2-methylbenzene-1,4-diyl bis{4-[3-(acryloyloxy)propoxy]benzoate}

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 JUN 2010 - 16 MAR 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was performed in compliance with the Good Laboratory Practice (GLP) regulations (revised in 1997, ENV/MC/CHEM(98)17). The method followed that described in the OECD Guidelines for Testing of Chemicals (Adopted: 4 April 1984) No 201 "Alga, Growth Inhibition Test", adopted March 23, 2006.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Remarks:

Please refer to 'Details on analytical methods'

Details on sampling:

Samples were taken from all flaks with algae after 24, 48 and 72 hours of exposure and were not replaced.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test medium (reconstituted water and test material) was freshly prepared. The calibrated flask with test material and vehicle, reconstituted water, was treated in an ultrasound bath for 1 hour. Subsequently, the preparation was stirred with a magnetic stirrer for further 23 hours. Afterwards, the preparation was filtered through a nutsch filter with a pore size of 10-16 µm. The filtrate was used for the study.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Green algae, Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
- Strain: SAG 86.81
- Source (laboratory, culture collection): Sammlung von Algenkulturen, Pflanzenphysiologisches Institut der Universität Göttingen
- Method of cultivation: The algae have been cultivated in the laboratories under standardized conditions. Prior to start the study, the algae were grown in reconstituted water as preculture and the growth rate was determined.

ACCLIMATION
- Acclimation period: 3 days
- Culturing media and conditions (same as test or not): same as test
The experimental part was started by inoculation of algae to the different groups so that the flasks contained about 10,000 cells/mL. The algae were taken from an exponentially growing pre-culture (growth rate 120.7) which was set up 3 days prior to the experimental part under the same conditions as in the final study.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Hardness:

250 mg CaCO3

Test temperature:

22 °C

pH:

8.0±0.3

Dissolved oxygen:

about 80 %

Salinity:

for details see composition of reconstituted water "details on test conditions"

Nominal and measured concentrations:

The study was performed with nominal concentrations of 0 and 100 mg/L in reconstituted water.

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 30 mL, covered with cellulose stoppers
- Aeration: continuously shaken
- Initial cells density: 10,000 algae cells/mL
- Control end cells density: mean: 289,240 cells/mL
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 3
- No. of vessels per vehicle control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The test medium (reconstituted water and test material) was freshly prepared.

Details on composition of the reconstituted water:

Macro-nutrients:
50.00 mg/L NaHCO3
18.00 mg/L CaCl2 x 2 H2O
15.00 mg/L NH4Cl
15.00 mg/L MgSO4 x 7 H2O
12.00 mg/L MgCl2 x 6 H2O
1.60 mg/L KH2PO4

Trace elements:
100.00 µg/L Na2EDTA x 2 H2O
64.00 µg/L FeCl3 x 6 H2O
415.00 µg/L MnCl2 x 4 H2O
185.00 µg/L H3BO3
7.00 µg/L Na2MoO4 x 2 H2O
3.00 µg/L ZnCl2
1.50 µg/L CoCl2 x 6 H2O
0.01 µg/L CuCl2 x 2 H2O

The pH of the reconstituted water after aeration is approximately 8.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: continuously
- Light intensity and quality: 7500 to 9500 Lux. The illumination was achieved by fluorescent tubes (Philips Master TL5 - 80 W/840 HO) installed above a rotating panel with the flasks.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: electronic particle counter (observation interval 24 h)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: none
- Justification for using less concentrations than requested by guideline: limit test due to low water solubility
- Range finding study: not required
- Test concentrations: 0, 100 mg/L (nominal)

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): yes
- Any stimulation of growth found in any treatment: yes, the mean growth rates found in the treatments after 24, 48 and 72 h were higher than the mean growth rates in the vehicle control.

Results with reference substance (positive control):

Regularly, a positive control test to check the test system is carried out with potassium dichromate
- Results with reference substance valid? yes, the EC values lie within the recommended range (growth rate EC50 = 0.60 - 1.03 mg/L)
- EC50: 0.85 mg/L based on growth rate

Reported statistics and error estimates:

NA

Validity of the test

In the control group the biomass increased by a factor of 29.9 over 72 hours. The validity criterion of increase of biomass by at least a factor of 16 within three days was fulfilled. The mean coefficient of variation of the daily growth rates in the control group (section-by-section growth rates) during 72 hours was 21.5%. According to the OECD test guideline, the mean coefficient of variation must not be higher than 35%. Thus, the validity criterion was fulfilled. The coefficient of variation of the average specific growth rates in the replicates of the control group after 72 hours was 1.3 %. According to the OECD test guideline, the coefficient of variation must not be higher than 7%. Thus, the validity criterion was fulfilled.

Validity criteria fulfilled:

yes

Remarks:

Please refer to 'Any other information on results'

Conclusions:

An aqueous preparation of 100 mg/L (nominal) of the test substance revealed no toxic effect in the test system. The 72 hours EC50 could not be determined, because it exceeded the maximum solubility of the test material in reconstituted water (EC50 > 0.04 mg/L).

Executive summary:

The registered substance was tested for toxicity to algae in an acute growth inhibition test according to OECD Guideline 201 following GLP.

Purpose
The purpose of this assay was to identify the aquatic toxicity potential in algae to provide a rational basis for hazard estimation for the test item in aquatic environments.

Study Design
The study design included one control group and one test material group with six replicates, each containing 100 mL reconstituted water or test medium and about 10,000 cells/mL at the start of the experimental phase. The study was performed as a limit test in an open static test system. The algae were exposed to a filtrate of nominal 100 mg/L. The growth of the algae was calculated after 24, 48, and 72 hours exposure in the test medium.

Results

The test material concentration in the reconstituted water was not quantified at the start and the end of this study due to the low water solubility (< 0.04 mg/L). Because of the low water solubility, the compound cannot be detected with standard analytical methods. The development of an analytical method with a sufficiently low detection and quantification limit is complex. Due to the absence of any adverse effects at the saturation concentration, the study was performed without analytical concentration verification.

For the test material the following EC values, low effect and no effect concentration for Desmodesmus subspicatus were determined:

Parameter (0-72h)	Growth rate	Yield
EC10 (mg/L) 95% confidence interval	>0.04 (nominal >100 mg/L) n.d.	>0.04 (nominal >100 mg/L) n.d.
EC20 (mg/L) 95% confidence interval	>0.04 (nominal >100 mg/L) n.d.	>0.04 (nominal >100 mg/L) n.d.
EC50 (mg/L) 95% confidence interval	>0.04 (nominal >100 mg/L) n.d.	>0.04 (nominal >100 mg/L) n.d.
NOEC (mg/L)	≥0.04 (nominal >100 mg/L)	≥0.04 (nominal >100 mg/L)
LOEC (mg/L)	>0.04 (nominal >100 mg/L)	>0.04 (nominal >100 mg/L)

n.d.   could not be determined

Conclusion
An aqueous preparation of 100 mg/L (nominal) of the test substance revealed no toxic effect in the test system. The 72 hours EC50 could not be determined, because it exceeded the maximum solubility of the test material in reconstituted water (EC50 > 0.04 mg/L).

Description of key information

Key, growth inhibition, D. subspicatus, limit test, OECD 201, GLP: EC50 > 100 mg/L (nominal), EC10 and NOEC > 100 mg/L (nominal) after 72 h.

Additional information

Growth rate inhibition, OECD 201

The registered substance was tested for toxicity to algae in an acute growth inhibition test according to OECD Guideline 201 following GLP.

Purpose
The purpose of this assay was to identify the aquatic toxicity potential in algae to provide a rational basis for hazard estimation for the test item in aquatic environments.

Study Design
The study design included one control group and one test material group with six replicates, each containing 100 mL reconstituted water or test medium and about 10,000 cells/mL at the start of the experimental phase. The study was performed as a limit test in an open static test system. The algae were exposed to a filtrate of nominal 100 mg/L. The growth of the algae was calculated after 24, 48, and 72 hours exposure in the test medium.

Results

The test material concentration in the reconstituted water was not quantified at the start and the end of this study due to the low water solubility (< 0.04 mg/L). Because of the low water solubility, the compound cannot be detected with standard analytical methods. The development of an analytical method with a sufficiently low detection and quantification limit is complex. Due to the absence of any adverse effects at the saturation concentration, the study was performed without analytical concentration verification.

For the test material the following EC values, low effect and no effect concentration for Desmodesmus subspicatus were determined:

Parameter (0-72h)	Growth rate	Yield
EC10 (mg/L) 95% confidence interval	>0.04 (nominal >100 mg/L) n.d.	>0.04 (nominal >100 mg/L) n.d.
EC20 (mg/L) 95% confidence interval	>0.04 (nominal >100 mg/L) n.d.	>0.04 (nominal >100 mg/L) n.d.
EC50 (mg/L) 95% confidence interval	>0.04 (nominal >100 mg/L) n.d.	>0.04 (nominal >100 mg/L) n.d.
NOEC (mg/L)	≥0.04 (nominal >100 mg/L)	≥0.04 (nominal >100 mg/L)
LOEC (mg/L)	>0.04 (nominal >100 mg/L)	>0.04 (nominal >100 mg/L)

n.d.   could not be determined

Conclusion
An aqueous preparation of 100 mg/L (nominal) of the test substance revealed no toxic effect in the test system. The 72 hours EC50 could not be determined, because it exceeded the maximum solubility of the test material in reconstituted water (EC50 > 0.04 mg/L).