Reaction mass of copper oxide and manganese dioxide

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

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:

assessment report

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

ca. 0.3 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element (dissolved fraction)

Remarks:

copper

Basis for effect:

mobility

Remarks on result:

other: measured dissolved copper concentration was ca. 0.3 mg/L; equal result obtained based on dissolved copper fraction of 0.18% for nominal CuO concentration at pH 7-8 (see section 6.1.5, Aruoja et al. 2009)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

732 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Remarks on result:

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

Validity criteria fulfilled:

not specified

Remarks:

details not given in the publication

Conclusions:

The determined 48h-EC50 (Daphnia magna, immobility) was 732 mg/L (nominal), corresponding to 0.3 mg/L dissolved copper (measured).

Executive summary:

The study used as source reference investigated the toxicity of nano-sized and bulk metal oxides ZnO, CuO and TiO2 to bacteria Vibrio fischeri and crustaceans Daphnia magna and Thamnocephalus platyurus. The bulk form of each metal oxide was used to compare toxic effects between nano and bulk form. The study results of the source compound were considered applicable for 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 aquatic invertebrates

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:

48 h

Dose descriptor:

EC50

Effect conc.:

> 143 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

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 48h-EC50 (Daphnia magna, mobility) > 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 short-term toxicity to aquatic invertebrates acc. to OECD 202. 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

48h-EC50 (Daphnia magna, immobilisation) = 732 mg/L (nominal, total fraction, submission substance), corresponding to 0.3 mg/L dissolved copper (measured) (OECD 202)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.3 mg/L

Additional information

Two reliable key studies were available for the hazard assessment of short-term toxicity to aquatic invertebrates for the submission substance reaction mass of copper oxide and manganese dioxide.

 

One of the key studies investigated the short-term toxicity of manganese dioxide to aquatic invertebrates, conducted under GLP conditions and in accordance with OECD 202 and EU Method C.2. As the test material was considered to be of very low water solubility, the study was conducted with a saturated solution of test material. No daphnia immobilisation was observed over the 48-hour test period. The 48-hour EC50 was therefore determined to be greater than 100% (v/v) saturated solution. The study showed that there were no toxic effects at the limit of solubility of the test material in the test medium. The derived 48h-EC50 for the submission substance was > 143 mg/L (recalculated based on the ratio of MnO2 and CuO in the reaction mass).

The second key study investigated the acute toxicity of copper oxide to Daphnia magna (RL2, 2008). The study was carried out using DAPHTOXKIT F™ according to OECD 202. The study was conducted with five test concentrations, a blank control and positive control (copper sulfate) were run in parallel. Immobilisation of daphnia magna occurred in a dose-response relationship; i.e. increasing immobilisation with increasing copper oxide concentration. The derived nominal EC50 for the submission substance was 732 mg/L (recalculated based on the ratio of MnO2 and CuO in the reaction mass), corrsponding to 0.3 mg/L dissolved copper (measured).

As copper oxide was the toxic constituent of the submission substance, the key value for the environmental hazard assessment of the reaction mass of copper oxide and manganese dioxide was based on the derived effect concentration of copper oxide.