Review: SILIFE project

Production of quartz powders with reduced crystalline silica toxicity


The main objective of the EU project SILIFE was to produce commercial quartz powders that show very little or no RCS toxicity, due to a dry surface-coating step.

The main objective of the EU project SILIFE was to produce commercial quartz powders that show very little or no RCS toxicity, due to a dry surface-coating step.

In the SILICOAT project, carried out in the period 2011 to 2014, a coating technology was developed that enables addition of a reagent during preparation of the ceramic compositions, which anchored itself to the quartz particle surface, inhibiting or reducing RCS toxicity. Applied to traditional ceramic processes, this technology proved to be technically and economically feasible for wet processes.

The treated particles exhibited much less toxicity than the untreated particles. However, RCS-containing raw materials are also used in industrial processes in which there are no wet stages. In such processes, the solution provided by the SILICOAT project is, therefore, not directly applicable. To address this constraint, the SILIFE project was initiated in 2015.

The SILIFE project was successfully completed at the end of September 2019.

Go to the website of SILIFE

Methodology used

SILIFE has developed a dry process that is just as effective as the wet process developed in the SILICOAT project. The coating agents used (silanes) anchor themselves to the quartz particles, leading to marked reduction up to nearly complete inhibition of RCS toxicity. Suitable quartzes with lower toxicity can thus be obtained for use in various industrial processes. First, a laboratory mixer was used to verify the feasibility and efficiency of the dry coating method and coating stability.

Once the laboratory-scale method had been established, this was reproduced in a specially prepared industrial mixer for this operation and the scale-up was verified to be feasible. In this facility, a sufficient amount of each quartz provided by the user companies was prepared, using the appropriate and adapted coating agents in each case. Finally, the treated quartz samples were sent to the corresponding companies to verify their feasibility and to Fraunhofer ITEM for toxicity testing. 

Scheme of the technical tasks in the project.

Scheme of the technical tasks in the project.

Industrial trials


Each industrial end user partner conducted industrial trials to identify possible problems.

Although in certain cases some subsequent adjustments of the applied coating agents or of the required coating application conditions were required, the results were generally satisfactory, from the point of view of both execution of the production process and end product quality.


Project dissemination


The advances and results reached by the work team have been disseminated and discussed at congresses, technical conferences, sectorial fairs, follow-up meetings, scientific papers and through the project website:



The technology developed in this project may be deemed available for use on an industrial level. The use of coated quartz in processes that differ from those studied in this project may need only some adaptation by means of a technical feasibility study allowing selection of the most appropriate coating agent in each case.

The possibility of using raw materials with low or zero RCS toxicity can thus be extended to most of the industrial sectors affected by this issue.

The project consortium



itc: Instituto de Tecnología Cerámica Universitat Jaume I (Spain)

Research centers: 

Fraunhofer ITEM (Germany)

Centro Ceramico (Italy)

Technology platform: 

PESI: Plataforma Technológica Española de Seguridad Industrial (Spain)

Material supplier:



Elastomers, Esmalglass, Fumbarri, ITACA and Mapei

Your contact persons at Fraunhofer ITEM

Otto Creutzenberg

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Dr. Otto Creutzenberg

Head of Department of Inhalation Toxicology

Phone +49 511 5350-461

Christina Ziemann

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Dr. Christina Ziemann

Manager of the Working Group on Genetic Toxicology and Tumor Research

Phone +49 511 5350-203