2-acetyl-3-(4-hexadecoxyphenyl)-1,4-benzoquinone

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:

2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Adopted April 13, 2004

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-acetyl-3-(4-hexadecoxyphenyl)-1,4-benzoquinone

EC Number:

947-565-8

Molecular formula:

C30 H42 O4

IUPAC Name:

2-acetyl-3-(4-hexadecoxyphenyl)-1,4-benzoquinone

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. In addition, the filter containing the undissolved residue was kept for possible analysis.

Test solutions

Vehicle:

yes

Remarks:

water

Details on test solutions:

The batch of V134434 tested was an orange-red powder with a purity of >95 mol% which was not completely soluble in test medium at the loading rates initially prepared. No correction was made for the purity/composition of the test item.
Preparation of test solutions started with loading rates individually prepared at 1.0, 10 and 100 mg/L. A three-day period of magnetic stirring was applied after 15 minutes of ultrasonic treatment to ensure maximum dissolution of the test item in medium. Thereafter, the aqueous Water Accommodated Fractions (WAFs) were collected by filtration through a 0.45 µm membrane filter (RC55, Whatman) and used as test concentrations. 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:

7.9-8.1

Dissolved oxygen:

8.8-9.1 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:
Salts: H3BO3 0.71 mg/L
FeSO4.7H2O 0.25 mg/L
MnCl2.4H2O 0.090 mg/L
LiCl 0.076 mg/L
RbCl 0.018 mg/L
SrCl2.6H2O 0.038 mg/L
Na2MoO4.2H2O 0.015 mg/L
NaBr 0.0040 mg/L
CuCl2.2H2O 0.0042 mg/L
ZnCl2 0.013 mg/L
CoCl2.6H2O 0.010 mg/L
KI 0.0032 mg/L
Na2SeO3 0.0022 mg/L
NH4VO3 0.00057 mg/L
Na2EDTA.2H2O 0.62 mg/L
Na2SiO3.5H2O 7.5 mg/L
NaNO3 0.27 mg/L
KH2PO4 0.14 mg/L
K2HPO4 0.18 mg/L
Vitamins: Thiamine hydrochloride 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 concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 0.46 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 0.46 mg/L = considered the maximum soluble concentration of test item in test medium

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.46 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 0.46 mg/L = considered the maximum soluble concentration of test item in test medium

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 V134434 was beyond the range of concentrations tested, i.e. exceeded an average exposure concentration of 0.46 µg/L, being considered the maximum soluble concentration of test item in test medium.

Executive summary:

The objective of the study was to evaluate V134434 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.In addition, procedures were based on the test methods described in the OECD series on testing and assessment number 23, 2000.

The batch of V134434 tested was an orange-red powder with a purity of >95 mol% which was not completely soluble in test medium at the loading rates initially prepared.Water Accommodated Fractions (WAFs) were individually prepared at loading rates ranging between 1.0 and 100 mg/L and used as test concentrations.

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 WAF prepared at a loading rate of 100 mg/L, in a limit test. In addition ten daphnids per group (5 per replicate, duplicate) were exposed to WAFs prepared at loading rates of 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.

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

Samples taken from the limit concentration were analysed. Test item responses measured in the samples taken from the WAF prepared at a loading rate of 100 mg/L were below the Limit of Quantification (i.e. LOQ = 1 µg/L). Hence, actual exposure concentrations were estimated by extrapolation of the calibration curve. The measured concentration at the start of the test was determined to be 0.52µg/L at the WAF prepared at a loading rate of 100 mg/L. During the exposure period, the initial concentration had decreased to 0.40µg/L, i.e. 78% relative to initial.

Based on this result, effect parameters were expressed in terms of the average exposure concentration calculated to be 0.46µg/L at the limit concentration.

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

In conclusion, the 48h-EC₅₀for Daphnia magna exposed to V134434 was beyond the range of concentrations tested, i.e. exceeded an average exposure concentration of 0.46 µg/L being considered as the maximum soluble concentration of test item in test medium.