1,1'-(chlorophenylmethylene)bis[4-methoxybenzene]

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:

2017-11-09 to 2018-03-28

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:

13 April 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling: The samples were filled into 10 mL glass vials. To each vial, 5 mL acetonitrile was added and
samples were stored in the freezer (≤ -18 °C). The sampling was conducted according to the
following specification:
- After 0 h, 24 h and 48 h exposure, all replicates of NC and A were sampled; one sample per replicate: 4 samples of 5 mL per treatment group.
For each sampled treatment, one of the samples from 0 h, 24 h and 48 h was sent to the analytical
laboratory at the test site menal GmbH for chemical analysis. The remaining samples were stored
as retain samples in the freezer (≤ -18 °C) until finalisation of the study.
Duplicate determination was performed. Samples were transferred into the HPLC vial and 20 µL were injected into the HPLC-UV system, where 5’-O-(4,4’-Dimethoxytrityl)thymidine was detected at 230 nm.
- Storage: All samples were stored in a freezer at - 20 °C ± 10 °C until analysis at test site menal GmbH
- Shipment: Personal handover between Hydrotox GmbH and menal GmbH

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
The stock solution was prepared as Water Soluble Fractions (WSF) by adding 50.1 mg test item to 500 mL test medium and shaking for 48 h using an overhead shaker at 23.9 – 24.8 °C in the dark. The WSF was filtered through a fibre-glass filter with a retaining range up to 0.6 µm (MN 85/70 BF, Marchery-Nagel, Düren, Germany). The filter was prepared by rinsing with purified water and preconditioning with ca. 100 mL WSF (which was discarded) to reduce adsorption of the test item. This filtered stock solution was used as single test item loading rate in the test (limit test). The negative control (NC; test medium) was treated in the same way as the test item solution.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna Straus
- Strain/clone: The test organism Daphnia magna Straus originates from the clone breeding of the Federal Environment Agency, department IV 2.4, Berlin, and has been cultivated at Hydrotox GmbH since October 2012
- Feeding during test: no

CULTURING

The daphnids are cultured at 20 ± 2 °C with 16 h light : 8 h dark and placed into fresh Elendt M4 medium twice a week. They are kept at approx. 10 animals / 200 mL and fed on workdays with Desmodesmus subspicatus algae corresponding to 0.1 mg C × daphnid-1 × day-1. The test organisms used were 1.0 - 22.5 h old at the start of the test.
Quality assurance takes place at regular intervals by testing the sensitivity of the test organisms to the reference item potassium dichromate (Sigma, Steinheim, Germany; Lot no.: MKBF2111V, expiration date: January 2018). The recent quality testing was performed in August 2017 withEC50 (24h) = 1.77 mg/L (CL 95 %: 1.63 – 2.05 mg/L), which is in the declared range of 0.6 – 2.1 mg/L (24 h) according to OECD 202.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Remarks on exposure duration:

endpoints observed after 24 and 48 hours

Hardness:

not reported

Test temperature:

20.2 - 21.0 °C

pH:

7.5 (control); 7.4 - 7.5 (test item)

Dissolved oxygen:

8.3 - 8.6 mg/L (control); 8.4 - 8.7 mg/L (test item)

Salinity:

Not applicable

Conductivity:

Not reported

Nominal and measured concentrations:

100 mg test item/L (nominal) and control
4.30 mg/L (meas., geom. mean, max. water solubility in test medium)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers 50 mL
- Type of flow-through (e.g. peristaltic or proportional diluter): static, no flow-through
- 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: Reconstituted Water (Elendt "M4"), according to OECD 202
- Culture medium different from test medium: no
- Intervals of water quality measurement: The water temperature, pH-values and dissolved oxygen concentrations were determined at test start and test end in each treatment group.

OTHER TEST CONDITIONS
- Photoperiod: 16 h light : 8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Lowest and no observed effect concentrations of test item on immobility and mortality

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
Pre-experiments were performed to determine a suitable concentration range and to establish suitable methods to prepare the test solutions. The pre-experiments were not performed in compliance with the GLP-Regulations and were excluded from the Statement of Compliance in the final report, but the raw data of these tests will be archived under the project number of the present study.
- Test concentrations: Nominal loading rates of 50, 100 and 200 mg/L test item were tested and resulted in 5, 0, and 0 % immobility after 48 hours, respectively.
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 4.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: limit of water solubility of the test item in test medium

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 4.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: limit of water solubility of the test item in test medium

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No effect on the test organisms was observable.

Reported statistics and error estimates:

No effect on the test organisms was observable, so no statistical data evaluation was performed.

- ANALYTICAL RESULTS: In the control, the test item was not detected. The measured test item concentrations in the test item treatment were 4.12 – 4.63 % of the nominal loading rate. As the measured test item concentrations are not within ± 20 % of the nominal loading rate, according to OECD 202 (2004) and OECD 23 (2000), all results are given in relation to the analytically measured test item concentrations. Therefore, the geometric mean of all three measurement times (0 h, 24 h and 48 h) was calculated. The achieved concentration is at the limit of water solubility of the test item in test medium. The test item was shaked in test medium for 48 h. Compared to the water solubility in distilled water (i.e. 3 mg/L at pH 6.8 and 20 °C, see section 4. 8 of this dossier) the solubility of the test item in Elendt M4 medium is slightly higher than in distilled water which can be explained by interactions with the salts contained in the medium.

- BIOLOGICAL RESULTS: There were no observable effects.

- VALIDITY CRITERIA:

-Immobilisation of the test organisms in the control at the end of the test was 0 % and therefore ≤ 10 %.

-Dissolved oxygen concentration in the control and the test item treatments at the end of the test was ≥ 8.3 mg/L and therefore ≥ 3 mg/L.

Therefore, the test is valid according to OECD Test Guideline 202 (13 April 2004).

Validity criteria fulfilled:

yes

Conclusions:

In an acute toxicity test according to the OECD guideline 202 Daphnia magna was exposed to 4.3 mg 4,4'-Dimethoxytrityl chloride/L (meas., geom. mean; max. water solubility). No toxic effect on D. magna was observed.

Executive summary:

The 48-hr-acute toxicity of 4,4'-Dimethoxytrityl chloride to Daphnia magna was studied under static conditions. Daphnids were exposed to control, and test chemical at measured concentration of 4.30 mg/L (geom. mean) for 48-hr in a limit test.  Mortality, immobilization and sublethal effects were observed daily. The 48-hr NOEC based on immobilization equals or is above 4.3 mg/L.

The initial concentration and the maintenance of the exposure concentrations during the test were verified in the analytical part. As the measured test item concentrations are not within ± 20 % of the nominal loading rate, according to OECD 202 (2004) and OECD 23 (2000), all results are given in relation to the analytically measured test item concentrations. The geometric mean of the measured test item concentration represents only 4.3 % of the nominal concentration which can be explained by the water solubility of the test item (i.e. 3 mg/L at pH 6.8 and 20 °C in distilled water, see section 4.8 of the present dossier). The limit of water solubility of the test item in test medium was reached. Therefore, 4,4'-Dimethoxytrityl chloride is not toxic up to the limit of water solubility to D. magna.

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

Results Synopsis

 

Test Organism Age (e.g. 1st instar): < 24 h

Test Type (Flowthrough, Static, Static Renewal): Static, Limittest

 

NOEC ≥ 4.3.mg a.i./L

LOEC > 4.3 mg a.i./L

 

Endpoint(s) Effected: mobility, mortality

Description of key information

The toxicity of 4,4'-Dimethoxytrityl chloride was assessed in a 48-hr-acute toxicity test according to OECD test guideline 202 with Daphnia magna. No effects were observed up to the limit of water solubility:

NOEC ≥ 4.30 mg a.i./L (measured)

LOEC > 4.30 a.i./L (measured)

Additional information

The 48-hr-acute toxicity of 4,4'-Dimethoxytrityl chloride to Daphnia magna was studied under static conditions. Daphnids were exposed to control, and test chemical at measured concentration of 4.30 mg/L for 48-hr in a limit test. (nominal loading rate 100 mg/L)  Mortality, immobilization and sublethal effects were observed daily. The 48-hr NOEC based on immobilization equals or is above 4.30 mg/L.

The initial concentration and the maintenance of the exposure concentrations during the test were verified in the analytical part.

The achieved concentration is at the limit of the water solubility of the test item in test medium. The test item was shaked in test medium for 48 h. Compared to the water solubility in distilled water (i.e. 3 mg/L at pH 6.8 and 20 °C, see section 4. 8 of this dossier) the solubility of the test item in Elendt M4 medium is slightly higher than in distilled water which can be explained by interactions with the salts contained in the medium.

The No Observed Effect Concentration (NOEC) is ≥ 4.30 mg/L and the Lowest Observed Effect Concentration (LOEC) is > 4.30 mg/L at 24 hours and 48 hours.

  

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.