2-Ethylhexyl trans-4-methoxycinnamate

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:

experimental study

Adequacy of study:

key study

Study period:

10/01/2000-17/08/2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study according to international guideline (OECD Guideline 201) under GLP conditions, validity criteria met.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Remarks on exposure duration:

As 2-Ethylhexyl 4-methoxycinnamate was expected to degrade by photolysis, the test period included a pre-exposure period of 24 hours in the dark

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

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.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

65 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Within range of 19 - 230 mg/L

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

The study included sampling at all concentrations for analysis of actual exposure concentrations at the start of the test, after 24 h and 48 h and at the end of the test. Interpretation of the analytical data was not possible with respect to exposure concentrations, as most concentrations decreased below detection.

Validity criteria fulfilled:

yes

Conclusions:

The toxicity of 2-Ethylhexyl 4-methoxycinnamate towards Selenastrum capricornutum was investigated: the 72h-NOEC for growth rate was found to be 32 mg/L, the 72h-EC50 for growth rate was found to be >100 mg/L. These values are based on the nominal loadings of the WAFs tested.

Executive summary:

The toxicity of 2-Ethylhexyl 4-methoxycinnamate towards Selenastrum capricornutum was investigated according to OECD Guideline 201 under GLP conditions. The 72h-NOEC for growth rate was found to be 32 mg/L, the 72h-EC50 for growth rate was found to be >100 mg/L. These values are based on the nominal loadings of the WAFs tested, because interpretation of the analytical data of the samples collected at 24 h and 48 h and at the end of the test was not possible, as most concentrations decreased below detection. pH values in the controls increased more than the maximum of 1.5 units mentioned in OECD Guideline 201.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Test procedure conducted according to OECD guideline 201.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Analytical monitoring:

no

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Nominal and measured concentrations:

Nominal test concentrations (mg/L): 6.25, 12.5, 25, 50, 100, control
dilution factor 2

Details on test conditions:

Determination of mean fluorescence: 0, 24, 48, 72 h
Concentration control analysis: not performed since the detection limit of analytical method (1 mg/L) was beyond the water solubility (0.041 mg/L) of the test substance.

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

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:

EC90

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Biomass:

EbC10 (72 h) = 74.8 mg/L

EbC50 (72 h) > 100 mg/L

EbC100 (72 h) > 100 mg/L

Description of key information

Two studies with algae result both in 72h-EC50 (growth rate) > 100 mg/L loading (OECD 201).

The 72h-NOEC is > 32 mg/L in one test and the EC10 > 100 mg/L in the other.  

Additional information

In both studies, the test substance was tested above its water solubility limit. Therefore, the test concentrations should be interpreted as a loading rate. No effects were observed at levels far above the water solubility at loading rates of above 32 or 100 mg/L:

Pseudokirchneriella subcapitata  (OECD 201, GLP, reliability 1) (Bogers 2000)

tested as a WAF 10 100 mg/L loading, with 24h-pre-exposure period in the dark in view of photodegradability of the test substance

• 72h-NOEC > 32 mg/L (growth rate)
• 72h-EC50 > 100 mg/L (growth rate)
• Test conc. after 96 h (after 72-h of light) < 0.001 mg/L

Scenedesmus subspicatus = Desmodesmus subspicatus (OECD 201, GLP, reliability 1) (BASF 2001)

• 72h-EC10 > 100 mg/L

• 72h-EC50 > 100 mg/L
• No control analysis since water solubility limit was below the detection limit of the analytical method.

The first study (Bogers 2000) is identified as the key test; it has reliability 1 and sufficient details are available.