Copper, diammine[5,5'-bi-1H-tetrazolato(2-)-kN1, kN1']

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

The water temperature dropped below 21°C (20.8°C), minimum recommended temperature, for a few hours (period corresponds to the extinction of the light), the second and third day of incubation.

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate is included in the report

Analytical monitoring:

yes

Details on sampling:

Analyses were performed for the definitive test on controls and test solutions at T0, T24h, T48h (before and after renewal of test solutions), T72h and T96h

Vehicle:

no

Details on test solutions:

Available information has shown that the test item is not soluble in water.
A stock solution was prepared in the dilution water (nominal concentration: 500.0 mg/L), in the dark under magnetic stirring, one week before initiating the fish acute toxicity test.After membrane filtration (nylon membrane filter, 0.45 µm pore size, 90 mm diameter), the stock solution was diluted in the dilution water to achieve the required test concentrations. Most of the copper was undissolved and was removed by filtration.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

Zebrafish Danio rerio (Hamilton,1822-Teleostei, Cyprinidae) obtained from a single stock held in test facility since November 23rd 2016.Supplier: EXOMARC (33310 Lormont, FRANCE)Holding:- Water: Dilution water NF EN ISO 6341 (continuous aeration and filtering device)- Feeding: TetraMin Tetra- Light: 14-hour light / 10-hour dark cycleBatch of fish used during the definitive test:Mean size: 2.8 cm ± 0.2 cmMean wet weight: 0.40 g ± 0.07 gNo mortality for the batch of fish before the start of the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Remarks on exposure duration:

Renewal of controls and test solutions after 48 hours

Hardness:

Not available

Test temperature:

Between 20.8 and 21.7°C

pH:

Controls: between 7.1 and 7.9
Test solutions: between 7.2 and 8.7

Dissolved oxygen:

Controls: between 5.9 and 8.9Test solutions: between 3.4 and 8.7

Salinity:

Not available

Conductivity:

of dilution water (reconstituted water - NF EN ISO 6341): 635 µS/cm

Nominal and measured concentrations:

64.2 – 96.3 – 144.4 – 216.7 and 325.0 mg/L (initial nominal concentrations)

Details on test conditions:

Vessel: 5 litres glass vessels filled with 4 litresTest: 2 blank controls + 2 test vessels by concentrationNumber of animals: 8 for test concentrations and 8 for the controlsTest concentrations:Limit test: 326.5 mg/L (initial nominal concentration)Definitive test: 64.2 – 96.3 – 144.4 – 216.7 and 325.0 mg/L (initial nominal concentration)Biomass: 0.4 g/LFeeding: noneLight: 14-hour light / 10-hour dark cycleTemperature: between 20.8 and 21.7°C in a temperature-controlled roomAeration: noneRenewal: after 48 hours (test concentrations and controls)Duration: 96 hoursTimes of observation: 2 - 5 - 24 – 48 – 53 - 72 - 96 hoursToxic effect: Fish are considered dead if there is no visible movement (e.g. gill movements) and if touching of the caudal peduncle produces no reaction.

Reference substance (positive control):

yes

Remarks:

K2Cr2O7

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

216.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other:

Remarks:

(initial nominal concentrations) corresponding to an exposure to a mixture of 5.4 µg/L dissolved copper and 78 mg/L 5,5’-bi-1H-tetrazole (diammonium salt).

Details on results:

The analyses performed during this study therefore confirmed that a certain amount of the test item is solubilized in the test medium after one week under magnetic stirring.

Results with reference substance (positive control):

Test result for the selected batch (test carried out from 11 January 2017 to 12 January 2017): LC50 24h = 191.7 mg/L (187.9 – 196.3)The LC50 24 hours was calculated using a logistic regression analysis with a bootstrap estimation of the 95% confidence limits.This value is included in the warning limits of the laboratory (mean LC50  2 SD) on this species corresponding to two standard deviations from the historic geometric mean of the median lethal concentration (141.6 – 259.7 mg/L). This result confirmed the appropriate sensitivity of the fish batch.

Sublethal observations / clinical signs:

Limit test carried out on January 23, 2017

Exposure time	Controls		CuDABT 326.5 mg/L (nominal concentration (mg/L))
Test vessel	1	2	1	2
4h	0	0	4	4
Mortality after 4h (%)	0	0	100	100
pH	ND	ND	8.6	8.6
Dissolved oxygen (mg/L)	ND	ND	8.6	8.5

Definitive test:

Mortality observed within the test period:

Exposure time	Controls		CuDABT (nominal concentration (mg/L))
			64.2		96.3		144.4		216.7		325.0
2 h	0	0	0	0	0	0	0	0	0	0	4	4
5 h	0	0	0	0	0	0	0	0	1	0	/	/
24 h	0	0	0	0	0	0	0	0	2	1	/	/
48 h	0	0	0	0	0	0	0	0	2	1	/	/
53 h	0	0	0	0	0	0	0	0	2	2	/	/
72 h	0	0	0	0	0	0	0	0	2	2	/	/
96 h	0	0	0	0	0	0	0	0	2	2	/	/
Mortality after 96h (%)	0		0		0		0		50.0		100

pH measurements:

Exposure time	Controls		CuDABT (nominal concentration (mg/L))
			64.2		96.3		144.4		216.7		325.0
0	7.9	7.9	8.5	8.5	8.6	8.6	8.6	8.6	8.7	8.7	8.7	8.7
24 h	7.2	7.2	7.5	7.5	7.7	7.7	8.0	8.0	8.3	8.3	8.6	8.6
48 h	7.2	7.2	7.3	7.3	7.3	7.3	7.6	7.6	8.2	8.0	/	/
48 h (New test solution)	7.8	7.8	8.5	8.5	8.6	8.6	8.6	8.6	8.7	8.7	/	/
72 h	7.2	7.2	7.8	7.7	7.9	8.0	8.2	8.2	8.5	8.4	/	/
96 h	7.1	7.1	7.2	7.2	7.3	7.2	7.2	7.2	8.1	7.7	/	/

Dissolved oxygen measurements (mg/L):

Exposure time	Controls		CuDABT (nominal concentration (mg/L))
			64.2		96.3		144.4		216.7		325.0
0	8.9	8.9	8.8	8.8	8.8	8.8	8.8	8.8	8.7	8.8	8.7	8.7
24 h	6.3	6.2	6.2	6.2	6.2	6.0	6.1	6.2	7.1	6.7	8.5	8.5
48 h	5.9	6.0	5.8	5.8	5.9	5.5	5.8	5.7	6.9	6.3	/	/
48 h (New test solution)	8.9	8.9	8.9	8.9	8.9	8.9	8.8	8.8	8.8	8.8	/	/
72 h	6.8	6.8	6.8	6.7	6.6	5.7	6.2	6.1	7.3	7.1	/	/
96 h	6.1	6.2	5.5	5.6	5.5	4.0	3.4	3.7	5.4	4.8	/	/

Validity criteria fulfilled:

yes

Remarks:

The mortality observed in control vessels did not exceed 10% at end of the test. The dissolved oxygen concentration was at least 60% of air saturation value in control vessels throughout the test period. For other criteria see chapter "Overall remarks"

Conclusions:

In the test conditions, 50% fish mortality was observed after 96 hours of exposure to the concentration of CuDABT of 216.7 mg/L (initial nominal concentration).

Executive summary:

In order to determine acute toxicity, the fish are exposed to the test item: CuDABT during a period of 96 hours.

Mortality is recorded at 24, 48, 72 and 96 hours.

Available information has shown that the test item is not soluble / poorly soluble in water and satured solution has been used. In the test conditions, 50% fish mortality was observed after 96 hours of exposure to the concentration of CuDABT of 216.7 mg/L (initial nominal concentration).

Description of key information

In the test conditions, 50% fish mortality was observed after 96 hours of exposure to the concentration of CuDABT of 216.7 mg/L (initial nominal concentration).

The LC50 is determined as 216.7 mg/L.

LC50 > 100 mg/L (nominal concentration of CuDABT)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

216.7 mg/L