Copper cyanide

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008-03-17 to 2008-04-18

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

April 13, 2004

Deviations:

no

Principles of method if other than guideline:

N/A

GLP compliance:

yes

Specific details on test material used for the study:

See test material information above

Analytical monitoring:

yes

Details on sampling:

Test concentrations were verified by chemical analysis. Water samples were taken from the controls and each exposure level at the start (0 h) and at te end (48 h) of the test for analysis.
10 mL (x 3 replicates) of test solution was taken from the each test vessel prepared at the beginning of the test. At the end of the test, each 10 mL of test solution was taken from 4 replicates vessels for each test concentration and then pool. pooled solution was divided into triplicate samples in 20 mL of vials. 0.3 mL of nitric acid solution (61%) was added into the samples and then the samples were sent to the chemical analysis laboratory at KOREA Research Institute of Chemical Technology for analysis of copper.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
After 201 mg of the test substance was added in 2 000 mL eaker and dilution water was added up to the mark of the beaker to produce the nominal concentration of 100 mg/L, this solution was then stirred for about 48h. Serial dilutions of this test solution were prepared with the dilution water to give desired series of exposure levels which were nominally 25, 12.5, 6.25, 3.13, 1.56, and 0.78 mg/L. For the control group, only the dilution water was used.

No remarkable phenomenon was observed in the test solution.

Test organisms (species):

Daphnia magna

Details on test organisms:

SOURCE
Daphnids culture-room in the Division of Non-clinical Studies, Korea Institute of Toxicology (KIT), Korea Research Institute of Chemical Technology (KRICT), Daejon, Korea, originally purchased from the Carolina Science & Math, USA.

CULTURE
Brood stock of Daphniamagna were cultured under 16h light : 8h dark at 18-22°C in glass beakers containing three liters of M4 medium. Cultures were fed daily with a suspension of algae (chlorella sp.) and the amount of the supplied algae was range of 0.1 - 0.2 mg carbon/animal/day. Culture conditions ensured that reproduction was by parthenogenesis.
Gravid adults were isolated 24h prior to initiation of the test. Young daphnids produced overnight (< 24 h old) were used for testing.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

None

Post exposure observation period:

No data

Hardness:

240 mg/L

Test temperature:

20.1 +/- 0.5°C

pH:

7.96 - 8.10

Dissolved oxygen:

8.1 - 8.9 mg/L

Salinity:

No data

Conductivity:

No data

Nominal and measured concentrations:

Nominal: control, 0.78; 1.56; 3.13; 6.25; 12.5 and 25 mg/L
Mean measured concentrations: 0.03; 0.06; 0.15; 0.31; 0.61 and 1.23 mg/L

Details on test conditions:

CULTURING AND DILUTION WATER
M4 Medium was used as culturing and dilution water and was prepared according to the OECD guideline.
It had a total hardness and alkalinity (as CaCO3) of 240 mg/L and 40.4 mg/L (date of analysis: April 4, 2008) respectively.

MEDIUM RENEWAL
This test substance was stable in the test solution for 48h. therefore, the definitive test was carried out without renewal of the test solution.

ENVIRONMENTAL CONDITIONS
Dissolved oxygen and pH were recorded at the start and at the end of the study for all treatments. water temperature was recorded daily in control. the water temperature, dissolved oxygen (DO) and pH during the exposure period were maintained as follows:
- T°C: 20.1 +/- 0.5°C
- DO: 8.1 - 8.9 mg/L (89-98% of ASV)
- pH: 7.96 - 8.10

The photoperiod was 16h light and 8 h dark, including 30 min dawn and dusk transition periods. The light intensity was measured prior t the test and at the end of the test, and ranged from 707 to 789 lux.
No food nor air was provided during the test period.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Daphnia was examined daily for symptoms of intoxication and immobilization. The animals were considered to be immobilized if they were unable to swim for approximately 15 seconds after gentle agitation.

EXPERIMENTAL DESIGN
Five first instar Daphnia were random in each crystallizing dish containing 100 mL of prepared test solution. Total number of organisms per each test concentration was twenty daphnids (4 replicates per test concentration). The dishes were loosely covered with glass cover to minimize evaporation losses.

RANGE-FINDING STUDY
- 100% immobilization at 100 mg/L (nominal) and 60% at 10 mg/L (nominal)
- Results used to determine the conditions for the definitive study: Therefore, the definitive test was conducted in the concentrations between 1-100 mg/L of nominal concentrations.

Reference substance (positive control):

not specified

Remarks:

No data

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

0.45 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL [0.42 - 0.49 mg/L]

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.21 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL [0.17 - 0.26 mg/L]

Duration:

24 h

Dose descriptor:

LOEC

Effect conc.:

0.61 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

0.15 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

0.31 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.06 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

ANALYTICAL RESULTS
- Method validation: See the analytical report in the attached document
- Stability of test substance: The measured concentration of 100 mg/L (nominal concentration) of test solution was 4.78 mg/L (4.78% of nominal concentration) at 0h. The concentrations were 4.77 - 4.88 mg/L during 48h abd they were 99.8 - 102.1% of initial concentrations.
- Analaysis of test substance: the concentrations of the test substance measured were from 3.85 to 5.44% of the nominal concentrations. Therefore, the results of the study will be expressed based on the mean measured concentrations (geo mean).

BIOLOGICAL RESULTS
There were no immobilizations or adverse effects observed in any of the daphnids exposed to control during test period. however, exposure of daphnids to nominal concentrations or 3.13, 6.25, 12.5, and 25 mg/L (mean measured concentrations: 0.15, 0.31, 0.61, and 1.23 mg/L) resulted in 25, 75, 100 and 100% immobility, respectively.
All results were expressed in terms of mean measured concentrations (geometric mean).

Results with reference substance (positive control):

No data

Reported statistics and error estimates:

No data

See tables in the chapter 7 of the study report attached

Validity criteria fulfilled:

not specified

Conclusions:

Under the test conditions, the test item copper cyanide exhibits a 48h-EC50 of 0.21 mg/L [95% CL 0.17-0.26 mg/L], based on mean measured concentrations.

Executive summary:

The study was conducted to assess the acute toxicity of copper cyanide to Daphnia magna under static system.

The study was conducted in accordance with the OECD 202 guideline and under GLP conditions. Based on a range-finding study, the definitive test was performed based on the following nominal concentrations: 0.78, 1.56, 3.13, 6.25, 12.5 and 25 mg/L. Twenty daphnids (less than 24 hours old), divided into 4 groups of five, were exposed to each treatment concentration and control.

Based on chemical analyses, the stability of the test item during the test period was demonstrated and the mean measured concentrations at 48h were 0.00.04, 0.07, 0.17, 0.34, 0.66 and 1.32 mg/L, corresponding to 4.49-5.44% of the nominal values). Therefore, all results were based on mean measured concentrations (geometric means).

Observations were made on the incidence of immobilization after 24, and 48 hours of exposure. Under the test conditions, the test item copper cyanide exhibits a 48h-EC50 of 0.21 mg/L [95% CL 0.17-0.26 mg/L], based on mean measured concentrations.

Description of key information

Under the test conditions, the test item copper cyanide exhibits a 48h-EC50 of 0.21 mg/L [95% CL 0.17-0.26 mg/L], based on mean measured concentrations.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.21 mg/L