Test concentrations and vehicles for dermatological testing of cosmetic ingredients.

In the past, identification of the ingredients responsible for cosmetic allergic reactions was hampered by the difficulty of obtaining ingredient information for individual marketed cosmetic products, as of December 1980. Although some cosmetic companies provided ingredient information for their products, most required that an individual letter be written for each product. Since 1978, the U.S. regulations have required that all ingredients, except components of flavours and fragrances be declared on cosmetic product labels.