve fragrance oil into water. Arizona Natural Resources lists lecithin, sodium laureth sulfate, sodium lauryl sulfate, cetyl alcohol and polysorbate as common emulsifiers.
SD alcohol is used to make the cheaper watered-down fragrances of eau de cologne and eau de toilette. Cetyl alcohol, sodium laureth sulfate and polysorbate are used to dissolve fragrance oil into water for creams, lotions, shampoos, conditioners and body washes.
Emulsifiers dissolve fragrance oil into water to prevent the two from separating, making it unnecessary to shake up a product like shampoo before each use. Consumers can enjoy cheaper versions of expensive perfumes, eau de cologne and eau de toilette, since alcohol dissolves the fragrance oil into water, creating a less concentrated fragrance.
References and ResourcesCosmetics At Home: Emulsifiers and Their Differences
Arizona Natural Resources: Glossary of Terms