(3E)-1,7,7-trimethyl-3-(4-methylbenzylidene)bicyclo[2.2.1]heptan-2-one

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Analytical verification of test concentrations not conducted for the algal study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

not specified

Remarks:

Published study from a peer-reviewed journal.

Analytical monitoring:

no

Remarks:

No analytical verification of concentrations in algal study.

Vehicle:

yes

Remarks:

Ethanol

Details on test solutions:

Control: Dilution water
Solvent Control: Ethanol, maximum of 0.05% in test medium
Solvent concentration in test solutions was set to a maximum of 0.05% in the test medium for all tests

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Source: ECT Oekotoxikologie GmbH, Floersheim, Germany.

Test type:

static

Water media type:

freshwater

Remarks:

AAP algal medium

Limit test:

no

Total exposure duration:

72 h

Hardness:

Not reported

Test temperature:

20.5 ± 1 deg C

pH:

Not reported

Dissolved oxygen:

Not reported

Salinity:

Not applicable

Conductivity:

Not reported

Nominal and measured concentrations:

Nominal test concentrations: 0.5. 1.0. 2.0, 4.0, 8.0 mg/L

Details on test conditions:

TEST SYSTEM

Test vessel: 100 mL glass Erlenmeyer flasks
Test volume: 50 mL
Agitation: On a horizontal shaker at 110 rpm
No. of cells per replicate: 5x10^4
No.of vessels per concentration and solvent control (replicates): 3
No.of vessels per dilution water control (replicates): 5

Key result

Duration:

72 h

Dose descriptor:

IC10

Effect conc.:

0.81 mg/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Remarks on result:

other: 95% confidence intervals: 0.09 - 7.49 mg/L

Key result

Duration:

72 h

Dose descriptor:

IC50

Effect conc.:

7.66 mg/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Remarks on result:

other: 95% confidence intervals: 3.51 - 16.7 mg/L

Validity criteria fulfilled:

not specified

Remarks:

The publication did not specify whether the criteria were fulfilled and insufficient data were presented to determine this.

Conclusions:

Based on the nominal concentrations of the test item, the 72h IC50 for Desmodesmus subspicatus was 7.66 mg/L (95% confidence limits 3.51 - 16.7 mg/L). The 72h IC10 was 0.81 mg/L (95% confidence limits 0.09 - 7.49 mg/L).

Executive summary:

In the algal growth inhibition test with Desmodesmus subspicatus, the effects of the test item were determined according to OECD 201 (2006) guideline. The study was conducted under static conditions over a period of 72 hours with 5 concentrations of the test item (0.5, 1.0, 2.0, 4.0, 8.0 mg/L). The test included 5 replicates in the controls and 3 replicates for the solvent control (ethanol) and each test concentration. The concentrations of the test item were not analytically verified. Based on the nominal concentrations of the test item, the 72 hour IC50 for Desmodesmus subspicatus was 7.66 mg/L (95 % confidence limits: 3.51 - 16.7 mg/L). The 72 hour IC10 was 0.81 mg/L (95% confidence limits 0.09 - 7.49 mg/L). The study is considered to be reliable with restriction (Klimisch 2) as it was conducted according to guideline, however no analytical verification of test concentrations was performed and nominal tested concentration were above the water solubility of the test substance (WS = 1.08 mg/L).

Description of key information

Based on the nominal concentrations of the test item, the 72h IC50 for Desmodesmus subspicatus was 7.66 mg/L (95% confidence limits 3.51 - 16.7 mg/L). The 72h IC10 was 0.81 mg/L (95% confidence limits 0.09 - 7.49 mg/L).

Key value for chemical safety assessment

EC50 for freshwater algae:

7.66 mg/L

EC10 or NOEC for freshwater algae:

0.81 mg/L

Additional information

In the algal growth inhibition test with Desmodesmus subspicatus, the effects of the test item were determined according to OECD 201 guideline (2011). The study was conducted under static conditions over a period of 72 hours with 5 concentrations of the test item (0.5, 1.0, 2.0, 4.0, 8.0 mg/L). The test included 5 replicates in the controls and 3 replicates for the solvent control (ethanol) and each test concentration. The concentrations of the test item were not analytically verified. Based on the nominal concentrations of the test item, the 72 hour IC50 for Desmodesmus subspicatus was 7.66 mg/L (95 % confidence limits: 3.51 - 16.7 mg/L). The 72 hour IC10 was 0.81 mg/L (95% confidence limits 0.09 - 7.49 mg/L). The study is considered to be reliable with restriction (Klimisch 2) as it was conducted according to guideline, however no analytical verification of test concentrations was performed.