Other ingredients commonly found in shampoos that are known allergens are aloe, vitamins and botanical extracts. Gluck often suggests people try baby shampoos because they are less likely to contain irritants. Identifying the cause of an allergic reaction from a cosmetic is tricky because more than 5,000 ingredients are used by the cosmetics industry, and unlike drugs, ingredients in cosmetics don't have to be approved by the Food and Drug Administration before they are marketed. The manufacturer is responsible for the safety of its product. However, if a safety problem arises after a cosmetic has been marketed, the FDA can take action to obtain the manufacturer's safety data on the product.
Federal regulations require ingredients to be listed in the order of greatest quantity.
However, that may be of little help if the list is made up of trade names instead of the common name. For example, you may avoid a product that lists Vitamin E as an ingredient, but purchase one that lists tocopherol, which is the same thing. If you need to find out what an ingredient with a trade name is actually made of, check with the manufacturer. The address or phone number should be included on the container or packaging. The CTFA also publishes the expensive International Cosmetic Ingredient Dictionary and Handbook, which cross-references thousands of chemical and trade names.