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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
the study does not need to be conducted because a long-term aquatic toxicity study on invertebrates is available
Cross-reference
Reason / purpose for cross-reference:
data waiving: supporting information
Reference
Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1988-12-02 - 1988-12-23 (experimental phase)
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study without detailed documentation
Remarks:
The study was conducted under GLP in accordance with a recognised guideline and the validity criteria were fulfilled. However, the report omits some procedural details.
Qualifier:
according to guideline
Guideline:
other: OECD 202 Part II (1984)
Version / remarks:
OECD Guideline for Testing of Chemicals Nr. 202 "Daphnia sp. Acute Immobilisation Test and Reproduction Test" Part II - the reproduction test (at least 14 days) Adopted: April 4, 1984
Deviations:
no
Principles of method if other than guideline:
Not relevant.
GLP compliance:
yes
Analytical monitoring:
yes
Details on sampling:
- Concentrations: 0,0020 mg/L, 0,0063 mg/L, 0,020 mg/L (on basis of total chromium) and control
- Sampling method: Samples of the freshly prepared media of all treatments and the control were taken on day 0, 7 and 10 and samples of the corresponding expired media were taken 72, 72 and 48 h later, on days 3, 10 and 12, respectively.
- Sample storage conditions before analysis: not stated
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution was prepared by dissolving 56.0 mg test substance (26 % Cr2O3) in a 5 L volumetric flask with double distilled water and adding up to the mark. The solution was filtered through a 0.45 pm membrane filter. The concentration was 2 mg/L Cr. To prepare the test media, 125 ml of additive was made up to the mark with dilution water in a 5 L volumetric flask and then transferred to an aquarium. Then the pH was adjusted with HCl and NaOH to 7.0 + 0.2 according to GLP. The 3 test concentrations were adjusted by adding 5, 15.75 and 50 ml of the stock solution, respectively. No stock addition was made to the control medium.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): The stock solution was membrane-filtered (45 micron pore diameter) before dosing the test system.
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna Straus, parthenogenic females
- Source: Test animals were taken from an in-house laboratory culture of the test facility, origiinally obtained from a clonal culture of the Bundesgesundheitsamt (Federal Health Authority), Berlin, Germany
- Age at study initiation (mean and range, SD): 6 to 24 h at test initiation
- Stage and instar at study initiation: neonates (< 24h)
- Feeding during test: Yes
- Food type: suspension of green algae (S. subspicatus) prepared from a concentrate derived from a fermenter culture. The concentrate was diluted 1:10 to achieve an extinction of 0.54 at 578 nm and treated with ultrasound for 5 minutes before feeding the Daphnia.
- Amount: days 0-1: 0.10 mL algal suspension/adult; days 2-3: 0.12 mL algal suspension/adult; days 4-5: 0.16 mL algal suspension/adult; days 6-7: 0.20 mL algal suspension/adult; days 8-20: 0.40 mL algal suspension/adult
- Frequency: daily

ACCLIMATION
- Acclimation period: not stated

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES, INCLUDING CULTURING CONDITIONS: The culture vessels were sieved and all juveniles removed one day before the start of the test (2:00 h p.m.). At the start of the test (8:00 h a.m.), the fresh juveniles were removed from the culture by sieving again and placed in the test vessels.
Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
21 d
Post exposure observation period:
Not relevant.
Hardness:
Not stated.
Test temperature:
19.7 to 21.7 degrees C in fresh media (all treatments)
19.6 to 20.6 degrees C in expired media (all treatments)
pH:
pH 6.9 to 7.3 in fresh media (all treatments)
pH 7.6 to 8.3 in expired media (all treatments)
Dissolved oxygen:
8.3 to 9.7 mg O2/L in fresh media (all treatments).
7.6 to 8.9 mg O2/L in expired media (all treatments).
Salinity:
Not relevant.
Nominal and measured concentrations:
nominal: 0,0020 mg/L, 0,0063 mg/L, 0,020 mg/L (on basis of total chromium) and a control
time weighted average: 0.0041, 0.0078 and 0.019 mg Cr/L (dissolved chromium)
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): beakers
- Material, size, headspace, fill volume: glass, 9.5 cm diameter, 11.5 cm tall, containing 250 mL test medim
- Aeration: No.
- Renewal rate of test solution (frequency/flow rate): All test media were renewed 3 times each week.
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 8 (initially 12; adults were examined microscopically on day 7, any males were substituted with females from the 4 'reserve' replicates and assessment of reproductive performance then continued with 8x replicates containing only adult females).
- No. of vessels per control (replicates): 8 (initially 12; adults were examined microscopically on day 7, any males were substituted with females in the 4 'reserve' replicates and assessment of reproductive performance then continued with 8x females)
- Biomass loading rate: 25 mL per adult daphnid

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Filtered surface water from a gravel pit in Leverkusen with addition of treated effluent from Buerrig community STP diluted at a ratio of 1:40.
- Culture medium different from test medium: Yes. Culture medium was treated Leverkusen drinking water.
- Intervals of water quality measurement: Three times each week, coinciding with media renewals, in all freshly prepared and aged test media.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: "according to season", i.e. short daylength (December 1988, Germany)
- Light intensity: 6 micro Einsteins (= 400 Lux)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortality, the day of first brood production as well as the reproduction rate were determined at least on each day of test medium renewal.

VEHICLE CONTROL PERFORMED: no (not relevant)

RANGE-FINDING STUDY
- Test concentrations: not stated.
- Results used to determine the conditions for the definitive study: not stated.
Reference substance (positive control):
no
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
> 0.02 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Remarks:
total chromium
Basis for effect:
mortality
Remarks:
of adults
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
> 0.02 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Remarks:
total chromium
Basis for effect:
mortality: Number of living offspring produced per surviving parental animal {for Daphnia magna, TG 211}
Remarks:
number of living offspring produced per surviving parental animal
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
> 0.02 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Remarks:
total chromium
Basis for effect:
mortality: Total number living offspring produced at the end of the test per parent daphnia at the start of the test excluding from the analysis parental accidental and/or inadvertent mortality {TG 211}
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
>= 0.02 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Remarks:
total chromium
Basis for effect:
mortality
Remarks:
of adults
Remarks on result:
other: The NOEC was the highest concentration tested.
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
>= 0.02 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality: Number of living offspring produced per surviving parental animal {for Daphnia magna, TG 211}
Remarks on result:
other: The NOEC was the highest concentration tested.
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
> 0.02 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality: Total number living offspring produced at the end of the test per parent daphnia at the start of the test excluding from the analysis parental accidental and/or inadvertent mortality {TG 211}
Remarks on result:
other: The NOEC was the highest concentration tested.
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
> 0.015 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
act. ingr.
Remarks:
total chromium
Basis for effect:
mortality
Remarks:
of adults
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
> 0.015 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
act. ingr.
Remarks:
: total chromium
Basis for effect:
mortality: Number of living offspring produced per surviving parental animal {for Daphnia magna, TG 211}
Remarks:
: number of juveniles per adult
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
> 0.015 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
act. ingr.
Remarks:
total chromium
Basis for effect:
mortality: Total number living offspring produced at the end of the test per parent daphnia at the start of the test excluding from the analysis parental accidental and/or inadvertent mortality {TG 211}
Key result
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
>= 0.015 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
act. ingr.
Remarks:
total chromium
Basis for effect:
mortality
Remarks:
of adults
Remarks on result:
other: The NOEC was the highest concentration tested.
Key result
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
>= 0.015 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
act. ingr.
Basis for effect:
mortality: Number of living offspring produced per surviving parental animal {for Daphnia magna, TG 211}
Remarks on result:
other: The NOEC was the highest concentration tested.
Key result
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
>= 0.015 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
act. ingr.
Basis for effect:
mortality: Total number living offspring produced at the end of the test per parent daphnia at the start of the test excluding from the analysis parental accidental and/or inadvertent mortality {TG 211}
Remarks on result:
other: The NOEC was the highest concentration tested.
Details on results:
- Behavioural abnormalities: none stated
- Observations on body length and weight: not determined
- Other biological observations: none stated
- Mortality of control: see table below
- Abnormal responses: The report mentions substitution of males identified on day 7 with females from reserve replicates, but numbers are not stated and the number of replicates was reduced from 12 to 8 replicates per tretament afterwards for the rest of the test duration.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: The stock solution of nominal 2 mg Cr dissolved in water was filtered through membranes (0.45 micron pore diameter) prior to further dilution and addition to the test vessels.
Results with reference substance (positive control):
Not relevant.
Reported statistics and error estimates:
Not relevant.
Validity criteria fulfilled:
yes
Conclusions:
The study was conducted under GLP according to OECD TG 202 Part II (1984) on the registered substance, without deviations which may have an impact on the validity of the study. Thus, the results were obtained via a scientifically reasonable method and the obtained results can be considered as reliable to assess the long-term toxicity of the test substance towards aquatic invertebrates.
In a semi-static test Daphnia magna (< 24h) were exposed to the test substance at the concentrations of nominal 0,0020 mg/L, 0,0063 mg/L, 0,020 mg/L (on basis of total chromium) and a control for a period of 21 days under defined conditions. Using AAS detection arithmetic mean measured concentrations of 0.0008, 0.0045 and 0.015 mg Cr/L (dissolved chromium) were determined. Based on the obtained results no effects were observed on the mortality and reproduction of the adults daphnids up to the highest concentration tested. The 21-day EC50 values for mortality and juvenile production per survived and inserted adult Daphnia were greater than 0.0200 mg total Cr/L, based on nominal concentrations, or greater than 0.015 mg Cr/L, based on time weighted, background-corrected, measured concentrations of dissolved chromium. The 21-day NOEC was determined to be ≥ 0.0200 mg total Cr/L, based on nominal concentrations, or greater than 0.015 mg Cr/L, based on time weighted, background-corrected, measured concentrations of dissolved chromium and the associated 21-day LOEC was determined to be > 0.0200 mg total Cr/L, based on nominal concentrations, or greater than 0.015 mg Cr/L, based on time weighted, background-corrected, measured concentrations of dissolved chromium for all relevant parameters, respectively.
Executive summary:

The chronic toxicity of the registered substance to Daphnia magna was studied under GLP according to OECD TG 202 Part II (1984).

Young daphnids (< 24h) were exposed to nominal concentrations of 4526, 6400, 9051 and 10000 mg/L for 21 days under semi-static conditions, with renewal of pH-adjusted media three times per week. A water control was tested in parallel and the pH, temperature as well as the content of dissolved oxygen was measured in all fresh and expired test media. For the test item concentrations as well as for the control 8 replicates with 5 daphnids were prepared. As effect parameters the mortality as well as the reproduction and any sublethal effect of the test animals was observed at least on each day of test medium renewal.

Using atomic absorbtion spectrometry (AAS) the concentrations of dissolved Chromium were determined in fresh and expired test media of all treatments and the control. After subtraction of the mean background concentration of chromium in the untreated control, mean measured concentrations of dissolved Cr were 0.0010, 0.0041 and 0.0144 mg Cr/L at nominal concentrations of 0.020, 0.0063 and 0.0200 mg/L, respectively.

Based on the obtained results,the test item concentrations were not within ± 20% of the nominal concentrations during the test. Therefore, time weighted average concentrations were calculated subsequently by the use of the background-corrected analytical recoveries of total Cr according to the formula presented in Annex 2 of the OECD TG 211 as recommended. Accordingly the following time weighted concentrations were determined:

0, 0.0008, 0.0045 and 0.015 mg/L

Due to the absence of treatment-related adult mortality or adverse impact on numbers of juveniles per inserted adult daphnid or survived adult daphnid, respectively, the mortality and reproductive EC50 (21d) values were greater than 0.0200 mg Cr/L, the highest nominal concentration tested. Based on time weighted, background-corrected concentrations, the mortality and reproductive EC50 (21d) values were > 0.015 mg Cr/L (measured). The 21-day NOEC was determined to be ≥ 0.0200 mg total Cr/L, based on nominal concentrations, or greater than 0.015 mg Cr/L, based on time weighted, background-corrected, measured concentrations of dissolved chromium and the associated 21-day LOEC was determined to be > 0.0200 mg total Cr/L, based on nominal concentrations, or greater than 0.015 mg Cr/L, based on time weighted, background-corrected, measured concentrations of dissolved chromium for all relevant parameters, respectively.

Data source

Materials and methods

Results and discussion

Applicant's summary and conclusion