RIVM has developed the software “ConsExpo” which uses descriptive parameters to estimate consumer exposure to various products. The currently available web-based version ConsExpo 4.1 (ConsExpo, Update 2010) includes a mathematical model for estimation of inhalation exposures. Upon inclusion of basic data (Bremmer et al., 2006a and Bremmer screening assay et al., 2006b) and specific product information, the software is able to generate individual exposure scenarios taking into account temporal changes of particle concentration in the ambient air. Table 3 lists the parameters required for exposure calculations according to ConsExpo. The software also allows the calculation of the combined dermal and respiratory exposure during

the application of cosmetic sprays, and the estimation of the total systemic exposure to a given BTK inhibitor substance

as required for a risk assessment. For the calculation of systemic exposure from sprays, mathematical models from publicly available software packages such as SprayExpo (Koch et al., 2004), and the model BG-Spray described by Eickmann (2007a) can be used. The advantages and drawbacks of the different models have been discussed elsewhere (Eickmann et al., 2007b). The basis of the safety evaluation of cosmetic products is the comprehensive information on ingredients used, especially their specifications and toxicological profiles. A number of biologically active ingredients have been restricted by regulations and the use of certain substances in sprays, such as dehydroacetic acid, have been banned in the EU (European Commission, 1976, Annex VI Entry No. 13 EC-Cosmetics-Directive 76/768/EC). When evaluating the safety of ingredients in sprays from the inhalation related point of view, the assessor needs to consider where these compounds may come into contact with the respiratory tract and Montelukast Sodium where possible adverse effects may occur: e.g., local irritation of the

respiratory tract, systemic effects following inhalation exposure, respiratory sensitization and local toxicity in the deep lung. Table 4 lists ingredients typically found in cosmetic spray products. For propellant gases and highly volatile solvents, a quantitative alveolar availability should be assumed. Results from at least one repeated dose inhalation study should be available to allow the assessment of the systemic toxicity and local effects in the respiratory tract. As a second option, the systemic load may be estimated on the basis of ambient air concentrations and respiratory minute volume. The solid compounds in hair sprays are usually polymers. The majority of these polymers have low biological reactivity or are inert (Carthew et al., 2002). However, inhalation of high doses of inert particles may produce particle overload of the lung resulting in inflammatory changes in a dose-dependent manner (Greim et al., 2001 and Muhle and Mangelsdorf, 2003). Absorption and systemic availability of insoluble particles after deep lung exposure is unlikely.