Benzyl phenylacetate

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Data is from ABITEC study report.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Principles of method if other than guideline:

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance Benzyl phenylacetate (CAS no. 102-16-9) according to OECD Guideline 201.

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): Benzyl phenylacetate
- Molecular formula (if other than submission substance): C15H14O2
- Molecular weight (if other than submission substance): 226.2736 g/mol
- Smiles notation (if other than submission substance):c1(CC(OCc2ccccc2)=O)ccccc1
- InChI:1S/C15H14O2/c16-15(11-13-7-3-1-4-8-13)17-12-14-9-5-2-6-10-14/h1-10H,11-12H2
- Substance type: Organic
- Physical state: Liquid

Analytical monitoring:

not specified

Vehicle:

yes

Details on test solutions:

The stock solution (100 mg/L) was prepared by dissolving colourless liquid in acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Remarks on exposure duration:

±1 hour

Test temperature:

23±2°C

pH:

The sample at test concentration 100 mg/l : pH = 8.1 changed to pH = 7.7 during the test.
Control: 8.3 (changed to 7.9 during test)
control + acetone: pH = 8.3 changed to pH = 7.9 during the test

Nominal and measured concentrations:

0, 6.25, 12.5, 25, 50 and 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml Glass vessel
- Type (delete if not applicable): closed (with air permeable stopper)
- Sample volume: 15 ml
- Initial cells density: 5x10(3) cells/ml
- No. of vessels per concentration (replicates): 3
- Other:
Control solution: OECD growth medium without the sample, the coefficient of variation of average growth rate in replicates during the whole test period was 1.1% in control and 1.0% in control + acetone.

GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: Continuous
- Light intensity and quality: 6000-8000 lx

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: microscope with counting chamber Cyrus I or electronic particle counter.
- Other: ErC50 was calculated using non-linear regression by the software Prism 4.0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7) was used as a reference substance for the study.

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

34.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CL: 29.4 - 40.4

Results with reference substance (positive control):

Results with reference substance valid
- EC50: 0.69 mg/L

Validity criteria fulfilled:

not specified

Conclusions:

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance Benzyl phenylacetate to OECD Guideline 201. The median effective concentration (EC50) for the test substance Benzyl phenylacetate in Desmodesmus subspicatus was determined to be 34.5 mg/L on the basis of effects on growth rate in a 72 hour study.

Executive summary:

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance Benzyl phenylacetate (CAS no. 102 -16 -9) to OECD Guideline 201. The stock solution (100 mg/L) was prepared by dissolving colourless liquid in acetone. Test solutions  of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Conc. of test chemical used for the study was 0, 6.25, 12.5, 25, 50 and 100 mg/L, respectively. The test was performed under static conditions in a static fresh water system at a temp. of 23±2°C. Initial cell density of test organism used was 5x10(3) cells/ml. Determination of cell counting involve the use of microscope with counting chamber Cyrus I or electronic particle counter. ErC50 was calculated using non-linear regression by the software Prism 4.0. The median effective concentration (EC50) for the test substance Benzyl phenylacetate in Desmodesmus subspicatus was determined to be 34.5 mg/L on the basis of effects on growth rate in a 72 hour study. Thus, based on this value, test chemical Benzyl phenylacetate can be considered as toxic to aquatic organisms and thus can be classified as aquatic chronic category 3 as per the CLP criteria.

Description of key information

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance Benzyl phenylacetate (CAS no. 102 -16 -9) to OECD Guideline 201 (ABITEC study report, Sustainability Support Services (Europe) AB, 2017). The stock solution (100 mg/L) was prepared by dissolving colourless liquid in acetone. Test solutions  of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Conc. of test chemical used for the study was 0, 6.25, 12.5, 25, 50 and 100 mg/L, respectively. The test was performed under static conditions in a static fresh water system at a temp. of 23±2°C. Initial cell density of test organism used was 5x10(3) cells/ml. Determination of cell counting involve the use of microscope with counting chamber Cyrus I or electronic particle counter. ErC50 was calculated using non-linear regression by the software Prism 4.0. The median effective concentration (EC50) for the test substance Benzyl phenylacetate in Desmodesmus subspicatus was determined to be 34.5 mg/L on the basis of effects on growth rate in a 72 hour study. Thus, based on this value, test chemical Benzyl phenylacetate can be considered as toxic to aquatic organisms and thus can be classified as aquatic chronic category 3 as per the CLP criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:

34.5 mg/L

Additional information

Experimental key studyfor the target chemicalBenzyl phenylacetate(CAS no. 102-16-9) which is supported further by experimental study for its closest structurally similar read across substance with logKow as the primary descriptor were reviewed for the toxicity to aquatic algae and cyanobacteria end point which are summarized as below:

 

In an experimental key study,freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the test substance Benzyl phenylacetate (CAS no. 102 -16 -9) according to OECD Guideline 201(Alga, Growth Inhibition Test) (ABITEC study report, Sustainability Support Services (Europe) AB, 2017). The stock solution (100 mg/L) was prepared by dissolving colourless liquid in acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Conc. of test chemical used for the study was 0, 6.25, 12.5, 25, 50 and 100 mg/L, respectively. The test was performed under static conditions in a static fresh water system at a temp. of 23±2°C. Initial cell density of test organism used was 5x10(3) cells/ml. Determination of cell counting involve the use of microscope with counting chamber Cyrus I or electronic particle counter. ErC50 was calculated using non-linear regression by the software Prism 4.0. The median effective concentration (EC50) for the test substance Benzyl phenylacetate in Desmodesmus subspicatus was determined to be 34.5 mg/L on the basis of effects on growth rate in a 72 hour study. Thus, based on this value, test chemical Benzyl phenylacetate can be considered as toxic to aquatic organisms and thus can be classified as aquatic chronic category 3 as per the CLP criteria.

 

In a supporting study of read across substance 2-Phenethyl phenylacetate (CAS no. 102-20-5), the effect of read across substance 2-Phenethyl phenylacetate, CAS No. 102-20-5 was studied on the growth of fresh water green alga Chlorella vulgaris (UERL Study report, Sustainability Support Services (Europe) AB, 2015). The study was conducted following OECD guideline 201- Alga growth inhibition test. The test concentration chosen for the study were 2 mg/l, 3 mg/l, 4.5 mg/l, 6.75 mg/l, 10.13 mg/l and 15.19 mg/l were prepared using stock solution of the test substance using de-ionized water. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of test substance. EC50 calculated graphically through probit analysis was observed to be 13.89 mg/l. Thus, based on this value, test chemical 2-Phenethyl phenylacetate can be considered as toxic to aquatic organisms and thus can be classified as aquatic chronic category 3 as per the CLP criteria.

 

Thus, based on the overall reported results for target chemicalBenzyl phenylacetate (ABITEC study report, 2017) and for its read across substance (UERL study report, 2015), it can be concluded that the test substanceBenzyl phenylacetatecan be considered astoxic to aquatic organisms at environmentally relevant concentrations and can be considered to be classified inaquatic chronic category 3as per the CLP classification criteria.