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Ecotoxicological information

Sediment toxicity

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Administrative data

Endpoint:
sediment toxicity: long-term
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2006
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006
Report Date:
2006

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 219 (Sediment-Water Chironomid Toxicity Test Using Spiked Water)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
The test vessels were observed three times per week to make a visual assessment of any behavioural difference compared with the control. During the period of expected emergence (normally starting at day 10 and lasting until day 25) a daily check of emerged midges was performed. The sex and number of emerging adults were recorded daily. Only the number of fully emerged male and female midges was counted. The number of visible pupae which have failed to emerge was counted separately. The study was terminated after 28 days. The physico-chemical parameters were recorded in all test vessels at the start and the end of the test. These parameters were also recorded once a week for the duration of the test in all test vessels.

Test substrate

Vehicle:
yes
Details on sediment and application:
The artificial sediment (based on the artificial soil used in OECD Guideline 207) will be prepared using the following materials:
4-5% sphagnum peat (approximately pH 5.5-6.0), 20% kaolin clay (kaolinite content above 30%); 75-76% quartz sand (fine sand with more than 50% of the particles between 50 and 200 microns), approximately 1% calcium carbonate, precipitated extra pure, organic carbon content of the final mixture should be 2% (± 0.5%) and is to be adjusted by the use of appropriate amounts of peat and sand.

Test organisms

Test organisms (species):
Chironomus sp.
Details on test organisms:
-Species/strain
Chironomus riparius (Diptera,Chironomidae)

-Source
The egg masses used to start the culture were taken from an in-house culture of the Federal Biological Research Centre for Agriculture and Forestry, Institute for Ecotoxicology and Ecochemistry in Plant Protection, Kleinmachnow, Germany

-Culture conditions
Larvae were reared in crystalline dishes. Fine quartz was spread in a thin layer over the bottom of the container. A suitable medium was added to a depth of several cm. The larval rearing vessles were held in a suitable cage which prevented escape of the emerging adults. The larval rearing vessels were checked daily for deposition of the gelatinous egg masses. If present, the egg masses were transferred in new culture vessels.

-Age
1 to 3 days old, first larval stage

-Food
During the culture phase Chironomus larvae were fed every second or third day (ad libitum) with a flake food, at approx. 250 mg per vessel and day. During the experimental phase larvae were fed every day with 1 mg fish-food (Tetra Min®) per larvae.

-Pretreatment
Four days before application (application = day 0) some egg masses were taken from the cultures and deposited into small vessels in culture medium. Larvae of the first larval stage (1-3 days old) were allocated randomly to each test vessel 24 h before the application of the test substance

Study design

Study type:
laboratory study
Test type:
static
Water media type:
freshwater
Type of sediment:
artificial sediment
Limit test:
yes
Exposure duration
Duration:
28 d
Exposure phase:
total exposure duration

Test conditions

Hardness:
Total hardness = 140-268 mg/L (as CaCO3) correwsponding to 7.8 - 15°dH
Test temperature:
20°C +/- 2°C
pH:
7.3 – 8.3
Dissolved oxygen:
6.1 – 9.0 mg/L
Salinity:
Source: dechlorinated drinking water and deionised water
Details on test conditions:
TEST SYSTEM
Test type: Static
Volume of test vessels: 2 L glass-beakers measuring 12 cm in diameter. The test vessels were prepared one week before the study started and were acclimatised under the test conditions. The test vessels contained 2.5 cm of sediment (350 g wet sediment) and a water column of 10 cm (1000 mL medium). The volume of added water was recorded and the volume level at each vessel was marked outside on the test vessel.
Volume/animal: 40 mL/test organism
Number of animals/vessel: 25 organisms
Number of vessels/ concentration: 4 vessels/concentration
Test performed in closed vessels due to significant volatility of TS: No


TEST CONDITIONS
Test temperature: 20°C ± 2°C
Preparation of test vessels: The test vessels contained 2.5 cm of sediment (350 g wet sediment) and a water column of 10 cm (1000 mL medium)
Aeration : Before use the water was slightly aerated for at least 30 minutes. For aeration an aquarium pump was connected by means of a flexible silicon tube to a Pasteur pipette entering a hole in the cover of each test vessel. Air-flow of 1-2 bubbles/sec was directed. When adding the larvae and also for the following 24 hours, the aeration of the water was stopped.
Intensity of irradiation: Approx. 900 Lux
Photoperiod:Photoperiod of 16 hours light per day
Feeding regime: During the culture phase Chironomus larvae were fed every second or third day (ad libitum) with a flake food, at approx. 250 mg per vessel and day. During the experimental phase larvae were fed every day with 1 mg fish-food (Tetra Min®) per larvae
Type of water:Dechlorinated drinking water and deionised water

Results and discussion

Effect concentrationsopen allclose all
Duration:
28 d
Dose descriptor:
NOEC
Effect conc.:
0.063 other: C30-001:days
Nominal / measured:
not specified
Conc. based on:
not specified
Basis for effect:
mortality
Duration:
28 d
Dose descriptor:
LC50
Effect conc.:
0.546 other: C30-001:days
Nominal / measured:
not specified
Conc. based on:
not specified
Basis for effect:
mortality
Duration:
28 d
Dose descriptor:
LC100
Effect conc.:
1.05 other: C30-001:days
Nominal / measured:
not specified
Conc. based on:
not specified
Basis for effect:
mortality
Key result
Duration:
28 d
Dose descriptor:
NOEC
Effect conc.:
0.093 other: mg/kg sediment wwt
Nominal / measured:
meas. (TWA)
Conc. based on:
not specified
Basis for effect:
mortality
Remarks on result:
other: Time weighted geometric mean measured NOEC (calculated according to Annex 2 of the OECD 23, 2000)
Details on results:
The initial concentrations of test substance was :
Range-finding test: 0.01, 0.1, 1, 10, and 100 mg Piperonyl Butoxide/L
Definitive test: 0.0602, 0.0956, 0.153, 0.245, 0.392, 0.626, and 1.00 mg Piperonyl Butoxide /L


- Mortality of test animals at end of exposure period:
- Total mass of test animals at beginning of test:
- Changes in body weigthH58 of live adults (% of initial weight) at end of exposure period:
- No. of offspring produced:
- No. of emerged male and female midges (per vessel and per day):
- No. of pupae failing to emerge (per vessel and per day):
- Percent emergence per replicate and test concentration:
- Mean development rate of fully emerged midges (per replicate and treatment rate; male and female midges pooled):
- Mean individual dry weight of larvae (per larvae and per instar):
- Morphological abnormalities:
- Behavioural abnormalities:
- Other biological observations:

Applicant's summary and conclusion

Conclusions:
At the end of the test after 28 days most of the test item was found in the sediment.
The time weighted geometric mean measured NOEC (calculated according to Annex 2 of the OECD 23, 2000) was 0.0933 mg/kg wwt.