Copper

Additional information on environmental fate and behaviour

Administrative data

Endpoint:

additional information on environmental fate and behaviour

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Already discussed at the meeting od the competent authorities for Existing Substance regulations

Data source

Reference

Reference Type:

publication

Title:

Methodology for aquatic hazard classification of massive metal forms: the copper case

Author:

Rodriguez, P.H, Adams, W and Delbeke, K.

Year:

2007

Bibliographic source:

Proceeding of the sixth International Copper Conference, Copper 2007, Volume VI pp 217-228

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Annex 10 GHS

Principles of method if other than guideline:

Transformation/dissolution tests of copper massive materials were carried out at pH 6, 7 and 8, at loadings of respectively 1 and 100 mg/L. Different surface areas were tested. Abbrasion of the materials was observed and therefore additional tests were carried out using an anti-abrasion device (polypropyleen wheels added to the end of a copper wires).

GLP compliance:

no

Type of study / information:

The lab has participated to the OECD intercalibration exercise

Test material

Test material information

Constituent 1

Reference substance name:

Copper

EC Number:

231-159-6

EC Name:

Copper

Cas Number:

7440-50-8

Molecular formula:

Cu

IUPAC Name:

copper

Test material form:

other: copper wires

Details on test material:

copper wire pieces (99.9% purity) with varying diameters. The tests were carried out with various mass loadings (1-100 mg/l) and surface area loadings (1-281 mm2/l)

Results and discussion

Any other information on results incl. tables

Copper releases during the transformation/dissolution tests were dependent on the stirring rate. At high stirring rates(>50 rpm), copper release increases exponentially and high intra- and inter-vessel variability in measured dissolved copper concentrations were observed .  Considering that this increased release and variability was related to particle abrasion, and particle abrasion should be prevented (GHS rev. 4, 2011, Annex 10, A10.2.3.1) ,only release rates from tests at 50 rpm are retained.

Copper releases during transformation/dissolution tests are pH dependent and 6 times higher releases were measured at pH 6 compared to pH 7 and 8 

Copper releases during transformation/dissolution tests are related to the surface loading tested (mm²/l). The average surface–specific copper release (µg dissolved Cu /mm²exposed) for respectively 7 (acute) and 28 (chronic) dissolution/transformation tests at 50 rpm (with some abrasion) are:

·        1.15 µg Cu/ mm²after7 days T/D tests at pH 6

·        0.13 µg Cu/mm²after7 days T/D tests at pH 7

·        0.19 µg Cu/mm²after7 days T/D tests at pH 8.  

·        4.2 µg Cu/mm²after 28 days T/D test at pH 6 (excluding one outlier). 

 

The data result in 7 days transformation/dissolution of a massive particle of 1mm diameter, at pH 6 and a loading of 100 mg/L, of 77 µg Cu/L.

The data result in 28 days transformation/dissolution of a massive particle of 1mm diameter, at pH 6 and a loading of 1 mg/L, of 2.8 µg Cu/L.

The 7-days non-abrasive transformation/dissolution of a massive particle of 1mm diameter, at pH 6 and a loading of 100mg/L resulted in much lower total release of (6.7 µg Cu/L and 0.15 µg Cu/mm2). 

Applicant's summary and conclusion

Conclusions:

The results from the transformation/dissoluiton tests are key to the classification of copper massive materials.
The surface area approach allows to appy the surface-specific release rates to massive and powders with known surface area (mm2/g).

Executive summary:

Seven days transformation/dissolution tests were carried out at pH 6, 7 and 8, in accordance to the OECD guidelines (Annex 10 of GHS) using different surface loadings (1 -281 mm2/L). The results are applicable to derive the release of copper-ions from copper massives and copper particles with various specific surface area's (mm2/g).

- Abrasion of the materials was observed and therefore only realeases at 50 rpm were retained and some additional tests were carried out using an anti-abrasion device.

- Copper releases are dependent on the pH with highest release at pH 6

- Copper releases are linearly related to the exposured surface area.

The average surface–specific copper release (µg dissolved Cu /mm²exposed) for respectively 7 (acute) and 28 (chronic) dissolution/transformation tests are:

·        1.15 µg Cu/ mm²after7 days T/D tests at pH 6

·        0.13 µg Cu/mm²after7 days T/D tests at pH 7

·        0.19 µg Cu/mm²after7 days T/D tests at pH 8. 

- 4.2 µg Cu/mm²after 28 days T/D test at pH 6 (excluding one outlier).

The data result in 7 days transformation/dissolution of a massive particle of 1mm diameter, at pH 6 and a loading of 100 mg/L, of 77 µg Cu/L.

The data result in 28 days transformation/dissolution of a massive particle of 1mm diameter, at pH 6 and a loading of 1 mg/L of 2.8 µg Cu/L.

The 7-days non-abrasive transformation/dissolution of a massive particle of 1mm diameter, at pH 6 and a loading of 100mg/L resulted in much lower total release of (6.7 µg Cu/L and 0.15 µg Cu/mm2). 

The surface area approach allows to read across to other massive materials mass loadings and other surface loadings