α-chloro-2-fluorotoluene

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 12 NOV 2019 to 24 APR 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Version / remarks:

Adopted March 23, 2006, corrected July 28, 2011

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

August 24, 2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Cas Number:

345-35-7

Sampling and analysis

Analytical monitoring:

yes

Remarks:

The identity of the analyte was confirmed by comparison of the retention time with the retention time of a standard solution prepared from the test item.

Details on sampling:

- Concentrations:
100, 32, 10, 3.2 and 1.0 mg test item/L (spacing factor 3.16), corresponding to following time weighted averaged measured concentrations of the test item:
11.7, 3.63, 1.19, 0.459 and 0.149 mg test item/L, and a control.

- Sampling method:
The samples were taken from the biological phase of the study. Duplicate samples from the freshly prepared test media (containing algae) of all test concentrations and from the control were taken at the start of the test.
For the determination of the stability of the test item under the test conditions and of the maintenance of the test item concentrations during the test period, duplicate samples from the test media of all test concentrations and the control (containing algae) were taken at the end of the test (after the 72 hours test period).
Additional samples of the control and of the dilution solvent were taken at each sampling without any sample treatment.
The concentrations of the test item 2-Fluorobenzyl chloride were analysed in the duplicate test media samples from all test concentrations and in the duplicate control samples, from both sampling times (0 and 72 hours).

- Sample storage conditions before analysis:
All samples from test start were stored in a freezer (≤ - 20 °C), protected from light until analysis was performed, samples from test end were analysed directly after sampling.

Test solutions

Vehicle:

no

Details on test solutions:

A stock solution of 100 mg test item/L was prepared by dissolving 101.1 mg test item into 1011 mL test water by intense stirring for 6 hours and ultrasonic treatment for 5 minutes. Adequate volumes of this stock solution were diluted with test water to prepare the test media of the desired test concentrations.

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata,
- Strain: 61.81 SAG
- Source (laboratory, culture collection): The algae were originally supplied by the „Sammlung von Algenkulturen, Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Universität Göttingen", 37073 Göttingen, Germany. The algae were cultivated in the laboratories of ibacon under standardised conditions.
- Age of inoculum (at test initiation): The cells were taken from an exponentially growing pre-culture, which was set up 3 days prior to the test start under the same conditions as in the test.
- Method of cultivation: The algae were cultivated in the laboratory under standardised conditions according to the test guidelines.

ACCLIMATION
- Acclimation period: 3 days.
- Culturing media and conditions: same as the test.

Study design

Test type:

static

Water media type:

freshwater

Remarks:

Reconstituted Water (OECD Medium)

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

Calculated water hardness of the test water: 0.24 mmol/L (= 24 mg/L) as CaCO3.

Test temperature:

Water temperature: 21.8 to 22.8 °C

pH:

pH values in the control at test start: 8.0
pH values in the Control at test end: 9.6
pH values in the test item treatments at test start: 8.0 to 8.1,
pH values in the test item treatments at test end: 8.0 to 9.7.

Nominal and measured concentrations:

Nominal concentrations: 100, 32, 10, 3.2 and 1.0 mg test item/L
Time weighted average concentrations: 11.7, 3.63, 1.19, 0.459 and 0.149 mg test item/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Type: open
- Material, size, headspace, fill volume: 50 mL volume, covered with air permeable glass dishes, stoppers or caps
- Initial cells density: 5000 cells per mL
- Control end cells density: 242.9-fold increase within 72 hours
- No. of vessels per concentration (replicates): three replicates per concentration
- No. of vessels per control (replicates): six replicates per concentration

GROWTH MEDIUM
- Standard medium used: yes, OECD medium

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: The pH was adjusted with 1 M HCl 1 M NaOH to pH 8.1.
- Photoperiod: Continuous illumination
- Mean light intensity: 5285 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: spectrophotometric measurement

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.16
- Test concentrations: 100, 32, 10, 3.2 and 1.0 mg test item/L (nominal)

Reference substance (positive control):

yes

Remarks:

potassium dichromate (tested at least twice a year)

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

2.52 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.459 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control: yes
- Unusual cell shape: no
- Colour differences: no

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50: 72-hour EC50 = 1.34 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The influence of 2-Fluorobenzyl chloride on the growth of the freshwater green algae Pseudokirchneriella subcapitata was assessed in a static concentration-response test. The 72-hour EyC50 was calculated to be 1.57 mg test item/L, and the 72-hour ErC50 value was calculated to be 2.52 mg test item/L. The 72-hour NOEyC was determined to be 0.459 mg test item/L and the associated 72-hour LOEyC was 1.19 mg test item/L. The 72-hour NOErC was determined to be 0.459 mg test item/L and the associated 72-hour LOErC was 1.19 mg test item/L.
The initial concentrations and the maintenance of the exposure concentrations during the test were examined in the analytical part. All reported results refer to time weighted mean concentrations (TWA), since the test item concentrations were not within ± 20 % of the nominal or measured initial concentrations during the test.

Executive summary:

The purpose of this test was to determine the inhibitory effect of the test item 2-Fluorobenzyl chloride on the growth of the freshwater green algae Pseudokirchneriella subcapitata. Exponentially growing cultures of this unicellular green algal species were exposed to various concentrations of the test item under defined conditions. The inhibition of growth in relation to control cultures was determined over a test period of 72 hours. The test concentrations used were 100, 32, 10, 3.2 and 1.0 mg test item/L (spacing factor 3.16), corresponding to following time weighted averaged measured concentrations of 11.7, 3.63, 1.19, 0.459 and 0.149 mg test item/L, and a control.

The 72-hour EyC50 was calculated to be 1.57 mg test item/L, and the 72-hour ErC50 value was calculated to be 2.52 mg test item/L. The 72-hour NOEyC was determined to be 0.459 mg test item/L and the associated 72-hour LOEyC was 1.19 mg test item/L. The 72-hour NOErC was determined to be 0.459 mg test item/L and the associated 72-hour LOErC was 1.19 mg test item/L.

The initial concentrations and the maintenance of the exposure concentrations during the test were examined in the analytical part. All reported results refer to time weighted mean concentrations (TWA), since the test item concentrations were not within ± 20 % of the nominal or measured initial concentrations during the test.