Phenylacetic acid

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:

2 (reliable with restrictions)

Qualifier:

according to guideline

Guideline:

other:

Principles of method if other than guideline:

Data is from publication

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

not specified

Details on test solutions:

The carrier of fluoranthene and its metabolites was a recommended mineral medium, composed for the test as follows (mg/l):
NH4Cl ¼ 15; MgCl2 6H2O ¼ 12; CaCl2 2H2O ¼ 18; MgSO4 7H2O ¼ 15; KH2PO4 ¼ 1.6; NaHCO3 ¼ 50 and (lg/l): FeCl3 6H2O ¼ 80; Na2EDTA 2H2O ¼ 100;
H3BO3 ¼ 185; MnCl2 4H2O ¼ 415; ZnCl2 ¼ 3; CoCl2
6H2O ¼ 1.5; CuCl2 2H2O ¼ 0.01 and Na2MoO4
2H2O ¼ 7. The pH was adjusted to 8.30.2.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Source: National Institute of Biology (NIB, Ljubljana, Slovenia).

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

7 d

Details on test conditions:

Method: In mineral medium; algal culture incubated with geometric dilution of 10 concentrations of title comp. for 7 days; at day 0 and after 7 days algal cells counted, growth rate with interpolation used.
Further Details : 12 h day/night photoperiod with blue and red wavelengths; for each concentration four replicate samples and one blank sample prepared

Reference substance (positive control):

not specified

Duration:

7 d

Dose descriptor:

EC50

Effect conc.:

177 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: growth inhibition

Conclusions:

The effective concentration (EC50) value of test material in aquatic green algae [Scenedesmus subspicatus] on the basis of growth inhibition effect was found to be 177mg/L.Thus,considering the CLP Criteria for aquatic classification of the substance , it isconcluded that test material does not exhibit toxicity to aquatic green algae [Scenedesmus subspicatus].

Executive summary:

The effective concentration (EC50) value of test material in aquatic green algae [Scenedesmus subspicatus] on the basis of growth inhibition effect was found to be 177 mg/L.Thus,considering the CLP Criteria for aquatic classification of the substance , it isconcluded that test material does not exhibit toxicity to aquatic green algae [Scenedesmus subspicatus].

Description of key information

Toxicity to aquatic algae and cyanobacteria:

The effective concentration (EC50) value of test material in aquatic green algae [Scenedesmus subspicatus] on the basis of growth inhibition effect was found to be 177 mg/L.Thus,considering the CLP Criteria for aquatic classification of the substance , it isconcluded that test material does not exhibit toxicity to aquatic green algae [Scenedesmus subspicatus].

Key value for chemical safety assessment

EC50 for freshwater algae:

177 mg/L

Additional information

Toxicity to aquatic algae and cyanobacteria:

The effect of test material on aquatic algae was described in a peer reviewed journal , the effective concentration (EC50) value of test material in aquatic green algae [Scenedesmus subspicatus] on the basis of growth inhibition effect was found to be 177 mg/L.Thus,considering the CLP Criteria for aquatic classification of the substance , it isconcluded that test material does not exhibit toxicity to aquatic green algae [Scenedesmus subspicatus].

The above data was further supported by data for structurally similar read across substance , the effect of test substance was studied on the growth of fresh water green algaChlorella vulgaris.The study was conducted following OECD guideline 201- Alga growth inhibition test.The test substance , was prepared by adding 106.25 mg of test substance in 250 ml of BBM to get the final concentration of 425 mg/L. The sock solution was ultrasonically agitated for 30 minutes to obtain a homogenous solution for the experiment. The remaining test solutions were prepared by dilution from the above stock solution, under aseptic condition. To have a better growth and visibility of cells, the initial cell density of the culture was kept 1 X 104 cells/ml. Care was taken to have a homogeneous solution for the experiment.

The test concentration chosen for the study were 4.32mg/l, 10.88 mg/l, 27.2mg/l, 68mg/l, 170mg/l and 425mg/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 from equation through probit analysis was observed to be 138.96 mg/L.