Knowledge gaps prevent full risk assessment of supplement nano pigments, study says

By Will Chu

- Last updated on GMT

The European Chemicals Agency (ECHA) has identified a number of knowledge gaps in the hazard and risk assessment of nano-sized pigments used for colouring a range of products including supplements.

Presenting its findings in a newly published report​, the Agency determined that clear evidence-based conclusions on the safety of using nanomaterials could not be drawn based on the presented data.

“The risk assessment is impeded by lack of information on almost all necessary inputs, including lack of information on chemical composition of the paints, characterization of nanomaterials contained in the paint, release factors, daily intake, etc,”​ the report stated.

“The potential for exposure is considered medium as the nanomaterial is suspended in a liquid matrix.

“Neither the release of nanomaterials nor the inhalation exposure during the drying period was demonstrated,”​ it added.

The study, which identified 81 nano-sized pigments currently used in the EU market, found the most commonly occurring uses of pigments in products were in food supplements, food (candies, sweets, chewing gums), cosmetics (sunscreens) and toners.

One ‘high quality’ study

Accompanying studies classed as relevant for risk assessment only included one considered ‘high quality.’ This study​ focused on the risk assessment of titanium dioxide (TiO2) nanoparticles via oral exposure, including toxicokinetic considerations.

Here, TiO2 intake was based on ingestion via food, supplements and toothpaste, and on the average measured total Ti or TiO2 particle levels in such products, according to the Dutch National Food Consumption Survey (DNFCS).

The study found that with Approach one (based on intake, i.e. external doses), a human health risk is not expected for effects in liver and spleen, but a human health risk cannot be excluded for effects on the ovaries.

Approach two, based on organ concentrations by including the toxicokinetics of TiO2, found a potential risk for liver, ovaries and testes.

“The currently estimated risk can be influenced by factors such as absorption, form of TiO2, particle fraction, particle size and physico-chemical properties in relation to toxicity, among others​,” the researchers stated.

“Analysis of actual particle concentrations in human organs, as well as organ concentrations and effects in liver and the reproductive system after chronic exposure to well-characterized TiO2 (NPs) in animals are recommended to refine this assessment.”

Several recommendations made

The report goes on to make several recommendations for further work including an increased emphasis on exposure assessment and control.

Further recommendations include generating well-designed and realistic exposure scenarios on particular nanomaterials for easy access and for benchmarking different safety measures.

The study also stressed the need for enterprises to share sensitive data regarding their production and processes involving nanomaterials, which are necessary for building real-world Exposure Scenarios (ES).

Further support of harmonised approaches in measuring and gathering knowledge on exposure (e.g. through the NECID database - Nano Exposure & Contextual Information Database, MARINA/GUIDEnano library on exposure scenarios, etc.) was also considered of high importance.

Lastly, a map of hypothetical exposure scenarios based on the lifecycle assessment study of the route and extent of human exposure via different pathways for commercially available products containing nanopigments should be elaborated on.

The research team believed this would allow prejudgment on exposure potential and so enable the first attempts on health risk prioritisation.

Related topics Research Supplements

Related news

Show more

Follow us


View more