4-trans-Methoxy-4-trans-propyl-[1,1-bicyclohexyl]

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

ANALOGUE APPROACH JUSTIFICATION
Please refer to the attached read across justification in section 13

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-09-09 to 2009-09-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Version / remarks:

adopted March 23, 2006

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test medium (reconstituted water and test material) was freshly prepared. Therefore, the calibrated flask with test material and vehicle (reconstituted water) was treated in an ultrasonic device for 1 hour. Subsequently, the preparation was stirred with a magnetic stirrer for further 23 hours. Afterwards, the formulation was given through a nutsch filter (pore size 10-16 µm) and the filtrate was used for the study.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

- Common name: green algae
- Strain: strain No. SAG 86.81
- Source: Sammlung von Algenkulturen, Pflanzenphysiologisches Institut der Universität Göttingen

ACCLIMATION
- Culturing media and conditions: same as test
- Any deformed or abnormal cells observed: no

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Hardness:

250 mg CaCO3/L

Test temperature:

21-22 °C

pH:

start of experiment: 7.9 ± 0.1
end of experiment: 9.6 ± 1.6

Dissolved oxygen:

saturated

Nominal and measured concentrations:

Nominal concentration of 100 mg/L (limit test); due to very low water solubility and the fact that the study was a limit test, no further analysis was initiated.

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Type: closed
- Material, size, fill volume: glass, 300 mL, 100 mL
- Aeration: none
- Initial cells density: 10,000 cells/mL
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates):1

GROWTH MEDIUM
- Standard medium used: yes, reconstituted water

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: same as growth medium

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: continuous illumination
- Light intensity and quality: ca. 8000 Lux

EFFECT PARAMETERS MEASURED:
- Determination of cell concentrations: The algae cell densities were determined with an electronic particle counter (Coulter, Z2).

TEST CONCENTRATIONS
- Justification for using less concentrations than requested by guideline: In a pretest under static conditions, inhibition of the growth rate of the algae, Desmodesmus subspicatus, was not observed at a concentration of 100 mg/L, nominally.

Reference substance (positive control):

yes

Remarks:

potassium dichromate from separate study

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Validity criteria fulfilled:

yes

Conclusions:

An aqueous preparation of 100 mg/L (nominal) of the test item revealed no toxic effect in the test system. The 72 hours EC50 could not be determined, because it exceeded the maximum solubility of the test material in reconstituted water (EC50 > 0.06 mg/L).

Executive summary:

The purpose of this aquatic toxicity study was to evaluate the inhibitory effect of the test material on the growth of the unicellular green algae species, Desmodesmus subspicatus. The inhibition of the growth in relation to the control was determined over a period of 72 hours in a test according to Council Regulation (EC) No. 761/2009 and OECD Guideline 201. The study design included one control group and one test material group with six replicates, each containing 100 mL reconstituted water or test medium and about 10,000 cells/mL at the start of the experimental phase. The study was performed as a limit test in an open static test system. The algae were exposed to a filtrate of nominal 100 mg/L. The growth of the algae was calculated after 24, 48, and 72 hours exposure in the test medium. All validity criteria were met. The analysis of the saturated aqueous preparation revealed that the water solubility of the test item in reconstituted water was < 0.06 mg/L. The test material concentration in the aqueous medium could not be quantified since it was below the limit of quantification. For the test item, the following EC₅₀ values and no effect concentration for Desmodesmus subspicatus were determined:

72 h EC₅₀ > 100 mg/L

72 h EC₁₀ > 100 mg/L

Description of key information

The read-across substance was tested to Desmodesmus subspicatus in an open static test system according to OECD 201 (2006). Under the given conditions of this study (reference 6.1.5-1) the 72-h ErC₅₀ value and the 72-h NOEC were determined to be > 100 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

For this endpoint a one-to-one read across was performed to a chemical similar compound of the same chemical class with a comparable physicochemical profile and similar data in biological relevant assays. The study was performed according to GLP and the methods applied are fully compliant with OECD TG 201.

The purpose of this aquatic toxicity study was to evaluate the inhibitory effect of the test material on the growth of the unicellular green algae species, Desmodesmus subspicatus. The inhibition of the growth in relation to the control was determined over a period of 72 hours in a test according to Council Regulation (EC) No. 761/2009 and OECD Guideline 201. The study design included one control group and one test material group with six replicates, each containing 100 mL reconstituted water or test medium and about 10,000 cells/mL at the start of the experimental phase. The study was performed as a limit test in an open static test system. The algae were exposed to a filtrate of nominal 100 mg/L. The growth of the algae was calculated after 24, 48, and 72 hours exposure in the test medium. All validity criteria were met. The analysis of the saturated aqueous preparation revealed that the water solubility of the test item in reconstituted water was < 0.06 mg/L. The test material concentration in the aqueous medium could not be quantified since it was below the limit of quantification. For the test item, the following EC₅₀ values and no effect concentration for Desmodesmus subspicatus were determined:

72 h EC₅₀ > 100 mg/L

72 h EC₁₀ > 100 mg/L