What is the difference between a fragrance and a masking fragrance?
Fragrances and masking fragrances are one in the same, but have a different purpose. Fragrances are designed to create a perceivable pleasant smell while masking fragrances are designed to mask a bad smell creating a neutral smell. Some commonly used raw materials have a foul odor that must be covered to increase consumer acceptability. Examples include the odor of ammonium thioglycolate, accounting for the rotten egg smell of permanent hair waving solutions, which requires a masking fragrance to allow the consumer to sit with the solution on the hair. Another example is the quaternized nitrogen compounds, also known as quats, commonly found in hair conditioners. These require some type of masking fragrance. Even some surfactants used to cleanse the skin and hair require a masking fragrance for consumer acceptance.
The goal of a masking fragrance is to give the perception that the product is unscented. Thus, unscented does not mean fragrance-free, but rather smell-free. However, most products are deliberately scented to imply certain aspects of their functionality. For example, consumers believe that citrus fragranced household cleansers work better than unscented cleansers. Dandruff shampoos that have a menthol medicinal smell are thought to alleviate itch better than unscented shampoos. Fragrance can also be used to imply the presence of an ingredient, such as a product containing strawberry extract can be fragranced like strawberries. The fact remains that consumers believe products work better with certain scents! This places tremendous importance on the very primitive olfactory center of the brain.