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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2-Feb-2018 to 23-Feb-2018
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions

Data source

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

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Reference substance name:
Rosin, reaction products with acrylic acid
EC Number:
280-192-2
EC Name:
Rosin, reaction products with acrylic acid
Cas Number:
83137-13-7
Molecular formula:
N.A. - UVCB substance
IUPAC Name:
Rosin, reaction products with acrylic acid
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 646729
- Physical state: yellow to brownish solid
- Expiration date of the lot/batch: 19 November 2018
STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature

Sampling and analysis

Analytical monitoring:
yes
Remarks:
MTDID 28640 is a complex mixture, therefore Total Organic Carbon (TOC) analysis was used as a proxy for the chemical.
Details on sampling:
- Concentrations: All; sampled at test initiation, and at test termination.
- Sampling method: Aliquots from test initiation were collected from the bulk test solutions. Aliquots from test completion were collected from pooled volumes of each of the control and test solution replicates.
- Sample storage conditions before analysis: Samples were collected in glass containers and stored refrigerated (2°C to 8°C) until analysis.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
- Method:Test solutions were prepared as water soluble fractions (WAFs) individually by adding the weighed amount of MTDID 28640 to approximately 800 mL of dilution water (test medium), then adding additional dilution water to bring the volume to 1.8 L. The control was prepared in a similar manner; however, no MTDID 28640 was added. Each solution was stirred using a stir plate and stir bar to create a vortex (~15%) and covered to reduce contaminants. Stirring occurred for approximately 92 hours. Solutions were then filtered through a 0.45 µm membrane filter in a glass vacuum filtration apparatus.
- Controls: Negative (Lab) Control: Blank test medium; Negative (Procedural) Control: Blank test medium prepared as WAF test solutions
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): At the time of preparation, test item WAFs appeared clear and colorless with visible, undissolved MTDID 28640 spinning in the water column, sitting on the surface of the water, and a small amount up the sides of the beaker due to surface tension. After the 92 hour stirring period, there was no change in appearance with the exception of the 100 mg/L loading rate which began to appear cloudy at the ~44 – 48 hr observation point. After filtration, all test solutions and controls appeared clear and colorless. Test solutions and controls appeared clear and colorless at test inititation and remained consistently clear and colorless throughout the test.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Water flea
- Source: In-house culture; original culture was obtained from Aquatic BioSystems (Fort Collins, CO) on April 18, 2017
- Age at study initiation: neonates < 24 hours old.
- Culturing: Daphnids were cultured in water from the same source as used during the test. 9.8% mortality was observed in daphnid cultures in the 7 days prior to the test. Daphnid cultures were fed approximately 4.0 mL of Pseudokirchneriella subcapitata (PKS) and 1.0 mL of yeast-cereal-grass fermented trout chow (YCT) three times per week. The neonates used in the test were fed approximately 5.0 mL of P. subcapitata prior to test initiation. The PKS and YCT used for feeding were also obtained from Aquatic BioSystems.
FEEDING DURING TEST
- Food type: Not fed during test

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
100 mg/L as CaCO3
Test temperature:
19.0 °C to 20.4 °C
pH:
8.0 to 8.2
Dissolved oxygen:
5.8 mg/L to 9.1 mg/L - Test Initiation
9.0 mg/L to 9.1 mg/L - Test Completion
Conductivity:
321 µS/cm to 326 µS/cm
Nominal and measured concentrations:
Nominal; 0 mg/L, 6.25 mg/L, 12.5 mg/L, 25 mg/L, 50 mg/L, 100 mg/L
Measured (mean TOC); 0.96 mg TOC/L, 2.32 mg TOC/L, 3.86 mg TOC/L, 6.72 mg TOC/L, 9.36 mg TOC/L, 7.83 mg TOC/L,
Details on test conditions:
TEST SYSTEM
- Test vessel: 250 mL glass beakers, 200 mL fill volume, covered with plexiglass, and preconditioned with appropriate test solution
- Aeration; control/dilution water aerated before use in test
- No. of organisms per vessel: five
- No. of vessels per concentration: four
- No. of vessels per control: four
TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Control/dilution water was a moderately hard, reconstituted water prepared from deionised water (Millipore system). To 200 L of deionised water, the following were added; 11.4401 g magnesium sulphate anhydrous, 13.2002 g calcium sulphate, 21.1202 g sodium bicarbonate, 0.8801 g potassium chloride, 100 mL of a 4 mg/L solution of Vitamin B12 and 400 mL of a 1 mg/L selenium solution (as sodium selenate solution).
- Intervals of water quality measurement: Dissolved oxygen, temperature, and pH at test initiation and test completion. Conductivity at test initiation only.
OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h:8h
- Light intensity: 528 - 566 lux
EFFECT PARAMETERS MEASURED: Immobilization at 24h, and 48h; At test completion, the immobilised daphnids were examined under a microscope to confirm if they were dead; in absence of a heartbeat.
RANGE-FINDING STUDY
- Test concentrations: 0, 0.1, 1.0, 10, and 100 mg MTDID 28640/L.
- Results used to determine the conditions for the definitive study: yes
Reference substance (positive control):
yes
Remarks:
zinc sulphate heptahydrate (CAS# 7446-20-0)

Results and discussion

Effect concentrations
Key result
Duration:
48 h
Dose descriptor:
EL50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
- Mobility:see Table 2
- Poor dose response (mobility) observed for nominal concentrations
- Mobility of control: No immobilization observed
Results with reference substance (positive control):
- Results with reference substance valid? Yes
- Dose-response test: Yes
- ECx: 48-hr LC50 = 0.89 mg/L (95% CI, 0.64 mg/L to 2.35 mg/L)
- Other: The sensitivity of Daphnia magna originating from the batch used in this test, for zinc sulphate fell within the expected range of sensitivity observed previously (2 SD range of mean; 0.22 to 1.01 mg/L). The reference substance test was conducted with a month (11 days) after initiation of the testing of MTDID 28640.
Reported statistics and error estimates:
Statistical analysis not required for determination of the EL50 for MTDID 28640.

Any other information on results incl. tables

Table 2. Observed immobilization

Nominal

loading rate

(mg/L)

Cumulative No.

Immobilized/Exposed

at 24 hrs

Cumulative No.

Immobilized/Exposed

at 48 hrs

Mean Immobilization

at 48 hrs (%)

0 (Lab Control) 0/0 0/0  0
0 (Procedural Control) 0/0 0/0  0
6.25 0/0 0/0 0
12.5 0/0 4/20  20
25 0/0 3/20 15
50  0/0 10/20 50
100 0/0 6/20 30

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
The validity criteria of OECD TG 202 were fulfilled. Control immobilization was < 10% at the end of the test. The dissolved oxygen concentration was ≥ 3 mg/L in the control and test vessels at the end of the test.
Conclusions:
The 48-hour EL50 of MTDID 28640 to Daphnia magna was >100 mg/L, based on nominal loading rates (OECD TG 202).
Executive summary:

The 48-hour EL50 of MTDID 28640 to Daphnia magna was examined in a static test conducted according to OECD TG 202. Results are based on nominal concentrations, with test solutions prepared as individual water accommodated fractions (WAFs). Undissolved MTDID 28640 was observed at all non-control test loading rates before filtration. Because MTDID 28640 is a complex mixture, Total Organic Carbon (TOC) was analyzed as a proxy for the chemical. TOC concentrations in test solutions were consistent (± 20%) between samples from test initiation and from test completion. No immobilization was observed in the control samples or at the 6.25 mg/L loading rate after 48 hours. The following immobilization levels were observed at other loading levels; at 12.5 mg/L, 20%, at 25 mg/L, 15%, at 50 mg/L, 50%, at 100 mg/L, 30%.  The lack of dose response in this test led to the conclusion that the 48-hour EL50 is >100 mg/L, based on the nominal loading rate.

The test was conducted according to internationally accepted test guidelines and was GLP compliant. It is reliable with restrictions and suitable for Risk Assessment, Classification and Labeling, and PBT Analysis.