Size-fractionated characterization and quantification of nanoparticle release rates from a consumer spray product containing engineered nanoparticles

Abstract

This study describes methods developed for reliable quantification of size-and element-specific release of engineered nanoparticles (ENP) from consumer spray products. A modified glove box setup was designed to allow controlled spray experiments in a particle-minimized environment. Time dependence of the particle size distribution in a size range of 10-500 nm and ENP release rates were studied using a scanning mobility particle sizer (SMPS). In parallel, the aerosol was transferred to a size-calibrated electrostatic TEM sampler. The deposited particles were investigated using electron microscopy techniques in combination with image processing software. This approach enables the chemical and morphological characterization as well as quantification of released nanoparticles from a spray product. The differentiation of solid ENP from the released nano-sized droplets was achieved by applying a thermo-desorbing unit. After optimization, the setup was applied to investigate different spray situations using both pump and gas propellant spray dispensers for a commercially available water-based nano-silver spray. The pump spray situation showed no measurable nanoparticle release, 123J Nanopart Res (2010) 12:2481-2494 DOI 10.1007 whereas in the case of the gas spray, a significant release was observed. From the results it can be assumed that the homogeneously distributed ENP from the original dispersion grow in size and change morphology during and after the spray process but still exist as nanometer particles of size \100 nm. Furthermore, it seems that the release of ENP correlates with the generated aerosol droplet size distribution produced by the spray vessel type used. This is the first study presenting results concerning the release of ENP from spray products.

Comparative modeling of exposure to airborne nanoparticles released by consumer spray products

“…Exposure to NPs via the respiratory tract is considered as the most likely situation that could lead to hazardous effects for the consumer (Hagendorfer et al, 2010). This concern is partly owed to the large surface of the lung.…”

“…In most cases spray applications were examined; and silver was the most frequently used nanomaterial in the spray applications. An experimental setup for the measurement of NPs in sprays was described by Hagendorfer et al (2010). Two different atomizers were used and the droplet size determined of an aqueous spray liquid containing silver NPs.…”

Detection, characterization and quantification of inorganic engineered nanomaterials: A review of techniques and methodological approaches for the analysis of complex samples

“…Luo et al [81] explored the application of ESEM to directly characterize the size distribution of a range of The use of electron microscopy for ENMs characterization in different types of samples has been considered in different reviews involving environmental [7,8,83], food [8,20], and biomaterials [71] analysis. In relation with complex samples, electron microscopy has been successfully applied to characterize TiO 2 nanoparticles in sewage sludge and soils amended with sewage sludge [84] or with biosolids [85], or to investigate the presence of ENPs in release studies: Ag NPs from a washing machine effluent [86] and from water-based nano-Ag spray products [87], TiO 2 NPs from textiles [88], or SiO 2 and Al 2 O 3 from chemical mechanical planarization process wastewater [89]. SEM and TEM-based studies highlighted the relevance of the detection and characterisation of ENPs in many products of our daily life: Ag in washing solutions from commercial detergents [90], Ag and ZnO in spray products [91], TiO 2 and ZnO in sunscreens [74], metallic NPs in dietary supplement drinks [92], Ag in pears [93], SiO 2 in tomato soup [81] or coffee creamer [55], TiO 2 and ZnO in starch, yam starch, and wheat flour [94], or TiO 2 in foods and consumer product [95].…”

Conceptual model for assessment of inhalation exposure to manufactured nanoparticles

“…In an experimental setting, N rgaard et al (2009) and Hagendorfer et al (2010) investigated the release of volatile organic solvents and aerosols during application of commercially available nanofilm spray products. Koponen et al (2009) and Bello et al (2009) investigated release of particles following sanding and cutting of CNT composites, respectively.…”

“…Most, if not all, of these applications attempt to form a nanosized layer on a surface. Application of nanofilm products using hand spray bottles or pressurized cans can generate airborne particles below 100 nm (N rgaard et al, 2009;Hagendorfer et al, 2010), with the particle number concentration and size distribution strongly depending on the spray technique (i.e., pressurized or pump), the type of product, and the configuration of the tip. The number of aerosol particles released was dominated by the nanosized particles, but they were formed by different processes: (1) evaporation and condensation processes in the air, (2) liberation of free engineered nanoparticles after evaporation of the solvent, (3) particle formation during spraying and secondary particle formation due to atmosphere chemical reactions.…”