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

Sediment toxicity

Link to relevant study record(s)

Reference

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 225 (Sediment-Water Lumbriculus Toxicity Test Using Spiked Sediment)

Version / remarks:

2006

Deviations:

not specified

GLP compliance:

not specified

Remarks:

Published study from a peer-reviewed journal.

Analytical monitoring:

yes

Details on sampling:

SEDIMENT
- Sampling interval: Sediment samples were taken at the end of the test (28 days)

Vehicle:

yes

Remarks:

ethyl acetate

Details on sediment and application:

PREPARATION OF SPIKED SEDIMENT
- Details of spiking: The whole amount of sediment was treated with the test item.
- Equilibration time: 7 days
- Equilibration conditions: Test conditions
- Controls: Unspiked sediment
- Chemical name of vehicle: Ethyl acetate
- Concentration of vehicle in test medium (stock solution and final test solution): Not reported
- Evaporation of vehicle before use: Yes, for 24 hours

Test organisms (species):

Lumbriculus variegatus

Details on test organisms:

TEST ORGANISM
- Source: Lab culture of ECT Oekotoxikologie GmbH (Flörsheim, Germany)
- Breeding conditions: Worms were kept in continuously aerated 5 L aquaria filled with reconstituted water (pH-value: 7.9 to 8.4, conductivity: 540 μS/cm) and a sediment layer of 1 cm depth, containing pure quartz sand with a grain size between 0.1 and 0.4 mm. The culture was maintained at 20 ± 1 °C and the light dark rhythm was adjusted to 16:8 h.
- Age of animals at beginning of exposure: Not reported, worms of the same developmental status were used for the test.
- Food type: Tetramin
- Amount: ad libitum
- Frequency: Once a week

Study type:

laboratory study

Test type:

static

Water media type:

freshwater

Type of sediment:

artificial sediment

Limit test:

no

Duration:

28 d

Exposure phase:

total exposure duration

Test temperature:

20 ± 1 °C

pH:

7.9 to 8.4

Conductivity:

540 μS/cm

Nominal and measured concentrations:

0.08, 0.4, 2, 10 and 50 mg/kg dw sediment
< 0.05, 0.21, 1.47, 6.18, 51.5 mg/kg sediment dw (measured at day 28)

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 500 mL glass beakers (8 cm diameter), covered with a plastic cap.
- Sediment volume: Each beaker was filled with 40 g dw spiked artificial sediment.
- Overlying water volume: 200 mL
- Depth of sediment and overlying water: Sediment layer 1 cm deep, overlying water depth not reported.
- Aeration: yes
- Aeration frequency and intensity: Continuously aerated

EXPOSURE REGIME
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control / vehicle control: 4

OVERLYING WATER CHARACTERISTCS
- Type of water: Reconstituted water


CHARACTERIZATION OF ARTIFICIAL SEDIMENT
- Particle size distribution
- % sand: pure quartz sand with a grain size between 0.1 and 0.4 mm

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light and 8 hours dark

EFFECT PARAMETERS MEASURED: At the end of the test, the number and weight of the worms were recorded as endpoints. Once in a week, physical and chemical parameters of the overlying water such as temperature, pH-value, conductivity, and
nitrite and ammonium content were measured and recorded.

VEHICLE CONTROL PERFORMED: yes

Reference substance (positive control):

no

Key result

Duration:

28 d

Dose descriptor:

EC10

Effect conc.:

>= 51.5 mg/kg sediment dw

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

and weight

Remarks on result:

not determinable

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

>= 51.5 mg/kg sediment dw

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

and weight

Remarks on result:

not determinable

Details on results:

- Mortality of test animals at end of exposure period: Due to the fast degradation of dead worms in the sediment, mortality could not be measured.

Reported statistics and error estimates:

All data were tested for normality by the Kolmogorov-Smirnov test. As the data were normally distributed, significant differences compared to the solvent control were calculated using a one-way analysis of variance (ANOVA) followed by Dunn’s post hoc test.

Table 1. Nominal and measured test concentrations at the end of the test

Nominal concentration on day 0 (mg/kg sediment dw)	Measured concentration on day 28 (mg/kg sediment dw)	% Recovery on day 28
Control	not detectable	-
Solvent control	not detectable	-
0.08	< 0.05	-
0.40	0.21	55.1
2.00	1.47	76.9
10.0	6.18	64.9
50.0	51.5	108

Table 2. Reproduction and weight of Lumbriculus variegatus exposed to the test item in a 28-day sediment test (mean ± standard deviation; n = 4)

Measured concentration (mg/kg sediment dw)	Reproduction (number of worms per test vessel)	Dry weight (mg/worm)	Total biomass (mg)
Control	39.8 ± 12.7	0.59 ± 0.38	41.0 ± 19.0
Solvent control	34.3 ± 2.50	0.92 ± 0.23	39.5 ± 1.22
0.06	25.0 ± 4.40	1.16 ± 0.23	29.2 ± 7.92
0.21	23.5 ± 4.20	1.16 ± 0.27	27.1 ± 7.51
1.47	24.3 ± 5.12	1.33 ± 0.15	32.3 ± 8.15
6.18	22.3 ± 2.63*	1.19 ± 0.37	26.0 ± 6.89
51.5	23.5 ± 1.92	1.24 ± 0.24	29.2 ± 7.09

Validity criteria fulfilled:

yes

Remarks:

The observed factor of reproduction in the control groups with a value of 3.98 within 28 days (must be ≥ 1.80). At the end of the test, the pH ranged between 7.4 and 8.6 and dissolved oxygen level was always above 60% of air saturation volume.

Conclusions:

There were no significant effects on reproduction or biomass up to 51.5 mg/kg sediment dw, the highest concentration tested.

Executive summary:

The chronic toxicity of 4-methylbenzylidene camphor to Lumbriculus variegatus was determined in a 28 -day test under static conditions. Test organisms were exposed to five nominal concentrations of 0.08, 0.4, 2, 10 and 50 mg/kg sediment dry weight, alongside a control and solvent control. Four replicates were used for each treatment group and control, with each replicate containing 10 test organisms. The number and weight of the worms were determined at the end of the test. Test item concentrations were analysed on day 28 and measured concentrations were used for the reporting of results. There were no concentration dependent, significant effects on reproduction or biomass up to 51.5 mg/kg sediment dw, the highest concentration tested. This study is considered to be reliable with restrictions (Klimisch 2) as it was conducted according to OECD Guideline 225, with minor limitations in the reporting.

Description of key information

There were no significant effects on reproduction or biomass of Lumbricus variegatus up to 51.5 mg/kg sediment dw, the highest concentration tested, after 28 -day exposure to the test item.

Key value for chemical safety assessment

EC10, LC10 or NOEC for freshwater sediment:

51.5 mg/kg sediment dw

Additional information

The chronic toxicity of 3-(4'-methylbenzylidene)-camphor to Lumbricus variegatus was determined in a 28 -day test under static conditions. Test organisms were exposed to five nominal concentrations of 0.08, 0.4, 2, 10 and 50 mg/kg sediment dry weight, alongside a control and solvent control. Four replicates were used for each treatment group and control, with each replicate containing 10 test organisms. The number and weight of the worms were determined at the end of the test. Test item concentrations were analysed on day 28 and measured concentrations were used for the reporting of results. There were no significant effects on reproduction or biomass up to 51.5 mg/kg sediment dw, the highest concentration tested. This study is considered to be reliable with restrictions (Klimisch 2) as it was conducted according to OECD Guideline 225, with minor limitations in the reporting.

Furthermore the chronic toxicity of the test substance to hte gastropod mollusc Potamopyrgus antiopodarum was investigated in a 56 -day sediment exposure test under static conditions. Due to methodological deficiencies this study was assessed as not reliable (RL=3) and therefore disregarded for the chemical safety assessment.