2-ethylhexyl salicylate

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 June 2021 - September 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

2012

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Batch number of test material: 10701776
- Purity: 99.89%
- Appearance: Colorless to pale yellow, clear liquid

Analytical monitoring:

yes

Details on sampling:

At the sampling timepoint during the Biological-Phase of the study, about 10 mL of each test sample was sampled (weighed to determine the exact volume sampled) and exactly the same volume of acetonitrile was added, leading to a dilution factor of 2. The samples were analyzed directly after sampling to have a constant follow-up of the dosage of the test item in the flow-through system. The remaining diluted samples were stored frozen (at -20 ± 5°C).

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: For the preparation of the four application solutions used for the dosage of the highest test item concentration, 167 mg (167.02 – 167.32 mg) of the test item were dissolved in 100 mL DMF. This application solution was diluted with adequate amounts of DMF to prepare the application solutions used for dosage of the test media with lower test item concentrations. All application solutions were stirred for 10 minutes at room temperature. The application solutions were freshly prepared every seven days. The stability of the test item in the DMF application solutions during their use of 7 days was verified in a pre-experiment (non GLP) within a different study with the test item.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): DMF
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): 60 µL/L
- Test concentration separation factor: 2
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Straus
- Age at study initiation (mean and range, SD): < 24 hours
- Method of breeding: Bred in IES Ltd Laboratories in culture medium identical to the medium used for the test. The temperature and light conditions were identical to those of the tests.
- Source: clone originally from the Daphnia Collection of the University of Basel/Switzerland in 2015
- Age of parental stock (mean and range, SD): at leasst 14 days old, but no older than four weeks and were not first brood progeny.
Feeding during test:
- Food type: green algae of the species Desmodesmus subspicatus
- Amount: 0.4 mg C/L (test start) up to 0.8 mg/L (from day 7 onwards)
- Frequency: continuously

Test type:

flow-through

Water media type:

other: Reconstituted water (Elendt M7 medium) according to OECD 211

Limit test:

no

Total exposure duration:

21 d

Hardness:

2.5 mmol/L

Test temperature:

20 - 21°C

pH:

7.8 - 8.1

Dissolved oxygen:

at lease 8 mg/l

Salinity:

Alkalinity: 0.9 mmol/L

Nominal and measured concentrations:

Nominal: 0.00625 mg/L; 0.0125 mg/L; 0.025 mg/L; 0.050 mg/L; 0.10 mg/L
Mean measred: 0.0032 mg/L; 0.0061 mg/L; 0.014 mg/L; 0.028 mg/L; 0.05 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Flow-through glass beakers containing 50 mL of test medium
- Type (delete if not applicable): The outlet of the vessels was fitted with a stainless-steel net to retain the parental daphnids and the offspring in the test vessel. The test vessel was covered with a funnel which directed the new test medium (dropping from above) to the bottom of the test vessel.
- Aeration: no
- Type of flow-through (e.g. peristaltic or proportional diluter): flow-through
- Renewal rate of test solution (frequency/flow rate): 12-fold water exchange per day
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10
- No. of vessels per vehicle control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M7 medium according to guideline
- Water hardness: 2.5 mmol/L (= 250 mg/L as CaCO3)

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16-hour light to 8-hour dark cycle with a 30-minute transition period
- Light intensity: between approximately 8.2 and 10.6 µmol m-2 s-1

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
The test replicates were observed daily for immobility of adults or other visible abnormalities.
On the same dates, the test replicates were observed for the number of living and dead offspring and for the presence of aborted eggs.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
Range finding study:
- Test concentrations: 0.020 mg/L, 0.10 mg/L, 0.15 mg/L
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

0.008 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: 95% confidence interval: 0.0060 - 0.019 mg/L

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.006 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

0.014 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence interval: 0.008 - 0.025

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.014 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Body length:
The EC10 for mean body length was determined to be 0.045 mg/L (mean measured concentration).
- Behavioural abnormalities:
With the exception of the reported toxic effects, no visible abnormalities were observed at the daphnids during the test (also no aborted eggs observed).

Reported statistics and error estimates:

The results obtained from the solvent control were tested for statistically significant differences compared to the control by Student t-test or Welch t-test, where appropriate. As control and solvent control were not found to be statistically significantly different, the controls were pooled for further statistical analysis.
Mortality/Immobility: Cochran-Armitage test., two sided, α = 0.05
Reproduction rate: Williams t-test, one-sided smaller, α = 0.05;
Body length: Dunnett’s t-test Procedure, one-sided smaller, α = 0.05

Validity criteria fulfilled:

yes

Conclusions:

The EC10 for the reproductive output is 0.0084 mg/L showing that the test item is very toxic to Daphnia magna.

Description of key information

EC10 (reproduction) = 0.0084 mg/L (based on mean measured concentrations)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC10

Effect concentration:

0.008 mg/L

Additional information

A guideline study according to OECD 211 with Daphnia magna in a flow-through system with analytical measurements was conducted.

The EC10 for the reproductive output is 0.0084 mg/L showing that the test item is very toxic to Daphnia magna.