(S)-α-hydroxy-3-phenoxy-benzeneacetonitrile

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

441-070-6

EC Name:

-

Cas Number:

61826-76-4

Molecular formula:

C14H11NO2

IUPAC Name:

(2S)-2-hydroxy-2-(3-phenoxyphenyl)acetonitrile

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Because of the very fast and complete hydrolysis of the test substance, the initial concentration of the test substance cannot be determined. Therefore the actual concentrations of the hydrolysis product were determined by HPLC in filtered samples of the cultures exposed to the test substance and also in one blank with the highest concentration of the test substance, but no algae, at the start of the experiment and after 72 hours of incubation

Test solutions

Details on test solutions:

Identity and concentration of auxiliary solvent for dispersal: Water was used.

Test organisms

Test organisms (species):

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

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.34 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.47 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.13 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.13 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Any other information on results incl. tables

Actual concentrations:
The test substance was completely hydrolysed already at the start of the incubation. The actual concentrations of the hydrolysis product were corresponding to between 100.8 % and 107.7 % of the nominal concentrations of the test substance. After 72 hours of incubation the actual hydrolysis product
concentrations were in the test cultures between 89.5 % and 100.0 % of the actual starting concentrations. In the blank without algae the actual hydrolysis product concentration was 102.2 % of the actual starting concentration. These
results give no indication for an uptake of the test substance / hydrolysis product by the algae or for adherence of the test substance to them.

pH:

The test substance did not alter the pH of the test media. After 72 hours of incubation there was also no obvious difference in the pH values of the control and test cultures.

Increase in cell densities:

During the 72 hours incubation period the cell density in the control cultures was increased by a factor of about 54 (about 5.8 concentrations)

Growth inhibition:

Algal growth was inhibited by about 97% (based on the area under the growth) or by about 90% (based on the average growth rates) at the nominal test substance concentration of 3.00 mg/L. The lowest tested concentration (0.13 mg per L medium, nominal) only slightly inhibited algal growth by about 13 or 3% compared to the negative controls.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 72-hour EC50 (growth rate) for Selenastrum capricornutum towards the test item was determined with 0.47 mg/L.

Executive summary:

The 72-hour EC50 (growth rate) for Selenastrum capricornutum towards the test item was determined with 0.47 mg/L.