Copper, [29H,31H-phthalocyaninato(2-)-N29,N30,N31,N32]-, (1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)methyl derivs.

Toxicity to aquatic plants other than algae

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic plants other than algae

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study with analytical monitoring.

Qualifier:

according to guideline

Guideline:

OECD Guideline 221 (Lemna sp. Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

The frond numbers were determined on day 3, 5 and 7. The dry weight of each replicate from test end was determined at test termination.

Vehicle:

no

Details on test solutions:

PREPARATION OF TEST SOLUTION
The test item is not easily soluble in test water. To avoid physical effects of undissolved test item, no concentrations above the solubility limit of the test item in test water were tested.
Therefore, suspensions of the test item were prepared separately by suspending test item in test water at loading rates of nominal 10, 3.16, 1.0, 0.317 and 0.1 mg test item/L. These suspensions were stirred for 24 hours to dissolve as much test item as possible. Then, the undissolved test item was separated by filtration with a cellulose acetate filter (0.45 µm). The resulting filtrates are the Water Soluble Fractions which served as test solutions. The test solutions were prepared just before introduction of the aquatic plants (= start of the test).

In the control, test medium was used without addition of the test item.

Test organisms (species):

Lemna gibba

Details on test organisms:

- Test organism: aquatic freshwater plant Lemna gibba G3
- The plants are cultured in the laboratories of ibacon under standardised conditions according to the test guidelines.
- The fronds introduced in the test were taken from ibacon's in-house laboratory culture.


CULTURING MEDIUM
- The 20XAAP medium recommended by OECD Guideline 221 was used as culturing medium as well as solvent for the test item.
- The pH was adjusted with 2 M HCl to 7.4. The test water was prepared 1 day before test start to allow pH to stabilise.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

7 d

Hardness:

3.55 mmol/L as Carbon hardness

Test temperature:

22 – 24°C

pH:

pH values at test start 7.5 to 7.8, at the end of the test 8.9 to 9.0;

Nominal and measured concentrations:

- Concentrations tested (nominal): Water soluble fractions (WSF), separately prepared from nominal loadings of 10, 3.16, 1.0, 0.317 and 0.1 mg test item/L and a control.

- The total organic carbon content was determined in all of the duplicate test media samples and in the duplicate control samples from both sampling times (0 hour and seven days). The measured values were uniform over time, ranging from 5 to 10 mg carbon/L (test media) and 5 to 8 mg carbon/L (control).
In view of the limited informative value of the TOC results, all reported effect data are based on nominal loading rates of the test item.

Details on test conditions:

TEST SYSTEM
- Replicates per treatment: 3
- Replicates per control: 3
- Glass vessels of 250 mL volume with approximately 200 mL test medium, covered with glass dishes.

FURTHER TEST CONDITIONS
- continious illumination with 8283 Lux (mean value) with a range of 7940 to 8520 lux.

Reference substance (positive control):

yes

Remarks:

3,5 dichlorophenol

Duration:

7 d

Dose descriptor:

EC10

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

7 d

Dose descriptor:

EC10

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

7 d

Dose descriptor:

EC50

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

7 d

Dose descriptor:

EC50

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Results with reference substance (positive control):

ErC50 = 7.68 mg/L (frond number)
ErC50 = 7.1 mg/L (dry weight)

Validity criteria fulfilled:

yes

Reference 2

Endpoint:

toxicity to aquatic plants other than algae

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to attached justification.

Reason / purpose for cross-reference:

read-across source

Duration:

7 d

Dose descriptor:

EC50

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

7 d

Dose descriptor:

EC50

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Description of key information

With high probability acutely not harmful to aquatic plants

Additional information

There are no studies available that assess the chronic toxicity of the test substance to aquatic plants. However, as the test substance belongs to the substance group of Phthalocyanines whose group members resemble in their chemical structure as well as in their phys-chem properties, a read-across approach was used to cover this endpoint.

The acute toxicity of Phthalocyanines to Lemna gibba was investigated by a test on CAS 59160-79-1 according to OECD 221. The study was conducted according to GLP and the exposure lastet 7 days. Acute toxicity (frond number) resulted in EC50 > 10 mg/L [Ibacon 2015].