According to these researchers from the Swiss Federal Institute of Technology, although there has been some level of requirement for cosmetics in recent years, there has been a move away from labelling nanomaterials across all consumer spray products.
Thus, in order to produce comparable data, they suggest that 'adequate techniques' should be identified to determine the size of nanoparticles inside spray droplets.
According to the lead author of the study published in the International Journal of Nanomedicine, Natalie von Goetz from ETH Zurich; “Nanoparticle-containing sprays are less studied, although they are perceived as critical for consumers because inhalation exposure can occur to potentially toxic nanoparticles."
To address this issue, the scientists sought to compare exposure data from existing studies, but reported the techniques to have 'differed greatly'.
Suggesting a 'standardised experimental setup'
Alongside fellow scientists, Dr von Goetz developed a physiologically-based pharmacokinetic (PBPK) model for ionic silver and silver nanoparticles, which the team says could be used for exposure analysis and risk assessment of a range of products, including sprays.
However; the researchers are still calling for 'improved reporting' in that more information could be included in the experimental setting and on the types of spray cans used. "A standardised experimental setup would help greatly."
The team has moved on to establish the rates at which gold nanoparticles can be taken into the human body.
"Such work is needed to judge whether a nanoparticle that has been assessed with having in vitro effects may actually reach a target inside the body, or whether the effect is purely academic," says Dr von Goetz.