Particle size distribution in the evaluation of the inhalation toxicity of cosmetic spray products.

While applying cosmetic sprays (pump sprays and propellant-based sprays) intended for use on the skin or hair, consumers may unintentionally inhale sprayed droplets/particles. Thus, it is essential to analyze the size distribution of sprayed droplets/particles because those less than 10 µm are considered to be respirable and may present a high systemic and local exposure risk. In this study, we investigated the droplet/particle size distribution of 78 cosmetic sprays by laser diffraction. Our results showed that the level of respirable droplets/particles released by pump sprays averaged 0.5% of all particles measured (0.00%-2.23%) and that released by propellant-based sprays averaged 15.25% (0.15%-32.27%). Dry shampoos (powder) released the highest percentage of respirable droplets/particles (16.66%-32.27%). A default value of 25% of respirable droplets/particles can also be suggested for dry shampoos. Droplet/particle size distribution was influenced by the spray dispensing system (pump or propellant-based), the product type (hairspray, sunscreen, etc.) and the galenic form (powder, oil, emulsion, etc.). However, it should be noted that more confidence is placed in the pump spray data due to the larger sample size. This study provides data on droplet/particle size, which may be used in a modelling approach to predict inhalation exposure. Therefore, it must be known and used, together with assessments of intrinsic and local toxicities to determine the margin of safety of the product by inhalation route, and to assess the risk of cosmetic sprays.

In vitro measurement of skin sensitization hazard of mixtures and finished products: Results obtained with the SENS-IS assays.

Product safety evaluation in the EU is based on data mainly obtained on individual ingredients. However, mixture effects have been demonstrated in numerous skin sensitization studies due to the presence of irritating chemicals or to modification of dermal absorption. To evaluate the ability of the SENS-IS assay to detect such mixture effects, we performed three sets of experiments: First, the importance of the vehicle on absorption of individual ingredients was evaluated by testing the effect of commonly used cosmetic preparations on the sensitizing potential of 3 chemical allergens and 2 fragrance blends. The sensitizing potential of the 3 allergens was significantly reduced when tested in microemulsion while the "cleansing water" preparation significantly increased it. Water in oil, oil in water or oil preparations had significant but more moderate (enhancing or reducing) effects on the skin sensitization potency of the tested chemicals. We then analyzed the influence of irritants (SDS and Lactic acid) on the sensitizing potency of various allergens. The SENS-IS assay detected an enhancement of the potency of some allergens when mixed with non-irritating concentrations of irritant chemicals. We also tested the influence of mixing different sensitizers to analyze the effect of mixtures on the sensitization threshold. Some mixtures of chemicals, at doses that did not induce a positive signal in the SENS-IS assay alone, became positive, indicating a mixture effect. Finally we tested commercially available finished cosmetic products to find out that they were not all negative. These results indicate that the SENS-IS assay is a valuable source of information when analyzing mixture component effects and finished products.