Copper hydroxide nitrate (Cu2(OH)3(NO3))

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Substance taken as reference was nano-sized rendering the results very conservative.

Data source

Reference

Reference 1

Reference Type:

secondary source

Title:

Unnamed

Year:

2008

Reference 2

Reference Type:

publication

Title:

Toxicity of nanosized and bulk ZnO, CuO and TiO2 to bacteria Vibrio fischeri and crustaceans Daphnia magna and Thamnocephalus platyurus

Author:

Heinlaan, M., Ivask,A., Blinova, I., Dubourguier H.C. and Kahru, A.

Year:

2008

Bibliographic source:

Chemosphere 71, 1308-1316 (2008)

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Standard operational procedure of Thamnotoxkit FTM (1995)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Copper oxide

EC Number:

215-269-1

EC Name:

Copper oxide

Cas Number:

1317-38-0

Molecular formula:

CuO

IUPAC Name:

copper (II) oxide

Constituent 2

Reference substance name:

CuO

IUPAC Name:

CuO

Details on test material:

Formula: CuO
Nanosized CuO with particle size around 30 nm compared with bulk CuO

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Details on test solutions:

CuO nanosized was purchased from Sigma-Aldrich and bulk CuO from Alfa Aesar. The stock suspensions in Mill-Q (40 g/L) were sonicated for 30 minutes and stored in the dark at 4°C.

Test organisms

Test organisms (species):

other aquatic crustacea: Thamnocephalus platyurus

Details on test organisms:

Test plates with fairy shrimp were incubated for 24h at 25°C in the dark. Tests were performed in triplicate.

Study design

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Test conditions

pH:

7.3 - 7.8

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

400 µg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Copper (nanosized CuO)

Basis for effect:

mortality

Effect concentrations 2

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

1.7 mg/L

Nominal / measured:

estimated

Conc. based on:

element

Remarks:

Copper (nanosized CuO)

Basis for effect:

mortality

Effect concentrations 3

Duration:

24 h

Dose descriptor:

other: LC20

Effect conc.:

1.32 mg/L

Nominal / measured:

estimated

Conc. based on:

element

Remarks:

Copper (nanosized CuO)

Basis for effect:

mortality

Effect concentrations 4

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

20 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

Copper (bulk CuO)

Basis for effect:

mortality

Effect concentrations 5

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

75.6 mg/L

Nominal / measured:

estimated

Conc. based on:

element

Remarks:

Copper (bulk CuO)

Basis for effect:

mortality

Effect concentrations 6

Duration:

24 h

Dose descriptor:

other: LC20

Effect conc.:

49.7 mg/L

Nominal / measured:

estimated

Conc. based on:

element

Remarks:

Copper (bulk CuO)

Basis for effect:

mortality

Details on results:

Free ionic copper is considered the active ingredient in inorganic copper salts, and is believed to be repsonsible for adverse effects. The bioavailablity of the copper ion at target sites determines the severity of effects. Both copper oxide and and copper hydroxide nitrate are considered sparingly soluble inorganic copper salts and would be expected to dissociate similarly within the organism. As test material is in nano form, results are considered to be very conservative.
LC50 values for nano CuO were about 50-fold lower than for its bulk form to D. magna and T. platyurus. The NOEC values (both crustacean
assays) for nano CuO were 50–100-fold lower than for bulk CuO. When response to nano and bulk CuO was expressed as a function of bioavailable Cu (calculated), the toxicity of both nano and bulk CuO was almost identical to that of free Cu2+ (CuSO4) for T. platyurus but not for D. magna.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the test, the NOEL for nano-sized Copper oxide, using a fairy shrimp, was 400 µg Cu/L and was taken as reference. Based on a content of 53% Copper in Basic Copper Nitrate, the invertebrates NOEL for this substance is estimated to be 755 µg/L.