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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Testing has not been carried out on Synthetic Wollastonite however testing  on the read-across material Kieselguhr soda ash flux calcined was carried out at 3 trophic levels (algae, daphnia and fish) in reliable OECD guideline studies. In each study the L(E)C50s were greater than the solubility of the substance (ie 100% v/v saturated solution).

Long-term toxicity studies were not conducted for fish and daphnia due to the lack of acute toxicity.

Additional information

Read-Across Justification

Synthetic wollastonite is a UVCB substance, the main constituents of which are amorphous in nature. It also contains crystalline silica. The percentage of crystalline silica may range up to 1.5% (<=0.21% respirable). Acute toxicity to fish, invertebrtates and algae, and toxicity to micro-organisms information has been read-across from the analogue substance Kieselguhr, soda ash flux-calcined. The analogue has been chosen for its similarity in structure and properties to Synthetic wollastonite. The main difference in structure between Synthetic wollastonite and Kieselguhr, soda ash flux-calcined is the presence of a calcium ion in Synthetic wollastonite. It is clear from a number of studies carried out on amorphous and crystalline silica and the analogue substance Silicic acid, calcium salt that results were consistent between the two substances and that there was no effect from the presence of the calcium ion. Moreover, it is well documented that these substances have a low potential for hazard to health and the environment. 

Synthetic wollastonite is poorly soluble in water and consists of amorphous and crystalline silica which naturally occur in water bodies. The registered substance is not expected to be harmful to aquatic organisms.

Based on the results of testing on the analogue substance Kieselghur soda ash flux calcined, the test substance Synthetic Wollastonite can be considered to be not classified for aquatic toxicity.