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EC number: 915-037-6
CAS number: -
Silicon and calcium are practically taken always present in soil
minerals and dissolved in soil pore water. Anthropogenic and potentially
bioavailable silicon in soil is present in oxidized form as silica Si(OH)4and
calcium as ionized Ca (II).
Terrestrial toxicity of calcium and silica are expected to be low,
since soil dwelling species are well adapted to the presence of these
elements in soil and soil pore water. Some soil types may be very rich
or almost entirely built from these minerals. Calcium is essential for
all and silica is essential for some of soil living species.
No standard studies or information has been located showing
toxicity of silica to soil dwelling species. Based on the results of
short term pelagic tests (algae, fish) acute lethal effects might be
avoided if the soil pore water concentration remains below the colloid
forming/saturation concentration (>
160 mg/L (at 20-25°C)).
It has been observed that normally the concentration of silica in soil
pore water remains relatively constant and clearly below the
saturation/polymerization concentrations. Long term effects data is not
Adaptation to high natural silica or calcium concentration may be
species sensitive and the most tolerable species favor the extreme
conditions. For instance, species may live in soil type called
“diatomaceous earth” also known as “diatomite’ or “kieselgur’, which is
a naturally occurring, siliceous (amorphous SiO2> 90%)
sedimentary soil type and mineral. It has a particle size ranging from
less than 1 micron to more than 1 millimeter, but typically 10 to 200
It has been observed that normally the concentration of silica in
soil pore water remains relatively constant and clearly below the
saturation/polymerization concentrations. Adsorption of soluble silica
to soil minerals is a more favorable fate process than remaining in the
aqueous phase in high concentrations. On the other hand the dynamic
equilibrium helps in keeping the concentrations relatively stable since
desorption may rapidly increase the soil pore water concentration to
some extent. Ultimately it is the mineral composition of soil in a
geological area that in the long term determines the concentration
levels of dissolved silica found regionally.
adaptation rules offer the possibility to apply weight of evidence
approach instead of testing. In estimation of hazard of CaSi, the read
across method may be utilized in the first hand by applying the already
existing hazard data. Based on already existing information, it is
currently not seen necessary to have any targeted ecotoxicological
testing of CaSi in soil. All the main and minor constituent elements Ca,
Si and Fe, Al, Ti are all very common elements present in soil minerals
and soil (fine) particulate matter and generally these elements are not
regarded specifically hazardous elements in soil environment and
therefore hazard profile of these element is rather low. In
addition, the manufacture and use categories indicate no direct and
remarkable exposure to soil compartment (SU3, 14 PC 7,11, PROC 3, 4, 5,
8a, 8b, 9, 20, 21, 22).
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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