Cobalt carbonate

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

other information

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline, analytical monitoring. Carefully performed, well documented study.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Toxicity of cobalt and copper to rainbow trout: application of a mechanistic model for predicting survival.

Author:

Marr JCA et al.

Year:

1998

Bibliographic source:

Aquatic Toxicology 43(4):225–238.

Reference 2

Reference Type:

secondary source

Title:

CICAD 69, Cobalt and inorganic cobalt compounds

Author:

WHO

Year:

2006

Materials and methods

Principles of method if other than guideline:

Flow through test, analytical monitoring, fry stage, soft water

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Cobalt dichloride dihydrate

IUPAC Name:

Cobalt dichloride dihydrate

Constituent 2

Reference substance name:

Nitric acid, cobalt salt

EC Number:

238-075-9

EC Name:

Nitric acid, cobalt salt

Cas Number:

14216-74-1

Details on test material:

- Analytical purity: reagent grade

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Metal exposures were controlled by metering stock solutions via Mariotte bottles into the dilution box of a continuous-flow, proportional
diluter. The stock solutions were prepared from reagent grade metal Salts (CoCI2 * 2H2O and CuCI * 6H2O) dissolved in deionized water and stored in acid washed 200-L Nalgene polypropylene containers. Proportional diluters delivered exposure and control waters to each aquarium (8 L water volume) at 0.2 L min-1of water, providing a flow rate of 288 L day-1 (36 volume renewals day-1).

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: obtained from a local hatchery (Dubois Fish Hatchery, Wyoming Game and Fish Department)
- Age at study initiation (mean and range, SD): 14 days
- Length at study initiation (length definition, mean, range and SD): 29-32 mm
- Feeding during test: no

ACCLIMATION
- Acclimation period: 14 days
- Acclimation conditions (same as test or not): yes
- Health during acclimation (any mortality observed): no
Eggs were hatched at the laboratory in incubators using well water (hardness 220 mg L-1 as CaCO3; alkalinity 180- 210 mg L-1 as CaCO3; pH 7.2-7.8; temperature 7°C). After hatching, trout were transferred to circular holding tanks and acclimated for more than 14 days to the control water used in the bioassay (hardness 25-30 mg L- 1 as CaCO3; alkalinity 22-28 mg L- 1 as CaCO3; pH 7.3-7.6; temperature 10°C). Fish condition and health were monitored daily, and fish remained disease-free. Cultures and experimental animals were kept on a 12-h light/dark cycle.
- Type and amount of food/Feeding frequency: At swim-up, trout were fed frozen BioDiet once daily at a ration in excess of 4.5% (wet wt, food/ wet wt. body weight). Fish were deprived of food 48 h before and throughout experimentation.

Study design

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

14 d

Test conditions

Hardness:

24.9±0.7 mg/L CaCO3

Test temperature:

9.9±0.3 °C

pH:

7.51±0.11

Dissolved oxygen:

8.5±0.2 mg/L

Nominal and measured concentrations:

0-2.5 mg/L Co

Details on test conditions:

TEST SYSTEM
- Test vessel: Aquaria
- Type (delete if not applicable): open
- Type of flow-through (e.g. peristaltic or proportional diluter): proportional
- Renewal rate of test solution (frequency/flow rate): 0.2 L min-1 (36 volume renewals per day)
- Biomass loading rate: < 1.5 g/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Waters were formulated by continuously mixing well water and deionized water (well water treated with sediment filtration, reverse osmosis, and separate-bed deionization) to attain the following nominal water quality conditions: hardness 25 mg L-1 as CaCO3; alkalinity 25 mg L-1 as CaCO3; pH 7.5; temperature 10°C.
- Chlorine: 1.4 mg/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: daily


OTHER TEST CONDITIONS
- Adjustment of pH: yes, automatically
- Photoperiod: 12:12 L:D


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Exposure and control waters were sampled daily from randomly determined replicates for pH, alkalinity, hardness, dissolved oxygen, and temperature. Water samples were collected every three days from randomly determined replicates for analysis of major cations, major anions, and metals (Co, Cu).

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.4 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Co

Basis for effect:

mortality (fish)

Effect concentrations 2

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

0.52 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Co

Basis for effect:

mortality (fish)

Any other information on results incl. tables

Sublethal observations / clinical signs:

Mean measured Co and Cu concentrations were approximately 85-119%, of the nominal concentrations. For all experiments, the water quality conditions, major cations and anions, and metals were constant throughout the exposure period.

The mean cumulative control mortality (0 µg/L exposure to Co or Cu) in all tests was < 5% at 96 h and < 8% at 168 h; mortality then increased over time because of starvation (>10%).

Co-induced lethality did not occur prior to 72 h of exposure, with the majority of toxicity observed between 72 and 192 h. These results emphasize that standard short term 96-h acute toxicity tests with rainbow trout will underpredict Co toxicity substantially.