Tris(N-hydroxy-N-nitrosophenylaminato-O,O')aluminium

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June-August 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Test item name: RCX 15-116
- Batch number: 15047AE2
- Other name(s): NPAL
- Appearance/colour: solid/whitish
- Chemical name: aluminium-N-nitrosophenylhydroxylamine (NPAL)
- CAS number: 15305-07-4
- Purity analysed: 99.1 %
- Molecular weight 438.3 g/mol
- Issue date of certificate: 08 Feb 2016
- Expiry date: 30 Nov 2016
- Stability: instable after repeated contact to air and / or light, undergoes hydrolysis
- Storage conditions: room temperature, protected from light

Analytical monitoring:

yes

Details on sampling:

Analytical samples taken at 0 hours (initial value) and 24 hours from fresh and aged test solutions were analysed from control, solvent control and all test item concentrations. Additionally the acetone stock solutions after 0 and 24 hours fresh were analysed.

Vehicle:

yes

Details on test solutions:

A semi-static main test with nominal concentrations of 5.00, 2.27, 1.03, 0.470 and 0.213 mg/L, solvent control and control was performed.

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna Straus, Clone V, was used as the test organism. The animals are continuously bred in the laboratory and were originally purchased in a healthy condition from the Federal Environment Agency in Berlin/Germany.

Daphnia magna was bred as single culture (1 daphnid per 100 mL) in Elendt M4 medium. The pHvalue of the aerated water was within a range of 6.0 – 9.0. The dissolved oxygen was above 60 % saturation and the total hardness 140 - 250 mg/L (as CaCO3), corresponding to 7.8 - 14°dH. The animals were fed with single cell green algae (Desmodesmus subspicatus, formerly Scenedesmus subspicatus) at least three times a week. The daphnids were reared at a temperature of 20 ± 2 °C in a climatic chamber with 16 hours of illumination and 8 hours of darkness. The medium was changed three times per week. A pipette was used to separate the young daphnids from the adults. Freshly hatched daphnids less than 24 hours old were used for the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

The total hardness (as CaCO3) of the untreated control was determined to be 13°dH (232 mg/L CaCO3).

Test temperature:

The mean temperature of the control and all test item concentrations was measured to be 20.6 ± 1.0 °C.

pH:

The mean pH-value of the untreated control was determined to be 7.46 ± 0.23.

Dissolved oxygen:

The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in all test units. In this test, the dissolved oxygen concentration was ≥ 7.9 mg/L.The mean oxygen concentration was determined to be 8.5 ± 0.4 mg/L.

Salinity:

No data.

Conductivity:

No data.

Nominal and measured concentrations:

A semi-static main test with nominal concentrations of 5.00, 2.27, 1.03, 0.470 and 0.213 mg/L, solvent control and control was performed. The measured initial concentration of the stock solutions ranged from 34 % to 95 % of nominal with a mean initial concentration of 61 % of nominal. Therefore toxicological endpoints were evaluated using the nominal concentrations of the test item.

Details on test conditions:

The daphnids were exposed to a range of test item concentrations, a solvent and a control for 48 hours. The test concentrations were chosen based on a non-GLP range-finding test. Two concentrations of the reference item potassium dichromate (1.0 mg/L, 2.0 mg/L) were tested around the same time period as the study.

Test procedure: semi-static
Duration: 48 hours
Temperature: 19.5 – 21.9 °C
Oxygen concentration: ≥ 7.9 mg/L
pH-value: 7.28 – 8.05
Exposure to light: 16 hours photoperiod /8 hours darkness daily
Feeding: none
Test vessels: four 100 mL glass beakers per concentration, each filled with 50 mL, one additional replicate for measurements without test organisms
Loading: 10 mL of test solution for each animal
Aeration: none
Number of animals: 20 per concentration in 4 replicates of 5

Reference substance (positive control):

yes

Remarks:

Two concentrations of the reference item potassium dichromate (1.0 mg/L, 2.0 mg/L) were tested around the same time period as the study.

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

4.22 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.535 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

0.47 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

After 24 hours of exposure no immobilisation was observed in the control and solvent control. No immobilisation higher than the allowed control immobilisation was observed at 0.213 mg/L and 0.470 mg/L. 25 % of the daphnids were immobile at 1.03 mg/L. 40 % immobilisation was observed at 2.27 mg/L and 50 % at the highest test item concentration of 5.00 mg/L. After 48 hours of exposure no immobilisation was observed in the control and solvent control. 15 % immobilisation was observed at 0.213 mg/L and 25 % immobilisation was observed at 0.470 mg/L. At the three highest test item concentration of 1.03, 2.27 and 5.00 mg/L all daphnids were immobile.

Reported statistics and error estimates:

The 24 h and 48 h EC50 are the estimated concentrations where 50 % of the daphnids were immobilised after 24 and 48 hours, respectively. The values for EC50 were determined by Weibull analysis using max linear likelihood regression. The evaluation of data was performed by ToxRat Professional 3.2.1. The NOEC was established based on the highest concentration at which the immobilisation is not higher than the allowed control immobilisation (≤ 10 % immobilisation).

Validity criteria fulfilled:

yes

Conclusions:

The EC50 (48 h) was determined to be 0.535 mg/L (nominal). The corresponding NOEC (48 h) could not be determined.

Executive summary:

The objective of this study was to determine the immobilisation effect of the test item on the water flea Daphnia magna, the No-Observed-Effect-Concentration (NOEC) and the Effect median Concentration (EC50). Twenty organisms per test concentration (4 replicates of 5 animals each) were used. The duration of the test was 48 hours. Endpoints reported are the EC50 and the NOEC after 24 and 48 hours. A semi-static main test with nominal concentrations of 5.00, 2.27, 1.03, 0.470 and 0.213 mg/L, solvent control and control was performed.

According to the results of the test, the EC50 (48 h) was determined to be 0.535 mg/L (nominal). The corresponding NOEC (48 h) could not be determined.

Description of key information

The EC50 (48 h) was determined to be 0.535 mg/L (nominal). The corresponding NOEC (48 h) could not be determined.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.535 mg/L