The modelling exposure to nano materials in spray products documentation provides background information on the models that are implemented in the ConsExpo nano tool. The user manual  provides a description of the input needed by the tool and the output options that the tool provides. 

The DustEx model is used to assess exposure to  semi-volatile substances (SVOCs) in products that are introduced into the indoor environment. The typical products considered are solid material products (e.g. flooring, wall covering, electronic devices) from which substances are released into indoor air and subsequently transported into different indoor compartments airborne particles, indoor surfaces and dust. Exposure takes place from the inhalation of the substance in the gas phase, the inhalation of substance bound to airborne particles, the dermal absorption of the substance from air (gas phase) and the oral ingestion of the substance with dust. For SVOCs released indoors it may not be clear beforehand which exposure pathway(s) will be relevant. The DustEx model considers all pathways and will therefore enable a more complete assessment of exposure, reducing the probability of overlooking the most crucial pathways in the exposure assessment. In developing the DustEx model, a number of simplifying assumptions were made. These put limits on the applicability of the model in exposure assessments. Model framework The DustEx model is a kinetic source to dose model that contains dynamic mass balance equations describing emission and fate of the substance indoors. The integration of the system of equations using suitable boundary and initial conditions (i.e. reflecting the specific exposure scenario), gives the concentrations of a substance in all different compartments (air, product, dust, airborne particles, indoor surfaces) as a function of time. Estimates of the concentration in the different indoor compartments are combined with equations estimating exposure from contact with these media. A graphical representation of the components and physical processes considered in the kinetic source to dose model. The substance is emitted from the product into bulk indoor air by evaporation. From air, the substance will partition to airborne particulate matter, dust and will sorb to indoor surfaces. Removal of the substance from the indoor environment takes place via ventilation and vacuum cleaning. Exposure of a person present in the indoor environment stems from the inhalation of the substance in gas phase and bound to particles, the dermal absorption of the substance from air (gas phase), and the ingestion of the substance with dust. More detailed information can be found in the subsections “Equations describing emission and transfer of a substance indoors”, “Models for exposure evaluation” and “Working with the DustEx web application”. If you have questions or suggestions for the improvement of DustEx, please contact us at dustex@rivm.nl.

ConsExpo nano is a tool to investigate potential consumer exposure to nanomaterials in consumer spray products. To estimate the exposure of the consumer to nanomaterials from these products, the ConsExpo nano tool has been developed, which was adapted from the ConsExpo model for the estimation of exposure to regular substances in spray products. The tool is freely accessible at www.consexponano.nl

PACEM Some chemical substances, for example some fragrances and preservatives, are used in many consumer products. Examples are personal care products (e.g. shampoo, body lotion, soap), household cleaning products and do-it-yourself products. So, in one single day a person can be exposed to these substances via multiple products. To estimate the total daily exposure of a person, the exposures from all products used on that day need to be summed. For this purpose the Probabilistic Aggregate Consumer Exposure Model (PACEM) has been developed by RIVM, in cooperation with ETH Zürich and Radboud University of Nijmegen. This work has been funded by the Ministry of Public Health, Welfare and Sports and by the CEFIC Long Range Initiative program. The model is based on realistic product usage information obtained from surveys. Currently, information on the usage (frequency and amount) of personal care products and household cleaning products in various European countries is included. PACEM has been applied and tested for a number of substances. These were: diethyl phthalate (Delmaar et al. 2014), parabens (Gosens et al. 2014), decamethylcyclopentasiloxane (D5, Dudzina et al. 2015), geraniol (Nijkamp et al. 2015; Jongeneel et al. 2018), isothiazolinones (Ezendam et al (2018); Garcia-Hidalgo et al. 2018) and bisphenols (Karrer et al. 2019). In 2021, in a project funded by the Long Range Science Strategy (LRSS) program of Cosmetics Europe, the PACEM model as described in Ezendam et al (2018) has been made available in a web tool: PACEMweb.   For questions or comments you can contact us at pacemweb@rivm.nl.  

With respect to regulation of chemical substances in consumer products, different international legislative frameworks are relevant. The use and production of all substances that are processed in consumer products is regulated by REACH

Exposure factors are aspects (of e.g. our behaviour or the environment) that influence how closely we come in contact with stressors such as, for example, chemical substances. Important exposure factors are consumption of food and beverages, housing conditions, time spent in close contact with a stressor, but also inhalation rates and consumer products usage.

Aggregate exposure is the exposure to one single chemical via all exposure routes (dermal, oral and inhalatory) and from different sources (for example several different consumer products and/ or in combination with food).

Knowledge on the exposure part of the risk assessment is equally important as knowledge on the toxicological endpoints, but this knowledge is scarce. In exposure assessment, attention for a sensitive subpopulation such as for example children is important. 

Nanotechnologies and nanomaterials are applied in consumer products. Examples of consumer products that are claimed to contain nanoparticles or produced using nanotechnology, are the use of titanium dioxide in sunscreens, cerium oxide nanoparticles in diesel for combustion improvement and antibacterial properties of silver nanoparticles in wound dressings, textiles or large appliances.