Benzoic acid, 2-amino-5-fluoro-, methyl ester

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: GLP- and Guideline-Study with no or minor deficiencies.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

EC Directive 92/69/EC Method C.3. Official Journal of the European Communities No. L383A/179

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

methyl 2-amino-5-fluorobenzoate

EC Number:

608-681-1

Cas Number:

319-24-4

Molecular formula:

C8 H8 F N O2

IUPAC Name:

methyl 2-amino-5-fluorobenzoate

Test material form:

other: yellowish solid

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Details on test solutions:

Stock solution: 200 mg/L, freshly prepared with dilution water
Dispersion treatment: 2 min ultrasound at room temperature
Solvent: None
Test concentrations: 3.13 - 6.25 -12.5 - 25 - 50 -100 mg/L
Light intensity: Nominal:60 -120 µE/M2*S Actual: mean value: 62.4 µE/m2*s
Test design: Three replicates per test concentration and six control replicates

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Desmodesmus subspicatus CHODAT SAG 86.81; fresh stocks were prepared every month on Z-Agar; Light intensity amounted 35 - 70 ME/m2*s for 24 h per day

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

After 72 hours 0.5 ml algae suspension from the concentrations 25-100 mg/L and control were transferred to 10 ml untreated dilution water and allowed to grow further 4-7 days to determine wether the effect of the test item was reversible.

Test conditions

Test temperature:

23 ± 2 °C

pH:

8.02-8.59

Nominal and measured concentrations:

Nominal concentrations:
3.13- 6.25-12.5,25-50-100 mg/L

Details on test conditions:

24 hours/d light

Reference substance (positive control):

yes

Remarks:

Potassium dichromate p.a. (MERCK).

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

21.6 - 24.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 2

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

30.8 - 34.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass and growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

12.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass and growth rate

Results with reference substance (positive control):

The acute toxicity of potassium dichromate to the unicellular freshwater green alga Desmodesmus subspicatus was determined over a period of 72 h from November 25 to 28, 2003. The EC50 -values of the reference item potassium dichromate after 72 h met the validity criteria according to EC Directive 92/69/EC Method C.3 Annex 2 (prescribed ranges are 0.20 -0.75 mg/L and 0.60 -1.03 mg/L potassium dichromate for inhibition of biomass growth and rate-related inhibition, respectively).

Reported statistics and error estimates:

NOEC and LOEC were determined by calculation of statistical significance of biomass integrals and growth rates. The BONFERRONI t-test was carried out for the determination of statistically significant differences compared to control replicates. When running a BONFERRONI t-test a Normality test and Homogeneity test were done first. P-values for both were 0.05. The a-value for BONFERRONI t-test was a=0.05.
Ebc50-values. ErC50-values and confidence intervals after 72 h were calculated by probit analysis. Probit values were taken from WEBER (1986). Confidence intervals were calculated according to a standard procedure (BREITIG &TUMPLING 1982).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this study 2-Amino-5-fluorbenzoesauremethylester was found to inhibit the growth of the freshwater green alga Desmodesmus subspicatusat nominal concentrations > 25 mg/L (biomass growth and growth rate). The EC50-values with 95 % confidence intervals for inhibition of biomass growth (EbC50) and specific growth rate (ErC50) after 72 h were 23.1 (21.6 - 24.7) and 32.4 (30.8 - 34.1) mg/L, respectively.
Inhibition effects were found to be reversible at 25 to 100 mg/L. All effect levels are given based on nominal concentrations of the test item 2-Amino-5-fluorbenzoesauremethylester.