Fragrance is a pleasant-smelling liquid that people put on their bodies to make themselves smell good. People can also use scents in cleaning products to give them a fresher, cleaner smell. Fragrance ingredients are in many of the personal care and household products we use every day, including shampoo, hand soap, cologne, body spray and deodorant. They’re even in household cleaners, laundry detergents, dryer sheets and room air fresheners.
Perfume and scented lotions are generally made with a mix of more than 3,500 chemicals that give the fragrance their unique smell. The majority of these chemicals are synthetic and can cause a range of health problems, from skin irritation to asthma and reproductive disorders. Manufacturers aren’t required to list these chemicals on the product labels because they’re considered trade secrets. That’s why it’s important to look for products labeled “fragrance,” “parfum” or “aroma.” Products that are free from fragrance chemicals of concern are marked EWG VERIFIED.
The fragrance industry uses many scientific methods to test and develop perfumes. These include hazard identification and dose-response assessment, which determine how much of an ingredient is needed to create an adverse reaction on the skin. Other tests can measure how quickly a perfume dissipates, and how long its scent lasts. In the United States, the federal Consumer Product Safety Commission (CPSC) regulates the testing of cosmetic and fragrance ingredients. The International Fragrance Association and the Research Institute for Fragrance Materials also set standards for fragrance testing.
A perfume’s fragrance is determined by its top, middle and base notes. Top notes are typically bright, fruity or citrusy. Middle notes add depth and character. And base notes linger on the skin, lasting more than 24 hours after application. Perfumers construct perfumes using a mix of raw materials such as essential oils, extracts and synthetic aroma chemicals. They then evaluate the composition on paper blotters called mouillettes and may adjust it accordingly.
The perfumer must take into account the environmental and personal preferences of a potential customer when creating the fragrance. This process can be as simple as adding a little bit of lemon zest to a rose fragrance or as complex as recreating the scent of a specific flower with different growing techniques, extraction methods and dilutions.
Some scents, such as rose, jasmine and narcissus are grown specifically to be used in perfume, with specialized farming practices and equipment. They’re often grown in large fields where the plants are exposed to sunlight and natural airflow, which helps them to develop a more intense fragrance. This makes roses and narcissus among the most valuable perfume raw materials.
Most other scents are created through synthesis, which involves adding several aroma chemicals together to create the desired fragrance. Some of these chemicals are derived from natural sources, such as plant sterols and esters, while others are synthetic, such as musk ketone, hedione and eugenol. Perfumers also experiment with natural raw materials by combining them with other compounds such as tannins and fatty acids.