Consumer exposure to fragrance ingredients: providing estimates for safety evaluation

To fully apply already published procedures for the safety evaluation of fragrance ingredients, it is necessary to estimate exposure through different routes and leading to different potential endpoints. Worst-case scenario calculations indicate that deposition on the surface of the skin following use of cosmetics represents the major route of exposure to fragrance ingredients when conservative estimates for evaporation, rinsing, and other forms of product removal are employed. Hydroalcoholic perfumes and colognes deliver the highest dose after single product use. Surveys of formulas used in this type of product allow the calculation of average maximum or upper 97.5th percentile concentration of the ingredient in formulas. With this type of exaggeration, the use of estimates of "typical" cosmetic use can be maximized to take account of excessive consumption patterns for both short-term and long-term exposure estimates. In the latter case, multiple product use must be considered. Short-term exposure (single product doses) of an ingredient found at an average maximum use level of P% in fragrances is taken to be 0.2 x P% or 3P microg/cm(2). Using upper 97.5th percentile concentrations (P(97.5)) of individual ingredients in fragrances, the long-term exposure is taken to be P(97.5) x 2,547 microg/kg body wt/day. The estimates of long-term exposure incorporate a number of highly conservative assumptions (e.g., over a long period, every product used will contain a fragrance with this ingredient at this high (P(97.5)) level).