Bis(acetato-O)hydroxyaluminium

Endpoint summary

Description of key information

Short-term toxicity to fish:

In this 96-hour static acute toxicity test on Zebrafish (Danio rerio, reference 6.1.1 -1) the test item Aluminium hydroxide diacetate hydrate had no toxic effect on fish at aquatic saturation (measured value: 1.46 mg/L; equivalent to 100 mg/L nominal concentration). Accordingly, the 96-h LC50 value was determined to be >1.46 mg/L (equivalent to 100 mg/L nominal concentration). The 96-h NOEC was determined to be 1.46 mg/L (equivalent to 100 mg/L nominal concentration). Based on the molecular weight the recalculated NOEC for the anhydrous substance is 1.31 mg/L. The LOEC and the LC50 for the anhydrous substance was calculated to be higher than 1.31 mg/L.

Short-term toxicity to invertebrates:

In this 48-hour static acute toxicity limit test with Daphnia magna the effects of Aluminium hydroxide diacetate hydrate on the mobility was determined. The 48-h EC50 value was determined to be >0.96 mg/L (hydrated substance) and >0.86 mg/L (calculated for anhydrous substance). The 48-h NOEC was determined to be 0.96 mg/L (hydrated substance) and 0.86 mg/L (calculated for anhydrous substance).

Toxicity to aquatic algae:

The effect of the test item on the growth of a unicellular green algal species Raphidocelis subcapitata was determined according to OECD 201, Regulation (EC) No. 226/2016 Method C.3 and EPA OPPTS 850.5400 and under GLP (reference 6.1.5-1). The study was conducted under static conditions with an initial cell density of 1x10^4 cells/mL for a period of 72 hours. The EC50 and EC10 based on growth rate were determined to be 1.02 mg/L and 0.72 mg/L (hydrated substance, mean measured), and 0.92 mg/L and 0.66 mg/L (calculated value for anhydrous substance), respectively.

Toxicity to microorganisms:

Under the conditions of the performed Activated Sludge Respiration Inhibition Test (reference 6.1.7-1), the EC10 and EC50 values of test item was determined as higher than 1000 mg/L. Based on the statistical evaluation in this test the NOEC was 1000 mg/L. This pre-test demonstrated the absence of inhibition of oxygen consumption of the test item up to and including the limit concentration of 1000 mg/L, therefore in line with OECD guideline 209 an additional definite test is not required. Based on the molecular weight the recalculated EC10 and EC50 for the anhydrous substance is higher than 900 mg/L and the NOEC for the anhydrous substance is 900 mg/L.

Additional information

Short-term toxicity to fish:

The acute toxicity of Aluminium hydroxide diacetate hydrate on Zebrafish (Danio rerio) was evaluated according to OECD guideline 203 (reference 6.1.1-1). A limit test was performed in which the test animals were exposed to aqueous test media containing the test item for 96 hours at the limit of its solubility in the test medium (i.e. saturation) plus a control in order to demonstrate that the test item is not toxic to Zebrafish up to at least the saturation concentration. In the limit test a single concentration at saturation corresponding to 100 mg/L nominal concentration of the test item was used. The concentration of the saturated test solution was analytically determined to be 1.46 mg/L (calculated as the geometric mean of start and end concentrations). Fish were exposed to aqueous test media containing the test item for 96 hours in a static test. Ten fish were exposed to the test concentration or run as control (no replicates were used). Fish were observed at approximately 4, 24, 48, 72 and 96 hours after start of the test for signs of intoxication and mortality.

Mortality and any sub-lethal effects were not observed during the 96-h exposure period either in the treated or in the control group. Accordingly, the 96-h NOEC was determined as 1.46 mg/L (equivalent to 100 mg/L nominal concentration). The LOEC and the LC50 values were determined to be higher than 1.46 mg/L (equivalent to > 100 mg/L nominal concentration). Based on the molecular weight the recalculated NOEC for the anhydrous substance is 1.31 mg/L. The LOEC and the LC50 for the anhydrous substance was calculated to be higher than 1.31 mg/L. All validity criteria were met.

Short-term toxicity to invertebrates

In the acute immobilisation test (reference 6.1.3-1) with Daphnia magna (STRAUS), the effects of the test item were determined according to OECD Guideline for testing of chemicals, Guideline No. 202, adopted 13th April 2004. The study was conducted in a static system as a limit test over a period of 48 hours with a nominal concentrations of 100 % v/v saturated solution (corresponding to geometric measured concentrations of 0.96 mg/L. The validity criteria of the test guideline were fulfilled. The 48-h EC50 value was determined to be >0.96 mg/L (hydrated substance) and >0.86 mg/L (calculated for anhydrous substance). The 48-h NOEC was determined to be 0.96 mg/L (hydrated substance) and  0.86 mg/L (calculated for anhydrous substance).

Toxicity to aquatic algae:

The effect of the test item on the growth of a unicellular green algal species Raphidocelis subcapitata was determined according to OECD 201, Regulation (EC) No. 226/2016 Method C.3 and EPA OPPTS 850.5400 and under GLP (reference 6.1.5-1). The study was conducted under static conditions with an initial cell density of 1x10^4 cells/mL for a period of 72 hours. A stock solution of 100 mg/L was freshly prepared with OECD medium and shaken overnight and the non-dissolved test material was separated by filtration. Six concentrations were tested in a geometrical series with a dilution factor of 2: 6.25, 12.5, 25, 50 and 100 % v/v saturated solution (corresponding to 0.34, 0.42, 0.76, 0.84 and 1.30 mg/L (calculated geometric mean concentrations)).The EC50 values for inhibition of growth rate (ErC50) was 1.02 mg/L (hydrated substance) and 0.92 mg/L (calculated value for anhydrous substance) and for inhibition of yield (EyC50) 0.90 mg/L (hydrated substance) and 0.81 mg/L (calculated value for anhydrous substance). The EC10 value was determined to be 0.72 mg/L (hydrated substance) and 0.66 mg/L (calculated value for anhydrous substance) based on growth rate (ErC10) and 0.44 mg/L (hydrated substance) and 0.40 mg/L (calculated value for anhydrous substance) based on yield (EyC10).

Toxicity to miroorganisms:

The influence of the test item Aluminium hydroxide diacetate hydrate on the activity of the activated sludge was evaluated by measuring the respiration rate under defined conditions according to OECD guideline 209 and EU method C.11 (reference 6.1.7-1).The respiration rates (total, heterotrophic and nitrification oxygen uptake rates) of samples of activated sludge fed with synthetic sewage were measured in an enclosed cell containing an oxygen electrode after a contact time of 3 hours. Three test item concentrations (10, 100 and 1000 mg/L) were selected in accordance with the referred OECD 209 Guideline to demonstrate a possible significant inhibition of oxygen consumption to necessitate a subsequent definite test or demonstrate the absence of significant toxic effect (examined by 2 Sample t-Test) up to the highest examined test item concentration of 1000 mg/L. Defined amounts of the test item were added (measured) directly into the test vessels. In parallel with the test item treatments 3,5-dichlorophenol as positive reference control in concentrations of 2, 7 and 24.5 mg/L; furthermore blank (inoculum) control, nitrification controls and abiotic controls were investigated. The observed oxygen consumption rates and consequently the specific respiration rates in all examined test item concentrations remained in the range of the blank controls, no inhibitory effect of the test item was observed. The specific respiration rates did not differ statistically significantly from that of the control at the concentration of 1000 mg/L (2 Sample t-Test; (α=0.05)). The test was performed including abiotic controls. The abiotic controls were investigated at the test item concentration of 1000 mg/L and no remarkable abiotic oxygen consumption was noticed.

Under the conditions of the performed Activated Sludge Respiration Inhibition Test, the EC10 and EC50 values of test item was determined as higher than 1000 mg/L. Based on the statistical evaluation in this test the NOEC was 1000 mg/L. This pre-test demonstrated the absence of inhibition of oxygen consumption of the test item up to and including the limit concentration of 1000 mg/L, therefore in line with OECD guideline 209 an additional definite test is not required. Based on the molecular weight the recalculated EC10 and EC50 for the anhydrous substance is higher than 900 mg/L and the NOEC for the anhydrous substance is 900 mg/L.