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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:

09 - 11 Mar 2020

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)

Version / remarks:

April 2004

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

2017

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Version / remarks:

April 1996

GLP compliance:

yes (incl. QA statement)

Remarks:

National Institute of Pharmacy and Nutrition, Budapest, Hungary (date of issue: 03 August 2018)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Control and 100 mg/L
- Sampling method: Duplicate samples were taken (2 x ~15 mL from three replicates) at the beginning and at the end of the renewal periods from the control and at the applied test concentration level.
- Sample storage conditions before analysis: Samples were frozen and kept approximately at -20 °C at the Test Facility. One set of the samples was sent to the Test Site for analysis and one set was retained as a back-up at the Test Facility.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Because the test item is a UVCB with very poor solubility, test solution was prepared using a saturated solution method according to the Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, OECD No. 23. A saturated test item solution (nominal loading rate of 100.0 mg/L) was prepared by dispersing/dissolving the amount of test item into the test medium (ISO Medium) two days before the start of the experiment. This solution was shaken for about 24 hours at approximately 30°C and then equilibrated for about 24 hours at approximately 20°C. The non-dissolved test material was removed by filtration through a fine (0.22 µm) filter to give the appropriate WAF solution. The maximum amount of test material in the medium was exposed applying this procedure. Prior to treatment of each renewal period, test item solution was prepared by the method described above. The test solution was prepared just before introduction of the Daphnia (start of the treatments).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Age at study initiation (mean and range, SD): < 24 h
- Stage and instar at study initiation: juveniles
- Method of breeding: The Daphnia are bred in Ecotoxicological Laboratory of Charles River Laboratories Hungary Kft.
- Source: István Szent University, 2100 Gödöllő, Páter Károly u. 1, Hungary
- Feeding during test : No

ACCLIMATION
- Acclimation period: None

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

244 mg/L as CaCO3

Test temperature:

20.5 – 20.8 °C

pH:

7.78 – 7.89

Dissolved oxygen:

7.1 – 8.7 mg/L

Nominal and measured concentrations:

- nominal concentration: 100 mg/L nominal loading rate WAF
- mean measured concentration 0 h new: 0.256 mg/L
- mean measured concentration 24 h new: 0.256 mg/L
- mean measured concentrtaion 24 h old: 0.181 mg/L
- mean measured concentration 48 h old: 0.178 mg/L
- geometric mean: 0.214 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers
- Volume of solution: 50 mL
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): 24 h
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ISO water according to guideline
- Culture medium different from test medium: No
- Intervals of water quality measurement: water temperature, the oxygen concentrations and pH of the control and the test solution were measured at the beginning and at the end of the renewal periods

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 hours light/ 8 hours darkness

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- mobility was checked every 24 hours

RANGE-FINDING STUDY
- Test concentrations: 0.1, 1, 10, 100 mg/L nominal loading rate WAF
- Results used to determine the conditions for the definitive study: no significant toxicity was found in any of the test concentrations

Reference substance (positive control):

yes

Remarks:

Potassium dichromate is tested at least twice a year

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.214 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 0.214 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The biological results are mainly related nominal loading rate WAF, but expressed as both the nominal loading rate WAF and measured geometric mean test item concentration.

Results with reference substance (positive control):

- Last test with potassium dichromate (05 - 06 Mar 2020): The 24 h EC50: 0.87 mg/L, (95 % confidence limits: 0.70 – 0.99 mg/L)

Reported statistics and error estimates:

No statistical analysis was performed because of the lack of toxic effects.

Table 1:Number and percentage of immobilised daphnids

Test Group		Number of treated daphnids	Number of immobilised daphnids
			24 hours		48 hours
			number	percent	number	percent
Control		20	0	0	0	0
100.0 mg/L nominal loading rate		20	0	0	0	0

 

Table 2: Validity criteria

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the control containing the solubilising agent, not more than 10% of the daphnids should have been immobilized.	0%	Yes
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	≥7.1 mg/L	Yes

 

Validity criteria fulfilled:

yes

Remarks:

See table 2 at "any other information on results incl. tables".

Description of key information

Daphnia magna: 48-hour EC50 > 0.214 mg/L (geom. mean meas.) (OECD 202, 2004)

Daphnia magna: 48-hour NOEC >= 0.214 mg/L (geom. mean meas.) (OECD 202, 2004)

Additional information

The acute toxicity of Glycerides, C16-18 (even numbered) mono- and di- and their citrates (EC 701-358-7) to aquatic invertebrates was studied in a 48 hour semi-static limit test according to OECD guideline 202. Daphnids were exposed to a nominal loading rate of 100 mg/L (WAF). Analytical measurement resulted in measured concentrations of 0.256 mg/L at the start of the renewal period and a geometric mean concentration of 0.214 mg/L. The effect parameters were measured after 24 and 48 hours. No immobilisation was observed in the replicates of the test concentration and control at any time of the test period. Therefore the EC50 value after 48 h was determined to be > 0.214 mg/L. The result is based on the geometric mean measured test concentrations of the test substance.