About ConsExpo nano, a short introduction to the tool for consumer exposure to nanomaterials in consumer spray products.
Consumers are potentially exposed to nanomaterials during use
of nano-enabled consumer products. Of particular concern is the
application of nanomaterials in spray products. To investigate the
exposure of the consumer to nanomaterials in these products, RIVM
developed a new software model: ConsExpo nano. This model was
adapted from the ConsExpo model for the estimation of exposure to
regular substances in spray products. It has been developed in the
context of the NanoNextNl project: “Predictive modeling of human
During use of a consumer spray product, the nanomaterial that is
released from the spray may become airborne as part of the spray
aerosol or as individual particles. Exposure to a nanomaterial in
an aerosol may take place via different routes, but inhalation of
the aerosol is generally considered the route of most concern.
According to Braakhuis et al. (2014), the most relevant effect
after inhalation exposure to nanomaterials is the induction of
inflammation in the alveoli. One of the most critical determinants
of this effect is both the magnitude and duration of the alveolar
load of a nanomaterial. To estimate the alveolar load arising from
the use of nano-enabled spray products, ConsExpo nano combines
models that estimate the external aerosol concentration in indoor
air, with models that estimate the deposition in and clearance of
inhaled aerosol from the alveolar region.
Another issue addressed in ConsExpo nano is the observation that
the traditional choice of ‘mass of the substance inhaled’ as a
measure of exposure is inappropriate to quantify dose-effect
relations for nanomaterials. Alternative dose metrics such as total
number or total surface area of the nanoparticles inhaled have been
suggested, but consensus on an appropriate dose metric is currently
lacking. To bridge this current knowledge gap, ConsExpo nano
expresses exposure estimates in a variety of dose metrics, allowing
the exposure assessor to evaluate various alternatives.
In April 2016, the tool is updated according to comments and
suggestions from users. In the new version of the tool, version
1.1, two major changes have been implemented. First, apart from a
spray scenario, the user is able to choose a custom scenario in
which a known air concentration of aerosols (containing
nanomaterials) can be entered directly into the tool. This option
enables the user to calculate an alveolar load in lungs from any
inhalation exposure (outside spray exposure), which makes the tool
applicable for scenarios other than spray scenarios, including
those occuring at the workplace.
Furthermore, there is a possibility to enter exposure parameters of
an animal hazard study with known adverse effects after inhalation
exposure to a nanomaterial. In this way, it is possible to convert
the external dose of nanomaterials to which the animals are
exposed, into an internal exposure dose i.e. the alveolar load. In
this way, a comparison (indication of risk) can be based on
comparison of the alveolar load.
Currently, there is still a lack of knowledge and data on the
exposure assessment and risk assessment for nanomaterials. ConsExpo
nano is a “work-in-progress” online tool that is designed to
reflect the current state of knowledge on exposure to nanomaterials
via inhalation. See also the Proclaimer for the use of the ConsExpo
Nano online tool. The tool will be further developed to accommodate
developments in the state of the science.
We therefore highly appreciate your comments and additional
information to improve the model. Please send your comments to