Silicic acid, ethyl ester

Endpoint summary

Description of key information

Short-term toxicity to fish:

Short term toxicity of test material was evaluated on Brachydanio rerio for 96 hr under semistatic condition according to Directive 92/69/EEC, C.1 . The test substance was added to the synthetic fresh water to provide a concentration of 1 g/l, and was stirred for 18 hours. Then the solution was filtered and the carbon content was determined. A single test concentration of 119 mg/l was measured for this study. Fish were held in dechlorinated circulating potable water in 200 -liter stoneware tanks or in 300-liter glass aquariums, at 20 deg C. Daily feed amounts of TetraMin®, approximately 1% of body weight, were supplied. The specimens were pre-conditioned (treatment: 3x per week with malachite green) and subjected to a 14-day quarantine. They were used in testing only after this treatment. Only specimens displaying normal behavior at the beginning of the test and free of obvious disease were used in the study. Fish were not fed during the test. The testing density was 10 specimens per test tank; 0.4 g each. Ten fish per 20 l test aquarium were exposed for 96 hrs to a test substance concentration of 0 or 119 mg/l. LC0 observed after 96 h was 119 mg/l .No mortalities were observed.

Short-term toxicity to aquatic invertebrates:

Aim of this study was to assess the short term toxicity of test material to aquatic invertebrates daphnia magna. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) in a static system for the total exposure period of 48 hrs.

 The stock solution 10 g / l was prepared by dissolving colourless iquid in acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with reconstituted test water.0.5 , 1.0 , 2.0 , 4.0 , 8.0 , 16.0 mg/lconcentrations were used in the study. Effects on immobilisation were observed for 48 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0.

 The median effective concentration (EC50) for the test substance , in Daphnia magna was determined to be 6.1 mg/L on the basis of mobility inhibition effects in a 48 hour study. Based on the EC50 value, substance is likely to be hazardous to aquatic invertebrate can be classified as aquatic chronic 2 category as per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria:

Aim of this study was to evaluate the nature of chemical test chemical when comes in contact with the test organism Desmodesmus subspicatus (previous name: Scenedesmus subspicatus). Test was conducted according to the OECD guideline 201.The stock solution 10 g/l  was prepared by dissolving colourless liquid in acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture.0.5 , 1.3 , 3.2 , 8.0 , 20 mg/lconcentration were used.

With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determine after an exposure period of 72 hrs.

The median effective concentration (EC50) for the test substance , in algae was determined to be >20 mg/L on the basis of growth rate inhibition effects in a 72 hour study.

Toxicity to microorganisms:

The Oxygen consumption test (Huls method) was performed for test material on Pseudomonas putida (Bacteria). Four 100-ml von Loh bottles with ground glass stoppers were coated with the culture solution, the bacterial suspension, and the test substance in staged concentrations (0, 100, 500, 1000 and 2000 mg/l), were sealed without air, and were incubated for 5 to 6 hours at approximately 25 degC. Two were treated with HgCl2 solution to kill the bacteria, and serve to determine auto-oxidation grades of the test substance. Nine control bottles without the test substance were used as reference; four of these contained HgCl2 to determine the final oxygen content. At the end of testing HCl was added to stop biochemical processes. The EC10 evaluted after 5 h based on the Oxygen consumption of test organims was observed to be 2000 mg/l

Additional information

Short-term toxicity to fish:

The effect of test material on fish was observed based on the data for target chemical from secondary source as well as data for read across substances

For the target substance ,short term toxicity of test material was evaluated on Brachydanio rerio for 96 hr under semistatic condition according to Directive 92/69/EEC, C.1 . The test substance was added to the synthetic fresh water to provide a concentration of 1 g/l, and was stirred for 18 hours. Then the solution was filtered and the carbon content was determined. A single test concentration of 119 mg/l was measured for this study. Fish were held in dechlorinated circulating potable water in 200 -liter stoneware tanks or in 300-liter glass aquariums, at 20 deg C. Daily feed amounts of TetraMin®, approximately 1% of body weight, were supplied. The specimens were pre-conditioned (treatment: 3x per week with malachite green) and subjected to a 14-day quarantine. They were used in testing only after this treatment. Only specimens displaying normal behavior at the beginning of the test and free of obvious disease were used in the study. Fish were not fed during the test. The testing density was 10 specimens per test tank; 0.4 g each. Ten fish per 20 l test aquarium were exposed for 96 hrs to a test substance concentration of 0 or 119 mg/l. LC0 observed after 96 h was 119 mg/l .No mortalities were observed.

The above data was supported by data for structurally similar read across substanceaccording to secondary source the Short term toxicity to fishBrachydanio reriosuggest the test was performed in semi-static condition for 96-hr exposure period and limit test following Directive 92/69EEC, C.1 (Huls AG, 1993a).During experiment the LC0 value for short term toxicity to fish for test material was determined to be 119 mg/l.

Based on the value, the test material was considered to be non-toxic to fish and can be considered to be not classified as per the CLP regulations.

The above data was further supported by data for functionally similar read across substance according to secondary source the Short term toxicity to fish Brachydanio rerio suggest the test was performed in semi-static condition for 96-hr exposure period and limit test following Directive 92/69/EEC, C.1 (Degussa-Huls AG, 1993c).During experiment the LC0 value for short term toxicity to fish for test material was determined to be 245 mg/l.

Based on the value, the test material was considered to be non-toxic to fish and can be considered to be not classified as per the CLP regulations.

Short-term toxicity to aquatic invertebrates:

Aim of this study was to assess the short term toxicity of test material to aquatic invertebrates daphnia magna. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) in a static system for the total exposure period of 48 hrs.

 The stock solution 10 g / l was prepared by dissolving colourless iquid in acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with reconstituted test water.0.5 , 1.0 , 2.0 , 4.0 , 8.0 , 16.0 mg/lconcentrations were used in the study. Effects on immobilisation were observed for 48 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0.

 The median effective concentration (EC50) for the test substance , in Daphnia magna was determined to be 6.1 mg/L on the basis of mobility inhibition effects in a 48 hour study. Based on the EC50 value, substance is likely to be hazardous to aquatic invertebrate can be classified as aquatic chronic 2 category as per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria:

Aim of this study was to evaluate the nature of chemical test chemical when comes in contact with the test organism Desmodesmus subspicatus (previous name: Scenedesmus subspicatus). Test was conducted according to the OECD guideline 201.The stock solution 10 g/l  was prepared by dissolving colourless liquid in acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture.0.5 , 1.3 , 3.2 , 8.0 , 20 mg/lconcentration were used.

With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determine after an exposure period of 72 hrs.

The median effective concentration (EC50) for the test substance , in algae was determined to be >20 mg/L on the basis of growth rate inhibition effects in a 72 hour study.

Toxicity to microorganisms:

The Oxygen consumption test (Huls method) was performed for test material on Pseudomonas putida (Bacteria). Four 100-ml von Loh bottles with ground glass stoppers were coated with the culture solution, the bacterial suspension, and the test substance in staged concentrations (0, 100, 500, 1000 and 2000 mg/l), were sealed without air, and were incubated for 5 to 6 hours at approximately 25 degC. Two were treated with HgCl2 solution to kill the bacteria, and serve to determine auto-oxidation grades of the test substance. Nine control bottles without the test substance were used as reference; four of these contained HgCl2 to determine the final oxygen content. At the end of testing HCl was added to stop biochemical processes. The EC10 evaluted after 5 h based on the Oxygen consumption of test organims was observed to be 2000 mg/l