Imidazolium compounds, 2-C17-unsatd.-alkyl-1-(2-C18-unsatd. amidoethyl)-4,5-dihydro-N-methyl, Me sulfates

Sediment toxicity

Link to relevant study record(s)

Reference

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2021-04-26 to 2021-08-18 (final report date xx-xx-xxxx)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

October 2007

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Test item concentration and the control were confirmed by analytical verification via LC-MS/MS on day 0, 7 and 28 using additional replicates, each. Determination of the test item will be performed for the sediment, pore water and the overlying water.

Vehicle:

no

Details on sediment and application:

PREPARATION OF SPIKED SEDIMENT
- Method of mixing and details of spiking: The respective test item amounts were weighed, dispersed in demineralised water and added to the artificial sediment. Additional demineralised water was added to adjust the humidity of the artificial sediment to a moisture of 30 %. Subsequently, the test medium was mixed thoroughly to ensure a homogenous distribution.
- Equilibration time: 2 days
- Equilibration conditions: Test vessels were prepared 2 days prior to the insertion of the test organisms. The treated sediment was filled into the glass beakers, and water was added to the beakers without disturbing the sediment, and aeration was provided.
- Controls: Overlying water and artificial sediment without test or reference item

Test organisms (species):

Lumbriculus variegatus

Details on test organisms:

TEST ORGANISM
- Common name: California blackworms; blackworms; mudworms
- Strain/clone: Lumbriculus variegatus (Müller)
- Justification for species other than prescribed by test guideline: Lumbriculus variegatus is a recommended species according to the guideline.
- Source: Bundesanstalt für Gewässerkunde (BfG), Am Mainzer Tor 1, 56068 Koblenz, Germany
- Details on collection:
- Age of parental stock (mean and range, SD):
- Breeding conditions: Breeding is performed at the test facility at 20 +/- 2 °C and diffuse light (100 - 500 lx, 16 h photoperiod daily). The dissolved oxygen concentration is > 70 % of the air saturation value corresponding to 6.2 mg O2/L. Breeding Medium consists of quartz sand in reconstituted water. TetraMin® flake food (TETRA) is provided twice per week.
- Handling of egg masses and larvae:
- Age of animals at beginning of exposure: The worms were synchronized about 10 - 14 days prior to test start to minimize uncontrolled reproduction and regeneration.
- Feeding during test
-- Food type: Powder of Urtica dioica (stinging nettle, HEINRICH KLENK GMBH & CO KG, 97525 Schwebheim, Germany) mixed into the sediment
-- Amount: 0.4 – 0.5 % of the sediment dry weight
-- Frequency: once at the day of application

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

Nominal and measured concentrations:

Nominal: 62.5 — 125 — 250 — 500 — 1000 mg a.i./kg soil dry weight. The measured concentrations of the test item in the sediment were in the range from 104% to 114% at day 0, from 108% to 118% at day 7 and from 107 to 119% of the nominal concentrations at day 28. Minor recoveries of the concentrations of the test item in the aqueous phase and pore water could be determined. The Control samples were < LOQ.

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 250 mL glass beakers (6 cm diameter)
- Weight of wet sediment with and without pore water: About 45 g sediment dry weight
- Overlying water volume: Same as for holding, amount of 150 mL.
- Depth of sediment and overlying water: ca. 1.0 - 3.0 cm from the ground
- Aeration: yes
- Aeration frequency and intensity: Gentle aeration via Pasteur pipettes
- Replacement of evaporated test water, if any: Water levels will be topped up with demineralised water at least once weekly during the study to compensate losses due to evaporation.

EXPOSURE REGIME
- No. of organisms per container (treatment): 10 synchronized worms (similar physiological state) chosen randomly and inserted per replicate. No worms in the additional replicates for analytical measurement on day 0.
- No. of replicates per treatment group: 4 replicates per limit test item concentration, 1 replicate each for water quality analyses and 1 additional replicate for analytical measurements on day 0, 7, 28, each.
- No. of replicates per control: 6
- Feeding regime: mixed into the sediment at the day of application
- Type and preparation of food: Powder of Urtica dioica (stinging nettle, HEINRICH KLENK GMBH & CO KG, 97525 Schwebheim, Germany)
- Amount of food: 0.4 – 0.5 % of the sediment dry weight.

OVERLYING WATER CHARACTERISTCS
- Type of water (e.g. deionized, ground water, sea water, Elendt medium acc. to OECD 219): reconstituted water, no further information in the draft report



CHARACTERIZATION OF ARTIFICIAL SEDIMENT
- 4 - 5 % peat (air-dried and finely ground)
- 20 % kaolin (content preferably > 30 %)
- 75 % quartz sand (> 50 % particles sized 50-200 µm)


OTHER TEST CONDITIONS

- Photoperiod: 16 h

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
number of surviving worms per replicate and the total dry biomass of worms per replicate

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Justification for using less concentrations than requested by guideline:
- Range finding study test concentrations: 0 - 10 - 100 - 1000
- Results used to determine the conditions for the definitive study: preliminary study
- Limit test concentrations: 0 - 1000
- Results used to determine the conditions for the definitive study: 34% mortality at limit test conc.; mean number of worms reduced to 1/3

Reference substance (positive control):

yes

Remarks:

A reference item study is performed once a year with Potassium chloride.

Key result

Duration:

28 d

Dose descriptor:

EC10

Effect conc.:

67 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: total number of worms / reproduction

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

250 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: total number of worms / reproduction

Key result

Duration:

28 d

Dose descriptor:

EC10

Effect conc.:

551 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

500 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Summary of all Effects, based on nominal concentrations

Effects	test item [mg a.i./kg sediment dry weight]
LOEC Total number of worms/Reproduction	500
NOEC Total number of worms/Reproduction	250
EC Total number of worms/Reproduction (95 % Confidence Interval)	EC10:      67.0 (n.d.) EC20:      310 (n.d.) EC50:      n.d.
LOEC Biomass	1000
NOEC Biomass	500
EC Total Biomass per replicate (95 % Confidence Interval)	EC10:      551 (207 - > 1000) EC20:      707 (262 - > 1000) EC50:   > 1000 (265 - > 1000)

n.d. = not determined due to mathematical reasons

Validity criteria fulfilled:

yes

Remarks:

- The oxygen concentration in the overlying water was ≥ 30% of the air saturation value (2.7 mg/L); - The pH-value was between 6 and 9 in the overlying water; - In the control, the average number of living worms / replicate increased by a factor >= 1.8

Conclusions:

After 28 days of exposure, the test item induced no mortality in any test item concentration.
The total number of worms and thus the reproduction did not statistically significantly differ compared to the control in the test item concentrations 62.5 to 250 mg a.i./kg sediment dry weight. However, at the test item concentrations 500 and 1000 mg a.i./kg sediment dry weight the total number of worms was statistically significantly reduced.
Compared to the control, the total biomass per replicate was not statistically significantly different at the test item concentrations 62.5 to 500 mg a.i./kg sediment dry weight. However, at the test item concentration 1000 mg a.i./kg sediment dry weight the total biomass per replicate was statistically significantly reduced.

Executive summary:

The effects of the test item on the oligochaete Lumbriculus variegatus in a water-sediment system were determined under static conditions.
The study was carried out according to OECD Guideline 225 (2007). The test duration was 28 days from the insertion of the test organisms. The study was performed by spiking artificial sediment with the test item concentrations 62.5 – 125 – 250 – 500 – 1000 mg a.i./kg sediment dry weight. A control using untreated artificial sediment was set up. Six replicates per control and four replicates per test item concentration were set up for biological investigations.  
Analytical evaluation of the test item PC-2020-932 and the control was carried out via LC-MS/MS for sediment layer, aqueous phase and pore water on day 0, day 7 and day 28 using additional replicates. The measured concentrations of the test item in the sediment were in the range from 104% to 114% at day 0, from 108% to 118% at day 7 and from 107 to 119% of the nominal concentrations at day 28. Minor recoveries of the concentrations of the test item in the aqueous phase and pore water could be determined. The Control samples were < LOQ.

After 28 days of exposure, test item induced no mortality in any test item concentration.
The total number of worms and thus the reproduction did not statistically significantly differ compared to the control in the test item concentrations 62.5 to 250 mg a.i./kg sediment dry weight. However, at the test item concentrations 500 and 1000 mg a.i./kg sediment dry weight the total number of worms was statistically significantly reduced.
Compared to the control, the total biomass per replicate was not statistically significantly different at the test item concentrations 62.5 to 500 mg a.i./kg sediment dry weight. However, at the test item concentration 1000 mg a.i./kg sediment dry weight the total biomass per replicate was statistically significantly reduced.
All validity criteria were fulfilled.

Results Synopsis

 

NOEC_{total number of worms/reproduction}:  250 mg a.i./kg sediment dry weight

LOEC_{total number of worms/reproduction}:  500 mg a.i./kg sediment dry weight

 

NOEC_biomass:  500 mg a.i./kg sediment dry weight

LOEC_biomass:  1000 mg a.i./kg sediment dry weight

Description of key information

Draft study report, according to OECD test guideline 225, the oligochaete Lumbriculus variegatus was exposed to artificial sediment with the test item concentrations 62.5 – 125 – 250 – 500 – 1000 mg a.i./kg sediment dry weight for 28 days,

NOECtotal number of worms/reproduction:  250 mg a.i./kg sediment dry weight

LOECtotal number of worms/reproduction:  500 mg a.i./kg sediment dry weight

 

NOECbiomass:  500 mg a.i./kg sediment dry weight

LOECbiomass:  1000 mg a.i./kg sediment dry weight

Key value for chemical safety assessment

EC50 or LC50 for freshwater sediment:

1 000 mg/kg sediment dw

EC10, LC10 or NOEC for freshwater sediment:

250 mg/kg sediment dw

Additional information

No final results for sediment toxicity are available, however, draft results were used instead. Please note that due to the equivocal results no new risk assessment could be performed. A new rsik assessment including eventually changed exposure scenarios will be added as soon as possible in form of a spontaneous IUCLID update.

 

The effects of the test item on the oligochaete Lumbriculus variegatus in a water-sediment system were determined under static conditions.
The study was carried out according to OECD Guideline 225 (2007). The test duration was 28 days from the insertion of the test organisms. The study was performed by spiking artificial sediment with the test item concentrations 62.5 – 125 – 250 – 500 – 1000 mg a.i./kg sediment dry weight. A control using untreated artificial sediment was set up. Six replicates per control and four replicates per test item concentration were set up for biological investigations.  
Analytical evaluation of the test item PC-2020-932 and the control was carried out via LC-MS/MS for sediment layer, aqueous phase and pore water on day 0, day 7 and day 28 using additional replicates. The measured concentrations of the test item in the sediment were in the range from 104% to 114% at day 0, from 108% to 118% at day 7 and from 107 to 119% of the nominal concentrations at day 28. Minor recoveries of the concentrations of the test item in the aqueous phase and pore water could be determined. The Control samples were < LOQ.

After 28 days of exposure, test item induced no mortality in any test item concentration.
The total number of worms and thus the reproduction did not statistically significantly differ compared to the control in the test item concentrations 62.5 to 250 mg a.i./kg sediment dry weight. However, at the test item concentrations 500 and 1000 mg a.i./kg sediment dry weight the total number of worms was statistically significantly reduced.
Compared to the control, the total biomass per replicate was not statistically significantly different at the test item concentrations 62.5 to 500 mg a.i./kg sediment dry weight. However, at the test item concentration 1000 mg a.i./kg sediment dry weight the total biomass per replicate was statistically significantly reduced.
All validity criteria were fulfilled.

Results Synopsis

 

NOEC_{total number of worms/reproduction}:  250 mg a.i./kg sediment dry weight

LOEC_{total number of worms/reproduction}:  500 mg a.i./kg sediment dry weight

 

NOEC_biomass:  500 mg a.i./kg sediment dry weight

LOEC_biomass:  1000 mg a.i./kg sediment dry weight