4-(tricyclo[5.2.1.02,6]dec-8-ylidene)butyraldehyde

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 6 December 2016 and 10 March 2017.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-(tricyclo[5.2.1.02,6]dec-8-ylidene)butyraldehyde

EC Number:

250-078-7

EC Name:

4-(tricyclo[5.2.1.02,6]dec-8-ylidene)butyraldehyde

Cas Number:

30168-23-1

Molecular formula:

C14H20O

IUPAC Name:

4-[(8Z)-tricyclo[5.2.1.0^{2,6}]decan-8-ylidene]butanal

Test material form:

liquid

Specific details on test material used for the study:

Test Item: Dupical
Batch Number: VE00422788
Purity: 98.0%
Appearance: colourless to pale yellow liquid
Expiry date: 2017-01-28
Recommended storage: Dry, well-ventilated, hermetically sealed at ambient temperature (10 - 30 °C), protected against light.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

All concentration levels of the test item and the control were analytically verified via GC-FID in fresh media at the start of the exposure and at water renewal (0 and 24 hours) and in old media at renewal and at the end of the exposure (24 and 48 hours).

Test solutions

Vehicle:

yes

Remarks:

0.1 mL/L acetone used as solvent. Solvent Control incorporated in to study set-up.

Details on test solutions:

Test item spiked in solvent due to intrinsic instability of Aldehydes in aqueous systems, where the Parent is likely to oxidise rapidly to the Carboxylic Acid derivative which renders the use of more traditional preparation of water saturated solutions more problematic due to potential build-up of high amounts of metabolites during the preparation period.
Five nominal test item concentrations in the range 0.100 to 1.60 mg/L were prepared individually in a geometric series with a separation factor of 2 and tested. For each test item concentration a separate stock solution was prepared in acetone (solvent) at the start of the exposure and at renewal (0 and 24 hours).

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Test system: Daphnia magna STRAUS (Clone 5)
Reason for the selection of the test system: Daphnia magna is the preferred species in accordance with the test guidelines and is bred at the test facility.
Origin: Niedersächsischer Landesbetrieb für Wasserwirtschaft, Küsten- und Naturschutz, An der Scharlake 39, 31135 Hildesheim, Germany
Breeder: Noack Laboratorien GmbH, Käthe-Paulus-Str. 1, 31157 Sarstedt, Germany
Culture: In glass vessels (2 - 3 L capacity) with approximately 1.8 L culture medium, at 20 ± 2 °C, in an incubator, 16 hours illumination, light intensity of max. 1500 lx
Culture medium: Elendt M4, according to OECD 202, Annex 3 (2004), modified to a total hardness of 160 to 180 mg CaC03/L, is used.
Culture feeding: The culture daphnids are fed at least 5 times per week ad libitum with a mix of unicellular green algae, e.g. Pseudokirchneriella subcapitata and Desmodesmus subspicatus, with an algae cell density of > 10,000,000 cells/mL. The algae are cultured at the test facility.
Origin of the food algae: Sammlung von Algenkulturen (SAG), Pflanzenphysiologisches Institut der Universität Göttingen, Nikolausberger Weg 18, 37073 Göttingen, Germany

Study design

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

48 h

Test conditions

Test temperature:

18-22 °C, constant within ± 1 °C

pH:

Control : 7.45 - 8.91
Solvent Control : 7.43 - 8.73
0.0504 mg/L : 7.37 - 8.61
0.167 mg/L : 7.43 - 8.53
0.407 mg/L : 7.44 - 8.53
0.807 mg/L : 7.42 - 8.90
1.65 mg/L : 7.43 - 8.81

Dissolved oxygen:

Control : 7.64 - 9.28
Solvent Control : 8.24 - 9.02
0.0504 mg/L : 8.27 - 9.06
0.167 mg/L : 8.32 - 9.07
0.407 mg/L : 8.33 - 9.09
0.807 mg/L : 8.39 - 9.08
1.65 mg/L : 8.39 - 9.03

Nominal and measured concentrations:

Range finding (nominal): 1, 2 and 4 mg/L
Definitive test (nominal): 0.100 - 0.200 - 0.400 - 0.800 - 1.60 mg/L in a geometric series with a separation factor of 2.
Definitive test (geometric mean measured): 0.0504, 0.167, 0.407, 0.807 and 1.65 mg/L

Details on test conditions:

Test method: Based on the results of a preliminary range finding test (section 7.1), the study was performed with a semi-static test design with a renewal of the test solutions after 24 hours, since the measured concentrations did not remain stable over 48 hours under test conditions. Due to the high vapor pressure of the test item, a closed system (closed test vessels without headspace) was chosen for testing to reduce contact with air and losses of the test item by evaporation. The solvent acetone was used as it helps dissolving the test item and avoiding prolonged stirring periods.

Test vessels / volume: Sealed glass flasks (4.5 (ID) x 9.5 (H) cm) with screw caps (made from polypropylene) and gaskets made from aluminum foil were used. A test volume of approximately 130 mL was provided in each test vessel. There was no headspace in the test vessels..

Number of daphnids and replicates: 20 daphnids, divided into 4 replicates, each with 5 daphnids, were used per concentration level, solvent control and control.

Age of the daphnids at the start of the exposure: Less than 24 hours old daphnids from a healthy stock were used for the study. Juvenile daphnids were removed from the culture vessels at the latest 24 hours before the start of the exposure and discarded. The juveniles born within the following period of max. 24 hours preceding the exposure were used for the test. No first brood progeny was used for the test.

Acclimatization: Acclimatization of the daphnids was not necessary, because the dilution water was equivalent to the culture medium.

Application: The test vessels were filled up to the top with the test solutions. There was no headspace in the test vessels. The daphnids were inserted with a small amount of dilution water (start of the exposure) or test solution (water renewal) by pipette. Thereafter, the test vessels were closed immediately with screw caps.

Illumination (target): Diffuse light, light intensity of max. 1500 lx

Photoperiod (target): 16/8 hours light/dark cycle.

Feeding: The daphnids were not fed during the study.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate p.a. (Sigma)

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.573 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

95% CI : 0.508 - 0.647 mg/L

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.407 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

1.65 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

The percentage of immobility for the reference item potassium dichromate (Sigma-Aldrich, batch number MKBV0900V, purity 99.0%, CAS RN 7778-50-9)) was determined after 24 hours from 2017-01-12 to 2017-01-13. EC50 = 1.27 mg/L (95% CL 1.05 - 1.71 mg/L)

Any other information on results incl. tables

Validity Criteria

The study was performed according to OECD Guideline 202 (2004). The validity criteria were fulfilled:

• In the control group, no daphnids were immobilized or showed any signs of disease or stress, e.g. discoloration or unusual behavior such as trapping on the surface of the water, during the 48-hour test period (required: not more than 10% of the daphnids in the control).

• The dissolved O2 concentration in the 24-hour old media at the end of the exposure intervals was > or = 7.64 mg/L (required: > or = 3 mg/L at the test end of the exposure intervals) in the test vessels of all tested concentration levels, the solvent control and the control.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Based on the geometric mean measured concentrations of the test item, the 48 hours-ECso for Daphnia magna was 0.573 mg/L (95% confidence limits: 0.508 - 0.647 mg/L).

Executive summary:

In the acute immobilization test with Daphnia magna (STRAUS), the effects of the test item DUPICAL (batch number: VE00422788) were determined at the test facility according to OECD 202 (2004) from 2017-01-11 to 2017-01-15 with the definitive exposure phase from 2017-01-11 to 2017-01-13.

The study was conducted in a closed system (sealed glass flasks) without headspace, due to the volatility of the test item, to reduce contact with air and losses of the test item by evaporation.

The study was performed under semi-static conditions over a period of 48 hours, since the measured concentrations did not remain stable over 48 hours under test conditions in a preliminary range finding test.

In the definitive test the solvent acetone was used as it helps dissolving the test item and avoiding prolonged stirring periods. The test item is an aldehyde and thus likely to undergo significant oxidation in aquatic toxicity testing media. Aim of this procedure was to achieve sufficient exposure concentrations of the test item near the nominal concentrations. High amounts of metabolites of the test item should be avoided by keeping the preparation period of the test solutions as short as possible by using a solvent.

Five nominal test item concentrations in the range of 0.100 to 1.60 mg/L were prepared individually in a geometric series with a separation factor of 2 and tested. For each test item concentration a separate stock solution was prepared in acetone (solvent) at the start of the exposure and at renewal (0 and 24 hours). The test item concentrations were prepared by adding 0.1 mL/L of the stock solutions to the dilution water. The test item solutions were mixed thoroughly by manual agitation until the test item was completely dissolved. In addition, a control and solvent control (containg 0.1 mL/L acetone) were prepared and run in parallel to the test concentrations.

The concentration levels of 0.100 to 1.60 mg/L were visually clear throughout the exposure period.

Twenty daphnids (divided into 4 replicates with 5 daphnids each) were exposed to each concentration level and the control.

All concentration levels of the test item and the controls were analytically verified via GC-FID in fresh media at the start of the exposure and at renewal (0 and 24 hours) and in old media at renewal and at the end of the test (24 and 48 hours).

The measured concentrations of the test item were in the range of 99 to 113% of the nominal values in fresh media (0 and 24 hours) and 45 to 104% in 24-hours old media (24 and 48 hours). However, the measured concentrations of the test item in the lowest concentration level of 0.100 mg/L (nominal) were below the LOQ in the 24-hours old media (24 and 48 hours). This test concentration was below the ECo and NOEC determined for the test item.

Since the measured test item concentrations were not within the range of ± 20% of the nominal concentrations, the effect concentrations given in Table 1 are based on the geometric mean measured concentrations of the test item DUPICAL.

The validity criteria of the test guideline were fulfilled.

A clear dose-response relationship was observed for the test item. Following the 48 hour exposure, 100% and 90%, respectively, of the exposed daphnids were immobile at the nominal concentrations of 1.60 mg/L and 0.80 mg7L. No daphnis were immobilized nor demonstrated any documented sub- lethal effects at the two lowest test concentrations, 0.10 and 0.20 mg/L (nominal).

The 48 hour EC50, ECo and NOEC, based on the geometric mean measured concentrations, were determined to be 0.573 mg/L, 0.407 mg/L and 0.167 mg/L, respectively.