Nanoparticles tested for toxicity

Nanomaterials, substances that have at least one dimension on the scale of atoms and molecules (nanometres), are increasingly a part of modern life. With many more materials in the research and development pipeline, it is important to understand their potential toxic effects.

The EU-funded NANOPOLYTOX (Toxicological impact of nanomaterials derived from processing, weathering and recycling of polymer nanocomposites used in various industrial applications) project evaluated the toxicological impact of various nanomaterials during their life cycle to contribute to the evaluation of the global environmental impact of nano-enabled product via modifications in the classical life-cycle analysis (LCA) methodology. Researchers studied the synthesis, processing, ageing, recycling and disposal of polymers containing nanoparticles.

NANOPOLYTOX produced 18 nanomaterials that have been included in three different polymeric matrices, leading to 18 polymeric nanocomposites to be studied. Each of these materials, including polymers without nanomaterials, was tested as produced and after being subjected to natural or accelerated environmental ageing (weathering conditions, including raining cycles).

Scientists conducted toxicity tests of raw and aged nanomaterials and nanocomposites using human cell lines, fish embryos (in vitro tests) and mice, rats and fish (in vivo tests). These studies included bioaccumulation tests, contributing to the evaluation of potential environmental impacts of these nanocomposite materials.

In general, nanomaterials properties were changing under ageing conditions (oxidation, hydration etc.), and usually lost their surface functionalities, therefore influencing their toxicological effects. Researchers did find that certain nanomaterials bioaccumulated over time in the liver and spleen. Excretion or bioaccumulation of these substances depended on the physical-chemical properties of the nanoparticles.

Through vigorous testing, NANOPOLYTOX addressed a very important safety issue in the growing use of nanomaterials. Standardised testing and material safety datasheets, which exist for all other industrially produced chemicals and materials, should lead to safe manufacture and management of nanomaterials.