This positively charged material binds the sediment in a quick reaction and provides a more cost-effective solution. It has been on the market since 2013, is protected by 2 patents and is used by approximately 5,000 factories in Ireland and worldwide.

The toxicity of nano iron depends on several factors (e.g. size, shape, structure, surface modifications, concentration, dosage, biodistribution, bioavailability, solubility, immunogenicity and pharmacokinetics). In the 2017 reassessment by EFSA as an additive, red (Fe2O3) and black iron oxide (FeO, Fe2O3) were found to be genotoxic in vitro in mammalian cells, both in nano and micro form.

At the same time, folic acid nanoparticles conjugated with iron oxide can be carrier molecules for anticancer drugs and have been tested as contrast agents in MRI examinations, since the number of folic acid receptors in malignant tumors is high.

Most of the sewage sludge is spread on the land, some goes to landfill or incineration. The substance can enter the food chain through sludge placed on agricultural land, so it is worth considering this food safety risk when introducing sedimentation agents.