Silicic acid, calcium salt

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species: invertebrate

Data waiving:

other justification

Justification for data waiving:

the study does not need to be conducted because the substance has a low potential to cross biological membranes

other:

Justification for type of information:

Silicic acid, calcium salt is an inorganic solid which is insoluble in n-octanol. Due to its inherent physicochemical properties bioaccumulation is not expected.

Log Kow result are not available due to the inorganic nature of the substance.

As the substance is poorly soluble, low concentrations are expected in the aquatic compartment. Low quantities which might be taken up are considered to be not bioavailable. Absorbed Si levels are known to be rapidly excreted in urine and faeces. Thus,calcium silicate contains no bioaccumulation potential.

After oral ingestion, there is no accumulation of synthetic amorphous silica in body tissues. Upon cessation of exposure rapid elimination occurs. Intestinal resorption appears to be insignificant in animals and humans, the small apparent increases in the urine output of human volunteers were remarkably low as compared with the high dose of 2500 mg SiO2 applied subcutaneously are subjected to rapid dissolution and removal.
The inorganic nature of calcium silicate precludes the possibility of metabolic by-products.

There are no concerns regarding toxic effects in any of the (eco-)toxicological studies, short or long term, carried out on the test substance and any analogues. This would indicate that the substance is unlikely to bioaccumulate within biological tissues.

These include
EC10 or NOEC ≥ 0.01 mg/L for marine / freshwater organisms (long-term toxicity)
The substance is not classified as carcinogenic (category 1 or 2), mutagenic (category 1 or 2), or toxic for reproduction (category 1, 2 or 3) according to Directive 67/548/EEC or carcinogenic
(category 1A or 1B), germ cell mutagenic (category 1A or 1B), or toxic for reproduction (category 1A, 1B or 2) according to Regulation EC No 1272/2008
There is no other evidence of chronic toxicity, as identified by the classifications T, R48 or Xn, R48 according to Directive 67/548/EEC or specific target organ toxicity after repeated exposure (STOT RE category 1 or 2) according to Regulation EC No 1272/2008

Reason / purpose for cross-reference:

data waiving: supporting information

Reason / purpose for cross-reference:

data waiving: supporting information

Reason / purpose for cross-reference:

data waiving: supporting information

Reason / purpose for cross-reference:

data waiving: supporting information

Reason / purpose for cross-reference:

data waiving: supporting information

Reason / purpose for cross-reference:

data waiving: supporting information

Reason / purpose for cross-reference:

data waiving: supporting information

Description of key information

Silicic acid, calcium salt is an inorganic solid which is insoluble in n-octanol. Due to its inherent physicochemical properties bioaccumulation is not expected.

Log Kow result are not available due to the inorganic nature of the substance.

As the substance is poorly soluble, low concentrations are expected in the aquatic compartment. Low quantities which might be taken up are considered to be not bioavailable. Absorbed Si levels are known to be rapidly excreted in urine and faeces. Thus,calcium silicate contains no bioaccumulation potential.

After oral ingestion, there is no accumulation of synthetic amorphous silica in body tissues. Upon cessation of exposure rapid elimination occurs. Intestinal resorption appears to be insignificant in animals and humans, the small apparent increases in the urine output of human volunteers were remarkably low as compared with the high dose of 2500 mg SiO2 applied subcutaneously are subjected to rapid dissolution and removal.

The inorganic nature of calcium silicate precludes the possibility of metabolic by-products.

There are no concerns regarding toxic effects in any of the (eco-)toxicological studies, short or long term, carried out on the test substance and any analogues. This would indicate that the substance is unlikely to bioaccumulate within biological tissues.

These include

EC10 or NOEC ≥ 0.01 mg/L for marine / freshwater organisms (long-term toxicity)

The substance is not classified as carcinogenic (category 1 or 2), mutagenic (category 1 or 2), or toxic for reproduction (category 1, 2 or 3) according to Directive 67/548/EEC or carcinogenic

(category 1A or 1B), germ cell mutagenic (category 1A or 1B), or toxic for reproduction (category 1A, 1B or 2) according to Regulation EC No 1272/2008

There is no other evidence of chronic toxicity, as identified by the classifications T, R48 or Xn, R48 according to Directive 67/548/EEC or specific target organ toxicity after repeated exposure (STOT RE category 1 or 2) according to Regulation EC No 1272/2008