Benzyl methacrylate

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:

2012-01-24 to 2012-02-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

adopted 23 March 2006

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Name of test material (as cited in study report): Benzyl methacrylate

Analytical monitoring:

yes

Details on sampling:

The concentrations of the test item were analytically determined from all test concentrations and the control after 0 hours (test start) and 72 hours (test end). Samples at test start were taken from an additional replicate without algae. At end of the test samples were taken directly from the pooled test replicates.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
stock solution: 10.0 mg/L, freshly prepared with dilution water
The stock solution was treated with ultrasound for 15 min and stirred with approximately 500 rpm for 1 h at room temperature.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Strain: Desmodesmus subspicatus CHODAT SAG 86.81
- Source (laboratory, culture collection): Sammlung von Algenkulturen (SAG), Pflanzenphysiologisches Institut der Universität Göttingen, Nikolausberger Weg 18, 37073 Göttingen, Germany
- Age of inoculum (at test initiation): four day old preculture, prepared in dilution water, was used as inoculum


ACCLIMATION
- Acclimation period: no data
- Culturing media and conditions (same as test or not): according to the guideline (OECD 201 medium)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

21.5-23°C

pH:

initial: 7.71 - 7.95
final: 7.80 - 8.70

Nominal and measured concentrations:

nominal: 0.625, 1.25, 2.50, 5.00, 10.0 mg/L
measured (geometric mean): 0.436, 0.899, 1.84, 4.11, 7.67 mg/L, corresponding to 80 to 106% of the nominal values

Details on test conditions:

TEST SYSTEM
- Test vessel: Sterile Erlenmeyer flasks, capacity: 250 mL, sealed with cotton wool plugs, fill volume 100 mL
- Aeration: agitation, Test containers were placed on a rotary shaker and oscillated at approximately 70 rpm
- Initial cells density: 4910 cells/mL
- Control end cells density: mean 688203 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes, OECD 201 medium

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Photoperiod: 24 hours/day light
- Light intensity and quality: mean 67.0 µE/m²/s (CV 6.14%)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
Cell density was measured daily via Chlorophyll-a- fluorescence,excitation at 436 nm, emission at 685 nm

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study
- Test concentrations: 0.01, 0.10, 1.00, 10.00, 100.00 mg/L
- Results used to determine the conditions for the definitive study:
Growth inhibition 100% at 100.00 mg/L , 100% at 10.00 mg/L, -1% at 1.00 mg/L, 2% at 0.10 mg/L, 3% at 0.01 mg/L
Yield inhibition 100% at 100.00 mg/L, 100% at 10.00 mg/L, -4% at 1.00 mg/L, 11% at 0.10 mg/L; -13% at 0.01 mg/L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.899 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

1.08 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CL 0.963 – 1.21 mg/L

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

2.28 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CL: 2.13 – 2.45 mg/L

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.899 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.969 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% CL 0.836 – 1.15 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

1.31 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% CL: 1.13 – 1.53 mg/L

Results with reference substance (positive control):

- Results with reference substance valid?
- ErC50: 0.488, 95 % confidence interval: 0.466 – 0.512 / valid range: 0.699 ± 0.471
- EyC50: 0.291, 95 % confidence interval: 0.274 – 0.328 / valid range: 0.318 ± 0.147

Reported statistics and error estimates:

EC50-values of the growth rate and yield inhibition after 72 hours were calculated by sigmoidal dose-response regression. Calculation of the confidence intervals EC50-values were carried out using standard procedures.

Mean cell densities [cells/mL] during the final test:

Geometric mean measured test item concentration[mg/L]	Exposure time [h]
	0	24	48	72
7.67	4910	4467	3110	3207
4.11	4910	7237	5227	12771
1.84	4910	19436	26642	99821
0.899	4910	20841	111334	666945
0.436	4910	18290	121430	792608
Control	4910	16877	106589	688203

  

Growth rate, yield during the final test: 

Geometric mean measured test item concentration [mg/L]	Growth rate [/d]	Rate-related inhibition [%]	Yield [cells/mL]	Inhibition of yield [%]
7.67	-0.142	100	0	100
4.11	0.318	80.6	7861	98.9
1.84	1.00	38.9	94911	86.1
0.899	1.64	0.47	662035	3.11
0.436	1.69	-2.80	787698	-15.3
control	1.64		683293

 

Validity criteria fulfilled:

yes

Conclusions:

In this study BNMA was found to inhibit the growth of the freshwater green alga Desmodesmus subspicatus after 72 hours.
The NOEC, EC10 and EC50 values based on growth rate were 0.899 mg/L, 1.08 mg/L (95% CL 0.963 – 1.21 mg/L) and 2.28 mg/L, respectively.  The % growth inhibition in the treated algal culture as compared to the control ranged from -2.80 to 100.
The NOEC, EC10 and EC50 values based on yield were 0.899 mg/L, 0.969 mg/L (95% CL 0.836 – 1.15 mg/L) and 1.31 mg/L, respectively
All effect levels are given based on geometric mean measured concentrations of BNMA.

Executive summary:

In a 72 hour acute toxicity study, the cultures of Desmodesmus subspicatus CHODAT SAG 86.81 were exposed to BNMA at measured concentrations of 0 (control), 0.436, 0.899, 1.84, 4.11 and 7.67 mg/L under static conditions in accordance with the OECD guideline 201 (adopted 23 March 2006). 

The NOEC, EC10 and EC50 values based on growth rate were 0.899 mg/L, 1.08 mg/L (95% CL 0.963 – 1.21 mg/L) and 2.28 mg/L, respectively.  The % growth inhibition in the treated algal culture as compared to the control ranged from -2.80 to 100.

The NOEC, EC10 and EC50 values based on yield were 0.899 mg/L, 0.969 mg/L (95% CL 0.836 – 1.15 mg/L) and 1.31 mg/L, respectively

 

Microscopic evaluation of the cells at start and end of the incubation period revealed no morphological abnormalities.

 

Results Synopsis

 

Test Organism: Desmodesmus subspicatus CHODAT SAG 86.81

Test Type: Static

 

72 hr ErC50: 2.28 mg/L              95% C.I.: 2.13 – 2.45 mg/L

72 hr EyC50: 1.31 mg/L             95% C.I.: 1.13 – 1.53 mg/L

72 hr ErC10: 1.08 mg/L              95% C.I.:  0.963 – 1.21mg/L

72 hr EyC10: 0.969 mg/L             95% C.I.:  0.836 – 1.15 mg/L

72 hr NOEC: 0.899mg/L              

Endpoint(s) Effected:  growth rate, yield

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Description of key information

The 72 h EC10 for BNMA in freshwater algae was 1.08 mg/L. The 72 h EC50 for BNMA in freshwater algae was 2.28 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

2.28 mg/L

EC10 or NOEC for freshwater algae:

1.08 mg/L

Additional information

One study in freshwater algae is available for BNMA, which is considered reliable without restriction (Klimisch score 1).

 

In a 72 hour toxicity study, the cultures of Desmodesmus subspicatus CHODAT SAG 86.81 were exposed to BNMA at measured concentrations of 0 (control), 0.436, 0.899, 1.84, 4.11 and 7.67 mg/L under static conditions in accordance with the OECD guideline 201 (adopted 23 March 2006).

The % growth inhibition in the treated algal culture as compared to the control ranged from -2.80 to 100. Microscopic evaluation of the cells at start and end of the incubation period revealed no morphological abnormalities.The NOEC, EC10 and EC50 values based on growth rate were 0.899 mg/L,1.08 mg/L and 2.28 mg/L, respectively.