Cesium formate

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:

From April 22, 2003 to May 2, 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

A) Test methods were conducted in accordance with SOP 102, which conforms to the Paris Commission guidelines for conducting sediment toxicity tests with the amphipod Corophium volutator (OSPARCOM, 1995). GLP practices have also been observed in the study. B) Well-defined information were provided on: 1. Test system (test species, source, test vessels, test and stock solutions, test conditions and composition) 2. Compositional information of the test substance and controls used. 3. Test procedure (treatment groups, controls) 4. Detailed test results and observations 5. Calculation of LC50 and LC90 and NOEC values for each sampling time.

Qualifier:

according to guideline

Guideline:

other: Paris Commission guidelines for conducting sediment toxicity tests with the amphipod Corophium volutator (OSPARCOM, 1995)

Deviations:

yes

Remarks:

The pH exceeded the upper limit by up to 0.19 pH units in the 10000 mg/kg test concentration on day10.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Details on sampling:

Sampling of test water done on Days 0, 3, 6, 8 and 10. Dissolved oxygen, pH, conductivity and temperature were measured on Days 0, 3, 6 and 10. Conductivity measurement was additionally done on Day 8.

Vehicle:

yes

Test organisms (species):

Corophium volutator

Details on test organisms:

TEST ORGANISM
- Common name: No data
- Strain/clone: No data
- Justification for species other than prescribed by test guideline: Not applicable
- Source: Bay of Suckquoy, near Sebay farm in Orkney
- Details on collection: Specimens were collected by gentle sieving from their natural sediment, held in 5 L plastic containers with some ambient water and detritus. They were transferred to gently aerated ambient water at 10.5 ˚C in 200 L polythene tanks in temperature controlled room in the laboratory.
- Age of parental stock (mean and range, SD): No data
- Breeding conditions: No breeding after collection
- Handling of egg masses and larvae: No data
- Age of animals at beginning of exposure: Age not specified, length - 5 mm (excluding rostrum) at study initiation
- Feeding during test
- Food type: No feeding during test
- Amount: Notapplicable
- Frequency: Not applicable

ACCLIMATION
- Acclimation period: 6 d
- Acclimation conditions (same as test or not): Animals were gradually acclimated from the ambient salinity of 2 % to that of undiluted seawater (approximately 35 %) in increments of approximately 10 % per day. On completion of the acclimation, the stock animals were maintained under semi-static conditions till initiation of study.
- Type and amount of food:Detrital material, ad libitum
- Feeding frequency: No data
- Health during acclimation (any mortality observed): No mortality observed

Study type:

laboratory study

Test type:

static

Water media type:

saltwater

Type of sediment:

natural sediment

Limit test:

yes

Duration:

10 d

Exposure phase:

total exposure duration

Post exposure observation period:

No

Hardness:

No data

Test temperature:

14.0-15.7 ˚C

pH:

8.02-8.69

Dissolved oxygen:

95-101 mg O2/L

Salinity:

No data

Ammonia:

No data

Nominal and measured concentrations:

Target wet weight nominal conc. (mg/kg): 10, 100, 320, 1,000 and 10,000
Nominal wet weight conc. (mg/kg): 13.29, 131.44, 420.82, 1,316.00 and 13,150.93

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 1 L
- Sediment volume:1 L capacity glass beakers containing 2 cm depth (approximately 150 mL) of amended sediment and 850 mL of overlying seawater (I µm filtered ultra violet treated seawater)
- Weight of wet sediment with and without pore water:
- Overlying water volume: 850 mL
- Depth of sediment and overlying water: Sediment depth - 2 cm
- Aeration: Yes
- Aeration frequency and intensity: Aeration was provided and a stream of air bubbles were released at a depth of approximately 6 cm, frequency not reported
- Replacement of evaporated test water, if any: No data

EXPOSURE REGIME
- No. of organisms per container (treatment): 60 animals per concentration, 100 animals in five vessels for controls
- No. of replicates per treatment group: Three replicates
- No. of replicates per control / vehicle control: Five replicates
- Feeding regime: No feeding
- Type and preparation of food: Not applicable
- Amount of food: Not applicable

RENEWAL OF OVERLYING WATER
- Details on volume additions: No data
- Flow-rate: No data

OVERLYING WATER CHARACTERISTCS
- Type of water (e.g. deionized, ground water, sea water, Elendt medium acc. to OECD 219): Sea water
- Source of water (if non-standard medium)
- Location: Seawater for testing was supplied by pump from Scapa Flow, Orkney
- Description of sampling site: No data
- Filtration: All seawater is UV sterilised and filtered to 1 µm before being employed for testing.

SOURCE OF NATURAL SEDIMENT
- Location and description of sampling site: Collected from a point adjacent to the site of Corophium collection (Bay of Suckquoy)
- Contamination history of site: No data

HANDLING OF NATURAL SEDIMENT- The sediment was wet-sieved through a 0.6 mm mesh to remove larger infaunal organisms and Corophium within the test size range, and allowed to settle in a polyethylene container. After settling, the supernatant water was decanted and the sediment stored at 4±2 ˚C, until required for testing.
- Time of collection: No data
- Core depth: No data
- Water depth: No data
- Storage conditions: Stored at 4±2 ˚C until used for testing
- Storage duration (prior to test): No data

CHARACTERIZATION OF (ARTIFICIAL; delete if not applicable) SEDIMENT
- % dry weight of sphagnum moss peat: No data
- Particle size distribution - Median particle diameter was 151 µm
- % sand: Fine sand
- % silt: silt/clay content of 3.56 % by weight
- % clay: silt/clay content of 3.56 % by weight

- Sediment sieved: yes, mesh size - 0.6 mm
- Total organic carbon (%): Total organic material as determined from weight loss on ignition was 1.34%.

OTHER TEST CONDITIONS
- Light quality: No data
- Photoperiod: Constant dim illumination
- Light intensity: Dim

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality, observed after 10 d

VEHICLE CONTROL PERFORMED: Yes

TEST CONCENTRATIONS
- Spacing factor for test concentrations: ~ 10
- Justification for using less concentrations than requested by guideline: No data
- Range finding study
- Test concentrations: No range finding study reported
- Results used to determine the conditions for the definitive study: Not applicable

Reference substance (positive control):

no

Key result

Duration:

10 d

Dose descriptor:

other: LC90

Effect conc.:

ca. 11 851.3 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Key result

Duration:

10 d

Dose descriptor:

LC50

Effect conc.:

ca. 6 652.88 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: 7675.89 mg/kg - 5227.98 mg/kg

Key result

Duration:

10 d

Dose descriptor:

NOEC

Effect conc.:

ca. 1 316 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Details on results:

- Mortality of test animals at end of exposure period: Dose dependent mortality observed from 13.29 mg/kg, 100 % mortality observed at the highest dose of 13150.93 mg/kg
- Other biological observations: No visible signs of animals on the sediment surface whether alive or dead were recorded

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

No details available

Mortality observed in control after 10 d

Vessels	Number of animals per  vessel	Mortality	Mortality per vessel	Raw mean
1	20	0.05	1	0.03 (3 %)
2	20	0.00	0
3	20	0.05	1
4	20	0.05	1
5	20	0.00	0

Mortality observed in test concentrations after 10 d

Treatment mg/kg dry weight	Number of animals per concentration	Mortality	Raw mean (proportional response)
13.29	60	2	0.03
131.44	60	3	0.05
420.82	60	3	0.05
1,316.00	60	7	0.12
13,150.93	60	60	1.00

Test water chemistry:

Wet wt conc. Rep	Day 0			Day 3			Day 8			Day 10
	DO	pH	T	DO	pH	T	DO	pH	T	DO	pH	T
10	97- 98	8.05	14.8- 14.9	96-97	8.02	14.0	95- 96	8.11	15.3	101 - 99	8.16 -8.14	14.7 - 14.6
100	97- 98	8.07	14.8- 14.9	96	8.02	14.0- 14.1	97- 96	8.09 - 8.12	15.3 - 15.4	99 - 99	8.16	14.7 - 14.6
320	97- 98	8.07	14.9	96	8.06	14.1- 14.2	97	8.12	15.4 - 15.5	99 - 100	8.15 - 8.19	14.7
1,000	97- 98	8.09	14.9- 15.0	96-97	8.12- 8.13	14.2	97- 96	8.23 - 8.25	15.5 - 15.6	99 - 100	8.26- 8.32	14.7
10,000	97- 98	8.07 - 8.09	14.9	96-97	8.20- 8.21	14.3	95- 97	8.52 - 8.52	15.6 - 15.7	99 - 101	8.65 - 8.69	14.8

Validity criteria fulfilled:

yes

Remarks:

1. Dissolved oxygen range - 95-101 % (more than 85 %). 2. pH range, 8.02-8.65, was approx. within prescribed limit (7.5-8.5). 3. Temperature range, 14.0-15.7, was within the limit (13-17 degree Celsius). 4. Control mortality, 3 %, was within 15 %.

Conclusions:

Under the study conditions the nominal 10 d LC50 and LC90 were 6,652.88 and 11,851.3 mg/kg respectively and the NOEC was determined to be 1,316 mg/kg.

Executive summary:

A study was conducted to determine the acute toxicity of the test substance to the marine amphipod Corophium volutator. The procedure was performed in accordance with SOP 102, which conforms to the Paris Commission guidelines for conducting sediment toxicity tests with the amphipod Corophium volutator (OSPARCOM, 1995). Amphipods were exposed for 10 days to test medium in 1 L capacity glass jar containing 2 cm depth (approximately 150 mL) of amended sediment and 850 mL of overlying seawater. The test substance concentrations were equivalent to 0, 13.29, 131.44, 420.82, 1,316.00, 13,150.93 mg/kg dry weight. No analytical dose verification was conducted. During the test animals were monitored for mortality. Under the study conditions, the nominal 10 d LC50 and LC90 were 6,652.88 and 11,851.3 mg/kg respectively and the NOEC was determined to be 1,316 mg/kg (Hudson, 2003).

Key value for chemical safety assessment

EC50 or LC50 for marine water sediment:

6 652.88 mg/kg sediment dw

EC10, LC10 or NOEC for marine water sediment:

1 316 mg/kg sediment dw

Additional information

A study was conducted to determine the acute toxicity of the test substance to the marine amphipod Corophium volutator. The procedure was performed in accordance with SOP 102, which conforms to the Paris Commission guidelines for conducting sediment toxicity tests with the amphipod Corophium volutator (OSPARCOM, 1995). Amphipods were exposed for 10 days to test medium in 1 L capacity glass jar containing 2 cm depth (approximately 150 mL) of amended sediment and 850 mL of overlying seawater. The test substance concentrations were equivalent to 0, 13.29, 131.44, 420.82, 1,316.00, 13,150.93 mg/kg dry weight. No analytical dose verification was conducted. During the test animals were monitored for mortality. Under the study conditions, the nominal 10 d LC50 and LC90 were 6,652.88 and 11,851.3 mg/kg respectively and the NOEC was determined to be 1,316 mg/kg (Hudson, 2003).