1,1'-(1-phenylethane-1,1-diyl)bis[4-(heptyloxy)benzene]

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

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:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Batch No.of test material: 16020201
- Expiration date of the batch: 21/03/2021
- Purity: 99.56%
- Purity test date: 01/02/2016

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature
- Stability under test conditions: No data
- Solubility and stability of the test substance in the solvent/vehicle: No data
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: No data

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Control (blank), solvent control and nominal 0.010, 0.10, 1.0 and 10 ug/L test concentrations sampled 0 and 48h
- Sample storage conditions before analysis: All samples stored frozen (<= -15oC) until analysis. On the day of analysis, test samples were thawed to room temperature

Vehicle:

yes

Remarks:

Stock and test solutions prepared using dimethlformamide (DMF)

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A nominal 100 mg/L stock solutions in DMF (dimethlformamide) was prepared, nominal 0.10, 1.0 and 10 mg/L stock solution were prepared by dilution of 100 mg/L stock solution. Test solutions were prepared by addition of 100 uL of appropriate stock solution to 1 L slowly stirring test medium. All test solutions were stirred for approximately 25 mins prior to use.
- Eluate: M2 test medium, according to OECD guideline 201
- Differential loading: No
- Controls: The control contained blank test medium only. The solvent control contained 100 ul/L of DMF in test medium
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): DMF (dimethlformamide)
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): 100 ul/L

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: No data
- Justification for species other than prescribed by test guideline: Not applicable
- Source: In-house laboratory cultures, with a known history
- Age of parental stock (mean and range, SD): No more than 2 weeks old
- Feeding during test: None
- Food type: Not applicable
- Amount: Not applicable
- Frequency: Not applicable

ACCLIMATION
- Acclimation period: Not applicable
- Acclimation conditions (same as test or not): Not applicable
- Type and amount of food: Not applicable
- Feeding frequency: Not applicable
- Health during acclimation (any mortality observed): Not applicable

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Daphnia <24h old were used in the test

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

Not applicable

Hardness:

No data

Test temperature:

20oC, constant within 2oC

pH:

0h: 7.9-8.0
48h: 8.1

Dissolved oxygen:

>= 3 mg/L

Salinity:

No data

Conductivity:

No data

Nominal and measured concentrations:

Nominal concentrations: 0.010, 0.10, 1.0 and 10 ug/L plus control and solvent control
Measured concentrations: 15 ug/L (nominal 10 ug/L)

Details on test conditions:

TEST SYSTEM
- Test vessel: 60 mL, all glass
- Type (delete if not applicable): No data
- Material, size, headspace, fill volume:
- Aeration: No
- Type of flow-through (e.g. peristaltic or proportional diluter): Not applicable
- No. of organisms per vessel: 20 for blank control, solvent control and nominal 10 ug/L test solution, 10 for nominal 0.010, 0.10 and 1.0 ug/L test solutions
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4
- Biomass loading rate: No data

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M7 (adjusted ISO) test medium
- Total organic carbon: No data
- Particulate matter: No data
- Metals: No data
- Pesticides: No data
- Chlorine: No data
- Alkalinity: No data
- Ca/mg ratio: No data
- Conductivity: No data
- Salinity: No data
- Culture medium different from test medium: No
- Intervals of water quality measurement: No data

OTHER TEST CONDITIONS
- Adjustment of pH: Not applicable
- Photoperiod: 16 hours
- Light intensity: No data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobility observed at 24 and 48h

RANGE-FINDING STUDY
- Test concentrations: Nominal 1.0, 10 and 100% of saturated solution at 100 mg/L
- Results used to determine the conditions for the definitive study: Immobility observed was considered to be due to mechanical hampering (daphnids trapped in floating layer) rather than toxicity

Reference substance (positive control):

yes

Remarks:

Reference test using potassium dichromate performed 25 - 27 September 2017. Results were within limits of historical data collected at the test facility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

>= 15 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Nominal concn (ug/L	Geometric mean measured concn (ug/L)	Total no. organisms tested	Total no. immobilised		% effect
			24h	48h
Blank control	<LoD	20	0	0	0
Solvent control	<LoD	20	0	0	0
0.010	-	10	0	0	0
0.10	-	10	0	0	0
1.0	-	10	0	0	0
10	15	20	0	0	0

Validity criteria fulfilled:

yes

Conclusions:

The EC50, based on immobility, was determined to be >15 ug/L (based on geometric mean measured concentrations) under the conditions of the test. Due to the very low solubility of 4,4’-(1-phenylethane-1,1-diyl)bis(heptyloxybenzene) in the test medium, concentration levels that may be toxic for daphnids could not be reached.

Executive summary:

In a 48-h acute toxicity study the aquatic invertebrate, Daphnia magna, was exposed to a range of test concentrations under static conditions in accordance with the OECD test guideline 202 and in compliance with GLP. The nominal test concentrations were a control, a solvent control, 0.010, 0.10, 1.0 and 10 ug/L. Results were calculated on the basis of geometric mean measured test concentrations.

Under the conditions of the test, the EC50 (immobility) was determined to be >15 ug/L, based on geometric mean measured concentrations. Due to the very low solubility of 4,4’-(1-phenylethane-1,1-diyl)bis(heptyloxybenzene) in the test medium, concentration levels that may be toxic for daphnids could not be reached. The laboratory study report stated that the test item was not completely soluble in the test medium at the loading rate initially prepared.

This acute toxicity study is considered acceptable and satisfies the guideline requirements for a short-term toxicity study to aquatic invertebrates.

Description of key information

In a reliable (Klimisch 1) 48-h acute toxicity study the aquatic invertebrate, Daphnia magna was exposed to a range of test concentrations under static conditions in accordance with the OECD test guideline 202 and in compliance with GLP.

Under the conditions of the test, the EC50 (immobility) was determined to be >15 ug/L, based on geometric mean measured concentrations.

The EC50 value is greater than the limit of solubility of the test substance.

The test validity criteria were met and there were no significant deviations noted to affect the integrity of the study. This acute toxicity study is considered acceptable and satisfies the guideline requirements for a short-term toxicity study to aquatic invertebrates.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

15 µg/L