Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Version / remarks:
Adopted April 13, 2004
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: At the end of the exposure period, the replicates were pooled at each concentration before sampling.
- Sampling method:
Frequency at t=0 h and t=48 h
Volume 2.0 mL from the approximate centre of the test vessels
- Sample storage conditions before analysis: Samples were stored in a freezer (≤-15°C) until analysis at the analytical laboratory of the Test Facility.

Test solutions

Vehicle:
yes
Remarks:
water
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The batch of 3,4-dihydro-2,4-dioxo-1,3-2h-benzoxazine tested was a white powder with a purity of approximately 99% which was completely soluble in test medium at the concentrations tested. No correction was made for the purity/composition of the test item.
Preparation of test solutions started with the highest concentration of 100 mg/L applying one hour of magnetic stirring followed by a 20-minute treatment period of ultrasonic waves to accelerate dissolution of the test item in medium. Only a few floating undissolved particles were observed in the highest test concentration, however they were considered negligible which was confirmed in the analytical analysis of the test solutions (measured concentration = 99.2 mg/L). Lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. All test solutions were clear and colorless at the end of the preparation procedure.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Water flea
- Strain/clone: In-house laboratory culture with a known history.
- Justification for species other than prescribed by test guideline: This system has been selected as an internationally accepted invertebrate species.
- Source: In-house laboratory culture with a known history.
- Age of parental stock (mean and range, SD): <4 weeks
- Feeding during test: no
- Food type: /
- Amount: /
- Frequency: /

ACCLIMATION
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: Daily, a suspension of fresh water algae

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Test temperature:
19-20°C
pH:
7.4-8.1
Dissolved oxygen:
7.5-8.4 mg/L
Nominal and measured concentrations:
0.10, 1.00, 10 and 100 mg/L.
The measured concentrations were at the level of nominal throughout the test duration (94-96%).
Details on test conditions:
TEST SYSTEM
- Test vessel: 60 mL, all-glass
- Type (delete if not applicable): static
- Aeration: No aeration of the test solutions.
- No. of organisms per vessel: 5 per vessel containing 50 mL of test solution
- No. of vessels per concentration (replicates): 4 for the control and the highest test concentration.
2 per intermediate test concentration.
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
M7, as prescribed by Dr. Elendt-Schneider (Elendt, B.-P., 1990: Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus. Protoplasma 154, 25-33).

Composition of medium M7:
Adjusted ISO medium: the following chemicals (analytical grade) are dissolved in tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands):
Macro salts: CaCl2.2H2O 211.5 mg/L
MgSO4.7H2O 88.8 mg/L
NaHCO3 46.7 mg/L
KCl 4.2 mg/L
Medium M7: trace elements, macronutrients and vitamins are added to freshly prepared ISO medium to reach the following concentrations:
Trace elements:
B 0.125 mg/L
Fe 0.05 mg/L
Mn 0.025 mg/L
Li, Rb and Sr 0.0125 mg/L
Mo 0.0063 mg/L
Br 0.0025 mg/L
Cu 0.0016 mg/L
Zn 0.0063 mg/L
Co and I 0.0025 mg/L
Se 0.0010 mg/L
V 0.0003 mg/L
Na2EDTA.2H2O 2.5 mg/L
Macro nutrients:
Na2SiO3.9H2O 10.0 mg/L
NaNO3 0.27 mg/L
KH2PO4 0.14 mg/L
K2HPO4 0.18 mg/L
Vitamins: Thiamine 75.0 µg/L
B12 1.0 µg/L
Biotin 0.75 µg/L
The hardness: 180 mg/L expressed as CaCO3 and the pH: 7.7 ± 0.3.


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: A daily photoperiod of 16 hours
- Light intensity: not specified

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobility (including mortality) At 24 hours and at 48 hours.
pH and Dissolved oxygen At the beginning and at the end of the test, for the highest concentration and the control.
Temperature of medium Continuously in a temperature control vessel, beginning at the start of the test.


VEHICLE CONTROL PERFORMED: yes (medium)

RANGE-FINDING STUDY
- Test concentrations: 0.10, 1.00, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: combined limit/range-finding study
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
> 88 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: corresponds to nominal concentration of 100 mg/L
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 88 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: corresponds to nominal concentration of 100 mg/L
Results with reference substance (positive control):
The actual responses in this reference test with K2Cr2O7 are within the ranges of the expected responses at the different concentrations, i.e. the 48h-EC50 was between 0.3 and 1.0 mg/L. Hence, the sensitivity of this batch of D. magna was in agreement with the historical data collected at Charles River Den Bosch.

The 48h-EC50 was 0.59 mg/L with a 95% confidence interval between 0.53 and 0.72 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
In conclusion, the 48h-EC50 for Daphnia magna exposed to 3,4-dihydro-2,4-dioxo-1,3-2h-benzoxazine was beyond the range of concentrations tested, i.e. exceeded an average exposure concentration of 88 mg/L (nominal concentration of 100 mg/L).
Executive summary:

The objective of the study was to evaluate 3,4-dihydro-2,4-dioxo-1,3-2h-benzoxazine for its ability to generate acute toxic effects on the mobility of Daphnia magna during an exposure period of 48 hours and, if possible, to determine the EC50at 24 and 48 hours of exposure.

The study procedures described in this report were based on the OECD guideline No. 202, 2004.

The batch of 3,4-dihydro-2,4-dioxo-1,3-2h-benzoxazine tested was a white powder with a purity of approximately 99% which was completely soluble in test medium at the concentrations tested.

A combined limit/range-finding test was performed. Twenty daphnids per group (5 per replicate, quadruplicate) were exposed to an untreated control and to a nominal concentration of 100 mg/L, in a limit test. In addition ten daphnids per group (5 per replicate, duplicate) were exposed to nominally 0.10, 1.0 and 10 mg/L in the combined range-finding test. The total exposure period was 48 hours and samples for analytical confirmation of exposure concentrations were taken at the start and at the end of the test.

Samples taken from the limit concentration were analysed. The measured concentration at the start of the test was 99 mg/L and had decreased to 79% relative to nominal at the end of the test. Based on these results, effect parameters were expressed in terms of the average exposure concentration, calculated to be 88 mg/L.

No immobility was observed in the control and at any of the test concentrations throughout the exposure period.

The study met the acceptability criteria prescribed by the study plan and was considered valid.

In conclusion, the 48h-EC50for Daphnia magna exposed to 3,4-dihydro-2,4-dioxo-1,3-2h-benzoxazine was beyond the range of concentrations tested, i.e. exceeded an average exposure concentration of 88 mg/L (nominal 100 mg/L).