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Ecotoxicological information

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:
02.03.2010 to 09.07.2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
impurity
Test material form:
solid
Specific details on test material used for the study:
4-(Methacryloyloxy) bezophenone 97.26 %
Benzophenone acetate: 1.95 %

Sampling and analysis

Analytical monitoring:
no
Details on sampling:
One sample from the freshly prepared stock solution and 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

Analysis:
The concentrations of the test item were analysed in the duplicate test media samples from the three highest test concentrations and both sampling times (0 and 72 hours). From the control samples only one of the duplicate samples was analysed from each of both sampling
times. All samples were centrifuged before analysis, in order to remove the algae.
end of the test ( after the 72 hours test period).
All samples were diluted with methanol by a factor of 2 directly after sampling.

Storage of Samples: All samples were measured directly after sampling.
Fortified Samples: 50 mg of the test item were dissolved in 50 mL methanol to obtain a stock solution of 1 g test item/L. Appropriate amounts of this stock solution were diluted with test water to obtain fortified samples at a Ievel of 0.075, 0.2 and 1 mg test item/L.

Test solutions

Vehicle:
no
Details on test solutions:
A water accommodated fraction of 10 mg/L and subsequent dilutions, resulting in nominal concentrations of 1.0, 0.32, 0.10, 0.032 and 0.010 mg test item/L. Additionally, a control was tested in parallel.
The two highest test concentrations of nominal 1.0 and 0.32 mg test item/L correspond to the arithmetic mean measured concentrations of 0.21 and 0.06 mg test item/L.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Pseudokirchneriella subcapitata, Strain No. 61.81 SAG

Study design

Test type:
static
Water media type:
freshwater
Total exposure duration:
72 h

Test conditions

Hardness:
Calculated water hardness of the test water: 0.24 mmol/L (= 24 mg/L) as CaC03.
Test temperature:
23 °C
pH:
8.1 at test start and 8.8-9.0 at test end
Nominal and measured concentrations:
A water accommodated fraction of 10 mg/L and subsequent dilutions, resulting in nominal concentrations of 1.0, 0.32, 0.10, 0.032 and 0.010 mg test item/L. Additionally, a control was tested in parallel.
The two highest test concentrations of nominal 1.0 and 0.32 mg test item/L conespond to the arithmetic mean measured concentrations of 0.21 and 0.06 mg test item/L.
Details on test conditions:
25 hours before test start a suspension of a nominal concentration of 10 mg!L was prepared by suspending 10 mg test item into 1000 mL test water. The suspension was stirred for 22 hours in the dark to dissolve as much test item as possible. After a 3 hour cessation period
the dissolved fractions of the test item were taken from the middle of the test vessel. Adequate volumes of this water accommodated fractions were mixed into test water to prepare nominal test
concentrations of 1.0, 0.32, 0.10, 0.032 and 0.010 mg test item/L.
The test media were prepared just before introduction of the algae (= start of the test).

Introduction of Algae:
The test was started (0 hours) by inoculation of a biomass of 5000 algal cells per mL test medium. These cells were taken from an exponentially grnwing pre-culture, which was set up 4 days prior to the test start under the same conditions as in the test.

Replicates:
The test was performed with three replicates per test concentration and six replicates in the control. Volumes of 50 mL of algal suspension per replicate were continuously stirred with magnetic stirrers in 50 mL Erlemneyer flasks. The flasks were covered with
glass dishes and incubated in a water bath.

Blanks:
Additionally, one replicate of each test concentration and of the control was prepared without algae to provide a "blank" for the spectrophotometrical measurements.

Exposure time: 72 h
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 0.21 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other:
Remarks:
95 % conf. limits: n.d.
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
>= 0.21 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 95 % conf. limits: n.d.
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
> 0.21 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
> 0.21 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 0.21 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
>= 0.21 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
> 0.21 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
> 0.21 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Reported statistics and error estimates:
The software used to perform the statistical analysis was ToxRat Professional, Version 2.10, ToxRat® Solutions GmbH, 2009.

Any other information on results incl. tables

Determination of the Test Item: Based on the results of HPLC measurements the concentration of the test item was determined using a calibration curve.

Calibration Range: 0.025 to 0.5 mg test item/L

Linearity of Response: Correlation of peak area of different standard solutions with their corresponding concentrations, using a linear regression

Regression Coefficient: At least 0.9950

Typical Calibration Curve: y = 917153 * x - 7280

Limit of Detection: 0.00075 mg test item/L

Limit of Quantification: 0.0075 mg test item/L

Mean Recovery in the Fortified Samples: 107% (n = 12, RSD 13 %)

Summary of Analytical Results

nominal

concentration

[mg/L]

neasured

concentration

[mg/L]1

n

control

n.a.

2

0.10

n.a.

4

0.32

0.056

4

1.0

0.212

4

 

 

 

1arithmetic mean value of all measured samples per treatment group

RSD relative standard deviation per treatrnent group

n.a. not applicable

n number of analysed samples

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The influence of 4-(Methacryloyloxy)benzophenone on the growth of the freshwater green algae Pseudokirchneriella subcapitata was assessed in a static dose-response test. The 72-hour NOEC was determined to be at least the limit of water solubility, corresponding to an arithmetic mean measured test concentration of 0.21 mg test item/L. The NOEC might even be higher than this concentration, but concentrations in excess of the limit of solubility have not been tested according to the recommendations of the test guidelines.
The 72-hour LOEC and the 72-hour EC50 were clearly higher than the limit of water solubility, corresponding to an arithmetic mean measured test concentration of 0.21 mg test item/L.
Executive summary:

The influence of 4-(Methacryloyloxy)benzophenone on the growth of the freshwater green algae Pseudokirchneriella subcapitata was assessed in a static dose-response test (OECD Guideline 201 (Alga, Growth Inhibition Test). The 72-hour NOEC was determined to be at least the limit of water solubility, corresponding to an arithmetic mean measured test concentration of 0.21 mg test item/L. The NOEC might even be higher than this concentration, but concentrations in excess of the limit of solubility have not been tested according to the recommendations of the test guidelines. The 72-hour LOEC and the 72-hour EC50 were clearly higher than the limit of water solubility, corresponding to an arithmetic mean measured test concentration of 0.21 mg test item/L.