(2E)-2-(4-methylbenzylidene)heptanal

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Results derived from a valid read across, with adequate and reliable documentation / justification.

Justification for type of information:

The read across justification is presented in the overall Aquatic Endpoint Summary because in that document long-term toxicity to aquatic invertebrates and toxicity to aquatic algae is also included. The corresponding documentation file is also attached there.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.247 mg/L

Remarks on result:

other: Based on read across information

Validity criteria fulfilled:

yes

Remarks:

Justification for read across is presented in the overall aquatic endpoint summary.

Conclusions:

For Acalea an 48h-EC50 of 0.247 mg/L has been derived for Daphnia based on read across information from Hexyl Cinnamic Aldehyde.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from June 2003 to December 2004

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The test is conducted following OECD 202 guidelines and under GLP rules however, use of a solvent led to use of concentrations which caused floaters potentially confounding the toxicological results. Nevertheless this study can be considered fit for risk assessment purposes.

Justification for type of information:

Information used for read across to Acalea. The study record of HCA from the LR registrant is copied here, who finally derived an EC50 value of 0.247 mg/l.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Nominal concentrations selected for this study were 0.13, 0.25, 0.50, 1.0 and 2.0 mg a.i./L.
Concentration of samples collected in the pretest period were approximately 34 to 67% of nominal concentration.
Concentration of samples collected during the test were approximately 35 to 72% of nominal concentration.

- Sampling method: the samples were collected from one test chamber of each treatment and control group 2 days prior to the start of the test after conditioning the diluter for three days. Stock solution samples were collected on the day prior to test initiation to confirm the concentrations being delivered to the diluter. Samples also were collected from alternating replicate test chambers in each treatment and control group at test initiation and termination to measure concentrations of the test substance. All test solution samples were collected at mid-depth and placed in glass vials.

- Sample storage conditions before analysis:samples were analyzed immediately without storage.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Cladoceran
- Strain: Daphnia Magna
- Source: from cultures maintained by Wildlife International, Ltd., Easton, Maryland
- Age at study initiation (mean and range, SD): less than 24h old
- Weight at study initiation (mean and range, SD): no data
- Length at study initiation (length definition, mean, range and SD): no data
- Valve height at study initiation, for shell deposition study (mean and range, SD): not applicable
- Peripheral shell growth removed prior to test initiation: not applicable
- Method of breeding: Adult Daphnids were cultured in water approximately at the same temperature used during the test. They were held for at least 22 days prior to collection of the juveniles for testing.
- Feeding during test
- Food type: the neonates were not fed during the test
- Amount: not applicable
- Frequency: not applicable

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

128 mg/L as CaCO3

Test temperature:

water temperatures were within 20 ± 1 ºC

pH:

measurements of pH ranged from 8.1 to 8.3

Dissolved oxygen:

dissolved oxygen concentrations remained ≥7.9 mg/L (88% of saturation)

Salinity:

184 mg/L as CaCO3

Nominal and measured concentrations:

Concentrations as mg a.i./L

Nominal Concentration: 0.13; Measured Concentration: 0.0886 (0h) and 0.0796 (48h)
Nominal Concentration: 0.25; Measured Concentration: 0.159 (0h) and 0.150 (48h)
Nominal Concentration: 0.50; Measured Concentration: 0.358 (0h) and 0.353 (48h)
Nominal Concentration: 1.0; Measured Concentration: 0.622 (0h) and 0.562 (48h)
Nominal Concentration: 2.0; Measured Concentration: 0.690 (0h) and 0.690 (48h)

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.36 - < 0.59 mg/L

Nominal / measured:

estimated

Conc. based on:

act. ingr.

Remarks on result:

other: 95% confidence limits were 0.084 to 0.59 mg a.i./L

Details on results:

Concentraion
Control

Nominal (mg/L)	Measured Concentration (mg/L)	% Immobilisation 24 h	% Immobilisation 48 h
0	Control	0	5
0	Solvent Control	0	0
0.13	0.084	0	5
0.25	0.15	0	35
0.5	0.36	0	40
1	0.59	10	100
2	0.69	60	100

Validity criteria fulfilled:

yes

Conclusions:

The test substance was tested in a 48h flow-through acute toxicity test with daphnia magna following OECD 202 guidelines. EC50(48h) was found to be 0.247 mg a.i./L based on measured concentrations. While physical effects may be the cause of some immobilisation observed (floaters found in the test at all concentrations except the control) a 48 h EC50 for this test was determined and considered acceptable to evaluate the acute toxicity of the substance on invertebrates

Executive summary:

The Daphnia Magna was exposed to five concentrations of the test substance under flow-through conditions for 48 hours. Analysis of the test solutions at 0 and 48 hours indicated that the test substance was not stable in water, as evidenced by the measured concentrations that ranged from approximately 35 to 72% nominal.

Concentration response effects were observed in the study and while physical effects may be the cause of some immobilisation observed (floaters found in the test at all concentrations except the control) the EC50 obtained is believed to be acceptable for use in hazard assessment.

Based on the mean measured test concentrations, a 48 -hour EC50 value of 0.247 mg/L was calculated.

Description of key information

For Acalea an 48h-EC50 of 0.247 mg/L has been derived for Daphnia based on read across information from Hexyl Cinnamic Aldehyde.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.247 mg/L

Additional information

The experimental information from the source is presented here. The read across justification is presented in the overall Aquatic Endpoint Summary.

Hexyl Cinnamic Aldehyde and its short-term toxicity to Daphnia (copied from the Lead Registrant):

"The Daphnia Magna was exposed to five concentrations of the test substance under flow-through conditions for 48 hours. Analysis of the test solutions at 0 and 48 hours indicated that the test substance was not stable in water, as evidenced by the measured concentrations that ranged from approximately 35 to 72% nominal.

Concentration response effects were observed in the study and while physical effects may be the cause of some immobilisation observed (floaters found in the test at all concentrations except the control) the EC50 obtained is believed to be acceptable for use in hazard assessment.

Based on the mean measured test concentrations, a 48 -hour EC50 value of 0.247 mg/L was calculated".