Reaction mass of copper oxide and manganese dioxide

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

For details on endpoint specific justification please see read-across report in section 13 or find a link in cross-reference “read-across: supporting information”.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.04 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

element (dissolved fraction)

Remarks:

copper

Basis for effect:

mortality (fish)

Remarks on result:

other: dissolved metal fraction corresponding to nominal 4444 mg/L submission substance, dissolved Cu measured after 2 days

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 4 444 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mortality (fish)

Remarks on result:

other: value recalculated based on the ratio of MnO2 and CuO in the reaction mass

Validity criteria fulfilled:

yes

Conclusions:

The 96h-LC50 (Cyprinus carpio) was > 4444 mg/L (nominal); corresponding to 0.04 mg/L dissolved copper, measured after 2 days; 96h-LC20 ca. 4444 mg/L.

Executive summary:

The study investigated the distribution of CuO nanoparticles in juvenile carp (Cyprinus carpio) and the potential toxicity (acute and sub-acute). Next to CuO nanoparticles, all tests were performed with CuO bulk material. The determination of the lethal concentration (LC50) measured during 96 hours followed the principles of OECD TG 203. The study results of the source compound were considered applicable to the target compound and were used for classification and labelling acc. to REGULATION (EC) No 1272/2008. Justification and applicability of the read-across approach (structural analogue) is outlined in the attached document (see section 13 or find a link in cross reference).

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

For details on endpoint specific justification please see read-across report in section 13 or find a link in cross-reference “assessment report”.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

assessment report

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 143 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mortality (fish)

Remarks on result:

other: value recalculated based on the ratio of MnO2 and CuO in the reaction mass

Validity criteria fulfilled:

yes

Conclusions:

The derived 96h-LC50 (rainbow trout) > 143 mg/L (limit test, 100% (v/v) saturated solution prepared at 100 mg/L test item); no toxic effects were observed.

Executive summary:

The study used as source investigated the acute toxicity to fish acc. to OECD 203. The study results of the source compound were considered applicable to the target compound and were used for classification and labelling acc. to REGULATION (EC) No 1272/2008. Justification and applicability of the read-across approach (structural analogue) is outlined in the read-across report in section 13 or find a link in cross reference “assessment report”.

Description of key information

96h-LC50 (Rainbow trout) > 143 mg/L (limit test, 100% (v/v) saturated solution prepared at 100 mg/L, nominal, OECD 203)

Additional information

Two reliable key studies were available for the hazard assessment of acute toxicity to fish for the submission substance reaction mass of copper oxide and manganese dioxide.

Acute toxicity of the constituent manganese dioxide to fish was investigated in a study, which was conducted under GLP conditions and in accordance with OECD 203 and EU Method C.1 (RL1, 2010). As the test material was considered to be of very low water solubility, a limit test was performed with a saturated solution prepared at 100 mg/L test material (100 % (v/v) saturated solution prepared at 100 mg/L). Two fish were observed dead in one replicate after 72 hours exposure. Given that no other mortalities were observed, and no sub-lethal effects were observed throughout the duration of the test, these mortalities were related to natural causes rather than a toxic effect of the test material. There were no sub-lethal effects of exposure observed in 14 fish exposed to a test concentration of 100% (v/v) saturated solution for a period of 96 hours. The 96-hour LC50 value was therefore considered to be > 143 mg/L (value recalculated based on the ratio of MnO2 and CuO in the reaction mass). Therefore, no toxic effects were observed up to the limit of water solubility of the test item.

The second key study investigated the acute toxicity of constituent copper oxide to fish during 96 hours and followed the principles of OECD 203 (RL 2, 2011). Eight nominal test concentrations were tested. Each concentration was run in triplicates. The dissolved copper fraction of each test concentration was determined in a parallel experiment. Fish mortality was observed in concentrations >= 1333 mg/L (value recalculated based on the ratio of MnO2 and CuO in the reaction mass). Mortality occurred in a dose-related manner, i.e. increasing number of dead fish with increasing concentrations. At the highest test concentration of 4444 mg/L (value recalculated based on the ratio of MnO2 and CuO in the reaction mass), mortality was not greater than 20%. The derived 96h-LC50 was > 4444 mg/L (nominal, corresponding to 0.04 mg/L dissolved copper measured after two days). With regard to observed sub-lethal effects, measured tail beat frequency of carp was lower for exposed fish compared to the control (no clear dose-response pattern).

Despite of shortcoming in reporting, results of the study were considered reliable. The applied test concentrations covered a wide range of concentrations (including the limit concentration of 100 mg/L acc. to OECD 203). The derived lethal effect concentrations were considered adequate to evaluate adverse effects of the submission substance in fish.

As the constituents did not cause mortality of > 50% in fish up to a nominal concentration of 100 mg/L (saturated solution), the reaction mass of copper oxide and manganese dioxide were considered non-hazardous for fish during short-term exposure.