Acetic acid, oxo-, sodium salt, reaction products with ethylenediamine and phenol, iron sodium salts

Toxicity to aquatic plants other than algae

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic plants other than algae

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004-10-20 to 2004-12-15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 221 (Lemna sp. Growth Inhibition Test)

Version / remarks:

2002

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Stock solution: 184.2 mg test item/L, freshly prepared with dilution water
Dispersion treatment: Agitation
Test concentration (nom.): 184.2 mg test item/L

Test organisms (species):

Lemna minor

Details on test organisms:

TEST ORGANISM
- Common name, Strain: Duckweed, Lemna minor, Lemnaceae, Arales, Arecidae, Monocotyledonae
- Source (laboratory, culture collection): ÖKOTOX MOSER & PICKL GBR, Postfach 720207, D-70578 Stuttgart
- Method of cultivation: The species was bred in the testing facility. Density was kept low to prevent conglomerates of plants on the surface. At least once per week, plants were transferred to freshly prepared growth medium. Growth media and breeding vessels were autoclaved before use to enable the breeding of axenic cultures.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

7 d

Test temperature:

24 +/- 2 degree C

Nominal and measured concentrations:

nominal: 184.2 mg test item/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Crystallisation dishes with a volume of 500 mL, covered with glass tops and filled with 200 mL test solution were used in the test.
- No. of colonies per vessel: 3
- No. of fronds per colony: 4
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3


GROWTH MEDIUM
- Standard medium used: yes


OTHER TEST CONDITIONS
- Light intensity and quality: Continuous fluorescent light, 6500 - 10000 lx (corresponding to 85 - 125 uE ⋅ m-2 ⋅ s-1) on the surface of the test medium. Difference of light intensity at any measured incubation place was less than 15 % from the mean value.

Reference substance (positive control):

yes

Remarks:

Zinc chloride

Key result

Duration:

7 d

Dose descriptor:

EC50

Effect conc.:

> 184.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: n.a.

Duration:

7 d

Dose descriptor:

EC50

Effect conc.:

> 184.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass growth

Remarks on result:

other: n.a.

Duration:

7 d

Dose descriptor:

NOEC

Effect conc.:

>= 184.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

7 d

Dose descriptor:

LOEC

Effect conc.:

> 184.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass growth

Duration:

7 d

Dose descriptor:

NOEC

Effect conc.:

184.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass growth

Duration:

7 d

Dose descriptor:

LOEC

Effect conc.:

> 184.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

7 d

Dose descriptor:

EC50

Effect conc.:

> 184.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass dry weight

Remarks on result:

other: n.a.

Duration:

7 d

Dose descriptor:

LOEC

Effect conc.:

> 184.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass dry weight

Duration:

7 d

Dose descriptor:

NOEC

Effect conc.:

184.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass dry weight

Reported statistics and error estimates:

The NOEC and LOEC were determined by calculation of statistical analyses statistical significance of log biomass integrals, growth rates and
log biomass dry weight. One Way Analysis of Variance (ANOVA) and DUNNETT’S test (biomass integrals and growth rates) were carried out for the determination of statistically significant differences compared to control replicates. When running a One Way Analysis of Variance a Normality Test and an Equal Variance Test were done first. P-values for both Normality and Equal Variance Tests were 0.05. The α-value (acceptable probability of incorrectly concluding that there is a difference) was α=0.05. For log biomass dry weight equal variance test failed and DUNNETT’S test with TOXSTAT was carried out for the determination of statistically significant differences compared to control replicates.

Validity criteria fulfilled:

yes

Conclusions:

In this study the effects of the test item on the growth of the monocotyledon Lemna minor were tested. All effect levels are given based on nominal a.i. concentrations. No effects were found at the nominal limit concentration of 184.2 mg/L (log biomass integrals, specific growth rate and log biomass dry weight; 0 – 7 d).
The EC50-values for inhibition of log biomass growth (EbC50), specific growth rate (ErC50) and log biomass dry weight (EdwC50) were > 184.2 mg/L, the NOEC was 184.2 mg/L and the LOEC was > 184.2 mg/L.

Executive summary:

The effects of the test item on growth of the monocotyledon species Lemna minor were determined according to the principles of OECD-Guideline 221. The test item (batch number A050309024) contained 54.3 % FeNa-EDDHMA, a structural analogue of FeNa-EDDHA, from which 5.2 % is Fe chelated by o,o-EDDHMA. The aim of the study was to determine the effects of the test item on the growth of Lemna minor over 7 days under static exposure conditions. Based on a preliminary test, a limit test with nominal 184.2 mg test item/L was carried out. Three replicates were investigated for the test concentrations and the control. Frond numbers were assessed on days 0, 2, 5 and 7. Inhibition of log biomass growth, specific growth rate and log biomass dry weight were determined. The concentrations of the a.i. FeNa- EDDHMA were analysed on days 0 (freshly prepared solution) and 7 (old solution) via HPLC. The recovery rates of the active ingredient FeNa-EDDHMA was 97 % in the fresh solution and 88 % in the old solution supporting the use of nominal concentrations. Environmental parameters, water temperature and pH-value were determined to be within the acceptable limits.

The EC50-values for inhibition of log biomass growth (EbC50), specific growth rate (ErC50) and log biomass dry weight (EdwC50) were greater than 184.2 mg/L, the NOEC was 184.2 mg/L and the LOEC was greater than 184.2 mg/L.

Description of key information

EC50(7d) > 100 mg a.i./L (nominal) for growth rate of Lemna minor (OECD 221, read across)

NOEC(7d) >= 100 mg a.i./L (nominal) for growth rate of Lemna minor (OECD 221, read across)

Additional information

Read across to structural analogue FeEDDHMANa (CAS No. 149057-66-9). For justification of the read across see the read across justification document attached in chapter 13. The acute toxicity of FeNa-EDDHMA to Lemna minor was performed according to OECD guideline 221 under GLP. The 7d-EC50 values for inhibition of log biomass growth (EbC50), specific growth rate (ErC50) and log biomass dry weight (EdwC50) were > 100 mg a.i./L, the NOEC was >= 100 mg a.i./L and the LOEC was > 100 mg a.i./L.. The animals were exposed to the substance for 7 days in a static test system.