Fragrances are classified by the amount of essential oil they contain. Prepared personal fragrances fall into four basic categories based on their strength and staying powder. The more essential oil in a prepared mixture, the stronger and more long lasting it will be.
- Perfume -- These are the most long lasting fragrance mixtures. They're about three parts alcohol to one part, or slightly less, essential oils and other fragrance essences.
- Eau de parfum -- With 15 to 20 percent essential oil content, this fragrance mixture is somewhat less potent than perfume. An eau de parfum product will dissipate more quickly than an equal amount of perfume.
- Eau de toilette -- Less concentrated than eau de parfum, eau de toilette contains from 4 to 8 percent essential oil.
- Cologne (or eau de cologne) -- This is the least potent fragrance preparation with about 3 to 4 percent essential oil.
When you're buying individual essential oils to make your own signature scents or cosmetic mixtures, the rules are a little different. Essential oils are usually sold as pure essences. They're designed to be used as ingredients in other preparations, so they're very concentrated. In fact, undiluted essential oils are so intense they can cause lightheadedness, respiratory problems and skin irritation when handled improperly.
Essential oils may also vary based on their intended application. Pharmaceutical grade oils are designed for use in cosmetics and in aromatherapy. They're typically the purest essential oils on the market. Next in line are food grade essential oils produced for cookery applications. Oils in both these categories should be free of harmful ingredients and consistent with their labeling.
Should is the operative word. Fragrance oils aren't as tightly regulated as many other products on the market. A few fall under the U.S. Food and Drug Administration's Dietary Supplement Health and Education Act, but most do not. Because fragrance formulas are so secret, manufacturers aren't required to list individual scent ingredients, and the fragrance industry is largely self-policing when it comes to product purity and choosing ingredients that are safe for consumers.
When choosing essential oils, a good rule of thumb is that a quality oil will probably cost more than a pretender. Buy from a reputable source, and select manufacturers whose products you've used before and who you trust based on experience. You should always use new oils sparingly until you know they will perform to your expectations and not cause skin irritations, headaches or respiratory problems.