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
Study period:
14 August 2015-26 August 2015
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2015
Report Date:
2016

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: solid
Details on test material:
Lot no. 280001T01O
Purity 100% (m/m)
Molecular formula C8H5ClFN
Molecular mass 169.6 g/mol
Water solubility 432.2 mg/l at pH 6.7 and 20 °C, as determined in an OECD 105 test (ACH study no. A15-01315)
Test item storage At room temperature, protected from light
Stability Stable under storage conditions
Expiry date 31 December 2015

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
yes

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Study design

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

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 12.3 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Executive summary:

The effective concentrations (ErC10, ErC20, ErC50 and EyC10, EyC20, EyC50) as well as the no observed effect concentrations (NOErC and NOEyC), of PAC-Nitrile (CAS No. 75279-53-7) to the green alga Desmodesmus subspicatus, were investigated over a period of 72 h, based on the average specific growth rate and the yield (algal biomass production).

The test item PAC-Nitrile is solid, has a limited solubility (432.2 mg/l at pH 6.7 and 20 °C) and is 100% pure.

Consequently the test media were prepared by adding the respective amounts test item to empty glass vessels, addition of Algal medium, overnight stirring and sterile filtration.

The loading rates were 3.13, 6.25, 12.5, 25.0, 50.0, and 100 mg/l.

Three parallel test vessels were used for each test concentration of the test item and six vessels for the blank controls.

The concentrations of PAC-Nitrile in the test medium were measured by HPLC analysis at the beginning and after 24, 48 h and 72 h of exposure. These analyses revealed that the concentrations of test item were rather stable over the whole 72 h period, but that the lowest test concentration (3.13 mg/l) was not within 80-120% of the nominal loading rate. Therefore, the effective concentrations ErCx/EyCx were assessed based on the geometric mean of the measured concentrations of the test item over the whole 72 h test period.

The results of the growth rate (r) and yield (y) inhibition of PAC-Nitrile to the green algae Desmodesmus subspicatus are summarized in the following table showing EC values and 95% confidence limits (cl) based on the geometric mean of the measured concentrations.

The 72 h ErC50 and EyC50 values of PAC-Nitrile on the green alga Desmodesmus subspicatus were 44.7 mg/l and 20.1 mg/l, respectively. These values are based on geometric mean of the measured concentrations.