Dicerium tricarbonate

Endpoint summary

Additional information

Short-term toxicity to fish:

One study of reliability 1 according to Klimisch was available and was selected as a key study .

The acute toxicity of the test item, dicerium tricarbonate, to rainbow trout (Oncorhynchus mykiss) was determined in a 96-hour semi-static test with a daily test medium renewal according to the EU Commission Directive 92/69/EEC, Part C.1 (1992), and the OECD Guideline for Testing of Chemicals No. 203 (1992).Fish were exposed to control and test chemical at a loading rate of 100 mg/L for 96h. Mortality and visible abnormalities were observed daily. No mortality or other visible abnormalities were observed during the test.The 96-hour NOELR and the 96-hour LL50 of dicerium tricarbonate to rainbow trout were thus determined to be > 100 mg/. In conclusion, the test item dicerium tricarbonate had no acute toxic effects on rainbow trout up to the solubility limit in the test water, at the loading rate of 100 mg/L.

 

Short-term toxicity to aquatic invertebrates:

One study of reliability 1 according to Klimisch was available and was selected as a key study .

The 48hr-acute toxicity of cerium carbonate to Daphnia magna was studied under static conditions according to the EU Commission Directive 92/69/EEC, Part C.2 (1992) and the OECD Guideline for Testing of Chemicals, N°202 (2004). Daphnids were exposed to control and test chemical at nominal concentration of 100 mg of dry substance /L (loading rate) for 48 hr. Mortality/immobilization were observed daily. In the control and at the loading rate of 100 mg/L, no immobilized test organisms were observed during the test period of 48 h. Thus, the 48 hour LL50 was > 100 mg/L and the 48h NOEC were >= 100 mg/L.

Long-term toxicity to aquatic invertebrates:

One study of reliability 1 according to Klimisch was available and was selected as a key study.

The effect of the test item, dicerium tricarbonate, on the survival and reproduction of Daphnia magna was investigated in a semi-static test over 21 days following the OECD Guidelines for Testing of Chemicals, No. 211 (1998) and the EU Commission Directive 92/69/EEC, C.20 (2001). Daphnids were exposed to control, and test chemical at nominal concentration of 130 mg of dry substance /L (loading rate) and the dilutions 1:3.2, 1:10, 1:32 and 1:100 of the saturated solution. The mortality and reproduction of the daphnids were compared with the corresponding parameters in the control and symptoms of toxicity were recorded. The test item, dicerium tricarbonate, had no toxic effect on survival and reproduction of Daphnia magna after the exposure period of 21 days up to the loading rate of 130 mg/L. Thus, the NOELR of the test item was determined to be at least the loading rate of 130 mg/L (100 mg/L, when corrected for the water content of the test item). The LOELR was above the loading rate of 130 mg/L.

 Toxicity to aquatic algae:

One study of reliability 1 according to Klimisch was available and was selected as a key study.

The influence of dicerium tricarbonate on the growth of the green algal species Scenedesmus subspicatus was investigated in a 72 -hour static test according to guidelines EU C.3 (1992) and OCDE 201 (2006). The GLP were stated. Algal suspensions were exposed to the test item with a loading rate of 100 mg/L (corrected for water content) and to dilutions 1:2, 1:4, 1:8, 1:16, 1:32. Additionally, a control was tested in parallel.
The algal cell densities were counted daily, and inhibition of algal growth was assessed.
The inhibition of algal growth observed only at the two highest concentrations, i.e. 50 and 100 mg/L, was presumably caused by a secondary effect, the complexation of the essential algal nutrient phosphate by the test item. A statistically significant decrease of the phosphate concentration was determined at the loading rates of 50 and 100 mg/L. Thus the growth inhibition determined at these loading rates has probably been caused by depletion of phosphate in the test medium.

 

Toxicity to microorganisms:

One study of reliability 1 according to Klimisch was available and was selected as a key study.

The inhibitory effect of the test item dicerium tricarbonate on the respiration rate of aerobic wastewater microorganisms of activated sludge was investigated in a 3-hour respiration inhibition test according to the EU Commission Directive 88/302/EEC, Part C.11, and the OECD Guideline for Testing of Chemicals, No. 209.

In accordance with the EU Commission Directive 92/69/EEC (C.1, C.2, and C.3) and the OECD Series on Testing and Assessment No. 23 (Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, 2000), a limit test was performed with one concentration of dicerium tricarbonate of nominal 1000 mg/L, to demonstrate that the test item has no toxic effect on activated sludge microorganisms up to and including this concentration.

In addition, two controls and three different concentrations of the reference item 3,5 dichlorophenol (5, 16, and 50 mg/L) were tested in parallel. The results of these reference treatments (EC50 = 12 mg/L within the guideline-recommended range of 5 - 30 mg/L) confirmed suitability of the activated sludge and the method used.

The test item, dicerium tricarbonate, had no significant inhibitory effect on the respiration rate of activated sludge after the incubation period of three hours at the limit test concentration of 1000 mg/L. Thus, the 3-hour NOEC of dicerium tricarbonate to activated sludge microorganisms was at the limit of water solubility of dicerium tricarbonate under the test conditions, or at 1000 mg/L. The 3-hour EC20, EC50 and EC80 were clearly higher than the limit of water solubility of dicerium tricarbonate under the test conditions, or higher than 1000 mg/L.

 

 

In summary, dicerium tricarbonate did not induce anyadverse effects up to its solubility limit into water.