Registration Dossier

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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Well documented study according to international accepted guideline and GLP compliant.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2015
Report Date:
2015

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
Test item: 4-nitrophenyl-acetic acid
CAS number: 104-03-0
EC number: 203-168-5
Molecular formula: C8H7NO4
Molecular weight: 181.15 g/mol
Physical state: Solid, crystalline powder
Colour: Yellowish
Storage: Cool, dry place, protected from light

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
yes

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Test species: Pseudokirchneriella subcapitata (Korshikov) F.Hindák (formerly known as Selenastrum capricornutum)
Source: UTEX The Culture Collcetion of Algae (USA).
The test organism was grown and hold in OECD medium which was used also for preparing of saturated test item solution.

Study design

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

Test conditions

Test temperature:
The temperature inside the incubator at the test vessels was measured and registered continuously by thermometer and datalogger. Throughout the test the temperature was nearly constant.
pH:
The measured mean pH values at the beginning of the test varied in the range of 6.32 - 7.63.
The measured mean pH values at the end of the test varied in the range of 7.87 - 9.44.
Nominal and measured concentrations:
In the test the following nominal concentrations were applied: 60.04; 30.02; 15.01; 10.01; 5.00; 3.00; and 1.50 mg/L.
the geometric mean value of measured
and calculated concentrations of 1.33; 0.92; 0.64; 0.51; 0.35; 0.27 and 0.20 mg test
item/L.
Details on test conditions:
The toxic property of test item was investigated at seven concentrations which were prepared by different dilutions of stock solution of test item. At each concentration level three replicates were used. In the case of control six replicates were applied. The initial alga concentration was 5 000 cells/ml. The vessels were closed with silicone bungs with a filter for ensuring the proper air exchange. The vessels were kept in incubator at 21 ± 2 °C with continuous illumination.

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
0.24 mg/L
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
0.26 mg/L
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
0.32 mg/L
Conc. based on:
test mat.
Basis for effect:
growth rate
Details on results:
The ECx for specific growth rate and yield were determined by ToxRat® statistic software.
The values of LOEC and NOEC were also calculated by ToxRat® statistic software but the results were not conclusive or determinable.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
According to this Freshwater Alga and Cyanobacteria, Growth Inhibition Test for 4-nitrophenyl-acetic acid (CAS No. 104-03-0) the results indicated that the test item is hazardous to the aquatic environment and classified into the first acute toxic hazardous category [GHS Acute aquatic hazard Category Acute I. – 72 hr EC50 (for algae or other aquatic plants) ≤ 1 mg/L].