(trans(trans))-4'-but-3-enyl-4-(4-methylphenyl)-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

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

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

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2000-08-18 to 2000-09-25

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:

2006

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

EEC, Directive 92/69/1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Details on sampling:

- Sampling: after 24, 48, or 72 hours

Vehicle:

no

Details on test solutions:

The test medium (reconstituted water and test item) was freshly prepared. The calibrated flask with test item and vehicle, reconstituted water, was treated in an ultrasound bath for 1 hour. Subsequently, the preparation was stirred with a magnetic stirrer for further 23 hours. Afterwards, the preparation was filtered through a filter funnel with a pore size of 10 - 16 µm. The filtrate was used for the study.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green unicellular algae
- Strain: SAG 86.81
- Source (laboratory, culture collection): "Sammlung von Algenkulturen, Pflanzenphysiologisches Institut der Universitat Gottingen"
- Method of cultivation: Prior to start the study, the algae were grown in reconstituted water as preculture and the growth rate was determined.

ACCLIMATION
- Acclimation period: none
- Culturing media and conditions (same as test or not):the same

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Hardness:

250 mg CaCO3

Test temperature:

22 - 23 °C

pH:

7.81 - 9.74

Nominal and measured concentrations:

Nominal concentration of 100 mg/L (limit test); due to very the 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: open - completely sealed with sterilized stoppers
- Material, size, headspace, fill volume: glass, 300 mL, 100 mL fill volume
- Aeration: none
- Initial cells density: 10000 algae cells/mL
- Control end cells density: 1188540 cells/mL
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

GROWTH MEDIUM
- Standard medium used: yes, reconstitution water prepared according to the guideline

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

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: no
- Photoperiod: continuously illuminated
- Light intensity and quality: 7500 to 9500 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

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

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

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Results with reference substance (positive control):

Regularly, a positive control test to check the test system is carried out with potassium dichromate.

Table 1: Cell density

	Cell density per mL					Growth inhibition (0 - 72 hours)
nominal		0 hour	24 hours	48 hours	72 hours	1a	1µt
0		10,000	51,030	241,791	1,230,633
		10,000	54,927	257,040	1,228,527
		10,000	52,740	242,420	1,106,460
	mean	10,000	52,899	247,084	1,188,540
100		10,000	59,130	319,209	1,268,460
		10,000	58,473	333,251	1,280,610
		10,000	60,210	324,411	1,260,117
	mean	10,000	59,271	325,624	1,269,729
Inhibition la			-14.9	-30.3	-11.3	-144	-1.4

I_a = inhibition of cell growth in percent

I_µt = Inhibition of growth rate in percent

-I_a = The growth of the algae was better in the test medium than in the control group.

A dose group with nominal 100 mg/L of the test item (maximal water solubility < 0 005 mg/L) revealed no aquatic toxicity in this test system.

An aqueous solution of nominal 100 mg/L of the test item revealed no effect for Desmodesmus subspicatus. The EC₅₀ exceeded the maximal water solubility (< 0.005 mg/L) of the test material and. thus, could not be determined in this test.

The following EC_x values and no effect concentration for Desmodesmus subspicatus were determined:

72 h EbC₅₀ = > 0.005 mg/L (nominal > 100 mg/L)

72 h ErC₅₀ = > 0.005 mg/L (nominal > 100 mg/L)

NOEC = > 0 005 mg/L (nominal > 100 mg/L)

 

Validity criteria fulfilled:

yes

Conclusions:

The test item was tested to Desmodesmus subspicatus in an open static test system according to OECD 201 (1984). Under the given conditions of this study the 72-h ErC50 value and the 72-h NOEC were determined to be > 100 mg/L.

Executive summary:

The influence of the test substance on the growth and growth rate of the green algae species Desmodesmus subspicatus was tested according to OECD 201 (1984) under GLP conditions. The study design included one control and one test item group with three replicates, each containing about 100 mL reconstituted water or test medium and 10000 cells/mL at the start of the experimental phase. The algae were exposed to a filtrate of nominal 100 mg/L and the study was performed as a limit test in an open static test system. The analysis of the saturated aqueous preparation revealed that the water solubility of the test substance in reconstituted water was < 0.005 mg/L and could not be determined analytically. The test material concentration in the aqueous medium could not be quantified since it was below the level of detection. Regularly, a positive control test to check the test system is carried out with potassium dichromate. The validity criteria of the test were met. Under the given conditions of this study the 72-h ErC50 value and the 72-h NOEC were determined to be > 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 (1984). 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.

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 influence of the test substance on the growth and growth rate of the green algae species Desmodesmus subspicatus was tested according to OECD 201 (1984) under GLP conditions. The study design included one control and one test item group with three replicates, each containing about 100 mL reconstituted water or test medium and 10000 cells/mL at the start of the experimental phase. The algae were exposed to a filtrate of nominal 100 mg/L and the study was performed as a limit test in an open static test system. The analysis of the saturated aqueous preparation revealed that the water solubility of the test substance in reconstituted water was < 0.005 mg/L and could not be determined analytically. The test material concentration in the aqueous medium could not be quantified since it was below the level of detection. Regularly, a positive control test to check the test system is carried out with potassium dichromate. The validity criteria of the test were met. Under the given conditions of this study the 72-h ErC50 value and the 72-h NOEC were determined to be > 100 mg/L (reference 6.1.5-1).