Scale (coating), copper

Endpoint summary

Additional information

                                                                                                                                                        REACH Copper Consortium

 

 

Environmental classification of B10 Scale, copper

 

1.     Introduction and approach

 

The copper intermediate is identified as follows

 

Intermediate B10 - Scale (coating), Copper   “Residue produced by melting or treating at a high temperature metallic copper (metal, alloy, scrap). The intermediate consist mainly of copper metal and oxides from copper (I) or zinc. It may contain silicates.”
EC names	EC number/ EINECS No.	CAS No.
Scale (coating), copper*	273-744-9	69012-45-9
Waste solids, copper-refinery*	273-718-7	679012-18-6
Waste solids, copper-casting*	273-717-1	69012-17-5
Copper, dross*	305-408-5	94551-59-4
Scale (coating), mill, copper*	305-427-9	94551-81-2

 

Copper scale is considered as a complex metal bearing material.

For complex metal bearing substance, the self-classification of the UVCB substance (in accordance to the EU hazard classification system (CLP, 2009) was performed based on below outline:

 

Characterization: the material is accurately described from its elemental composition (typical concentrations and concentration ranges across production sites), and the specific speciation data (mineralogical information) obtained from representative samples. This information is enough to initiate the classification process.

Classification by the Mixture Approach

The UVCB is treated as a complex metal containing substance with a number of discrete constituting compounds (metals, metal compounds, non-metal inorganic compounds). The hazard classifications of each compound is then factored into a combined classification of the UVCB as a whole. For environmental endpoints, additivity and/or summation algorithms are applied to quantitatively estimate the mixture’s toxicity to aquatic organisms. These concepts and rules are incorporated in easy to use IT tools, which can be used to classify the UVCB (i.e. MeClas).

Bridging or Read-Across: (Eco)-toxicological data are not available for all the specific UVCBs being evaluated. Considering the knowledge and variability in composition, read-across and bridging is done by using  a "representative" mineralogical/speciation analysis  combined with the  "worst case" metal concentration (across companies)  as a basis for the classification of the UVCB substance (chemical and mineralogical surrogates with similar origin/production process and physical/chemical properties).

Eventual correction:correction for (bio)availability was made on basis of Transformation/dissolution test results available.

 

2.     Summary of the chemistry and metal releases

 

The chemistry and mineralogy of Scale, copper B10 intermediate was assessed by Liippo et al, 2010 (see IUCLID Section 1.4 Analytical information & Section 4.23). In this assessment, samples of scales corresponding to different types of materials were characterized. Samples were selected as representative for the production processes, and the origin of the raw material (e.g. scale coating and dross-like materials). Sampling and sample preparation was performed according to the “ECI sampling protocol REACH B10” (see IUCLID Section 1.4 Analytical information):  

Representative samples analysed:

• Type I: from cable producer 1: scale (coating)

• Type I: from cable producer 2 (=downstream user): copper scale

• Type II: from cable producer 1: slag as produced from a melting furnace (= dross)

• Type II: from cable producer 2 (downstream user): copper dross, from copper melting (a mix of copper dross and slags, with pieces up to 5cm diam)

• Type II: from (secondary) smelter: fines and parts were collected separately, resulting in two samples of copper dross (= two extremes); (sample 1) more oxidic fines, (sample 2) more metallic particulates

  

The studied six (6) copper scale and dross samples contains between 23.6 and 86.8% copper. Zinc and lead contents ranges from below detection limits to 19.1 and 1.6%, correspondingly. The chemistry and mineralogical data demonstrated that all tested samples correspond to the identity described above, although the mineralogical composition of the UVCB may vary slightly (see composition IUCLID Section 1.2). Most samples consist mainly of copper ( in some samples alloyed by zinc or aluminium), and copper oxides (cuprite and tenorite forms). Zincite (Zn oxides and Zn alloy) is present in two samples. In lead –bearing samples, lead is carried completely by metallic lead or mainly by metallic lead (61.5%), amorphous lead glass (32.1%) and lead oxides (6.3%).

 

For each type of scale, a characteristic distribution pattern for each constituting element was observed:

For type I (Scale-type materials):

Copper is in the form of Cu metal/alloys (massive, 46.09% from Total Cu) + oxides (WC Cu2O/Cu(I), 53.91% from total Cu)

Lead, if present, is in the form of Pb metal (massive, 100% from total Pb)

Iron, if present, is mainly in the form of amorphous glass

Other minor metal elements are, if present, following the same distribution pattern than Copper (= assumed Worst Case), i.e. metal/alloys (massive, 46.09% from Total Element) + oxides (WC , 53.91% from total Element)

 

For type II (Dross-type materials):

Copper is in the form of Cu metal/alloys (WC powder, 85.23% from Total Cu) + oxides (WC Cu2O/Cu(I), 14.77% from total Cu)

Lead is in the form of Pb metal/alloys (WC powder, 61.54% from Total Pb) + Pb compounds (38.46% from Total Pb)

Zinc is in the form of oxides (WC ZnO, 93.82% from total Zn) + metal/alloy (WC powder, 6.08% from Total Zn)

Nickel is in the form of oxides (WC NiO, 14.77% from total Ni) + Ni metal/alloy (WC powder, 85.23% from total Ni)

Iron is present mainly in the form of intermetallic inclusion, alloys, silicates, and/or amorphous glass.

Other minor metal elements are, if present, following the same distribution pattern than Cu , i.e. in the form of oxides (14.77% from total element) + metal/alloy forms (WC powder, 85.23% from Total element)

 

For classification purposes, these two distribution patterns were retained as Reasonable Worst Case (RWC). The two types of materials are mainly differentiated from each other based on their respective Fe content, closely linked to their Cu oxide content (i.e. higher % Fe( as in dross) = high %Cu metal/alloy forms and thus low %CuO content)

 

Considering the chemical compositions across industry, 4 grades were derived in order to cover the worst cases for key drivers of the classification:

 

	Grade 1	Grade 2	Grade 3	Grade 4
RWC pattern	Type I: scale(coating)-like materials	Type II : dross-like materials (Ni max <1%, Pb max <2%)	Type II : dross-like materials (Ni ≥1%, Pb max <2%)	Type II : dross-like materials  (Ni max <1%, Pb > 2%)
Cu	70 ≤ Cu < 90 % (typ: ca 75%)	20 ≤Cu ≤ 80% (typ: ca 70%)	20 ≤Cu ≤ 80% (typ: ca 70%)	20 ≤Cu ≤ 80% (typ: ca 70%)
Pb	Max ≤0.15%	Max < 2%	Max < 2%	Max < 10%
Ni	Max < 0.1%	Max < 1%	1 ≤ Ni < 10%	Max < 1%
Co	Max < 0.1 %	Max < 0.1%	Max < 0.1%	Max < 0.1%
Zn	Max ≤1%	Max < 40%	Max < 40%	Max < 40%
Cd	Max < 0.1%	Max < 0.1%	Max < 0.1%	Max < 0.1%
Sn	Max < 0.1%	Max < 10%	Max < 10%	Max < 10%
Fe	max ≤ca. 0.3%	Ca 0.1 ≤ Fe ≤ ca 15%	Ca 0.1 ≤ Fe ≤ ca 15%	Ca 0.1 ≤ Fe ≤ ca 15%
SiO2, Al2O3, etc	Max < 15%	Max < 30%	Max < 30%	Max < 30%

 

 

 

3.     Environmental classification

 

For complex metal bearing substance, for Lower Tier hazard classification in accordance to the EU hazard classification system (, 2009), the classification is based on the summation of classified components, as summarised in Table below.

Classification for acute hazards, based on summation of classified components

Sum of components classified as:	Mixture is classified as:
Acute Category 1´xM (a)≥25 %	Acute Category 1

 

For Higher Tier hazard classification in accordance to the EU hazard classification system (, 2009), ecotoxicity data obtained from tests carried out with soluble metal species and expressed as metal ions (µg Cu/L) are compared to metal ions released (µg Cu/L) during the transformation/dissolution (T/D) tests.  

 

Considering that the intermediate contains several metals, releases from a broad range of metals were assessed during T/D tests. The acute hazard assessment was subsequently assessed using the additive mixture toxicity rule.

Toxic Units (TU) were thus calculated for each sample, assuming additive metal toxicity as: 

TU =

A TU >1 indicates toxicity and may mead to classification

 

 

Whereby

- Ci corresponds to the respective metal concentrations measured after Transformation/dissolution of the material, in accordance to the OECD 2001. 

- L(E)C50i corresponds to the acute ecotoxicity reference values

 

The assessment ofacutehazard classification is based on a 7 days transformation/Dissolution test (T/D test) with 100 mg/l loading.

 

Considering the composition of this complex test material, the following experimental design was used:

-      The test was carried out at pH of 6, maximizing the releases of the relevant metal ions in the material (Cu, Pb, Ni).

-      For this massive to fine material, the test was therefore carried out at a particle size of below 1mm, in view to cover a worst-case sample of type I  

-      The tests were carried out at a maximum loading of 100 mg/L to enhance the reproducibility of the results for this complex material and to ensure that the metal releases are measurable (above detection limit).   

-      In view of deriving an acute classification endpoint, the test duration was set at 7 days.

-      Following the transformation/dissolution, a broad range of metals releases are considered.

 

The assessment of thechronichazard follows the same Toxic Unit approach. In this case, Ci corresponds to the metal releases after 28 days transformation/dissolution tests at pH 6 and a loading of 1 mg/L. Chronic releases (28 days, 1mg/L) were calculated by linear extrapolation from the 100mg/L loadings and 7 days tests.

 

The acute and chronic ecotoxicity data from the ARCHE database (i.e. MeClas) are used for the classification (Lower Tier and Higher Tier).

 

A worst case sample from Type I ((high Cu oxide content; D80 of 64µm and D50 of 29µm) was carried forward for Transformation/dissolution tests, performed by P. Rodriguez et al., 2010 (see IUCLID Section 5.6 Aditional information on environmental fate end behaviour). This worst-case sample, because of its granulometry and its high Cu oxide content can be considered also worst-case for type II material, except for Zn

The results from the chemistry (From Liipo et al, 2010) and transformation/dissolution tests (Rodriguez et al, 2010) are summarized in the table below

 

Table 1.Summary of metals released for the B10 sample after 7 days of transformation/dissolution test, 100 mg/L loading and pH 6. Metal releases were calculated as the difference between the mean sample release and the mean blanks release at 168 hours BDL= Below Detection Limit; SD= Standard Deviation

 

	CIMM, 2010		Outotec, 2010
Metal	T/D Metal release		Chemistry
	3897 Bulk		3897 Bulk	T/D Relative release	Reference values at pH6		calculated Toxic Units
					acute	chronic	acute	chronic
7 days – 100 mg/L	Mean	SD	%	In %
Copper, mg/L	978.80	78.55
			86.1	1.14%	25	20	39.2	2.0
Nickel, mg/L	BDL
Arsenic, mg/L	BDL
Lead, mg/L	1.63	0.33	0.04	4.08%	73.6	17.8	0.0	0.0
Zinc, mg/L	BDL		<0.004
Aluminium, mg/L	BDL						Conclusion
Cobalt,mg/L	BDL						acute	chronic
Molybdenum, mg/L	BDL
Barium, mg/L
Strontium, mg/L							Cat 2	Cat 2
Chromium,mg/L
Iron,mg/L
Manganese, mg/L
Selenium, mg/L
Cadmium, mg/L	BDL				SHAKER
Silver,mg/L					Copper Intermediate
Tellurium,mg/L					Contact method: orbital shaker 100 RPM
Tin,mg/L					target loading: 100 mg/L
Antimony,mg/L					pH 6
Silicon,mg/L					3897 (B10)

 

 

The soluble metals concentrations (T/D-100mg/L), were subsequently divided by the metal-specific acute ecotox reference values[1]. Acute Toxic Units (TU) were calculated for each sample, assuming additive metal toxicity (in accordance to theguidance for preparations) as described above. Relevant reference values for Copper and lead were known, the former being the major contribution to the toxicity.

 

From this assessment, the calculated toxic unit at a loading of 100 mg/L and pH 6 was for this sample was32 and may thus lead to an Acute 2 classification. 

 

For the Chronic classification, acute transformation/dissolution is to be assessed at a loading of 1 mg/L. The acute transformation/dissolution were therefore linearly extrapolated (to 28 days and 1 mg/L loading = divided by 100 and multiplied by 4) and compared to the chronic ecotox reference values¹. Considering that copper releases are linearly related to surface area, and time, (see reference Rodiguez et al, 2007), such linear extrapolation is considered as a good approximation. For Pb and Ni concentrations, the concentrations levels are very low (no saturation effect) and the concentrations level off as a function of time (likely passivation of the material) and therefore, this is expected to be a conservative approach.

 

Chronic Toxic Units (TU) were thus calculated for each sample, assuming additive metal toxicity as: 

TU = ∑ (soluble metal concentration / chronic reference NOEC value)

TU>1 indicate toxicity and lead to classification

 

The resulting toxic unit for this sample was 2 and consequently resulted in a (conservative) Chronic 2 classification.

 

In view to extrapolate the results to all scale samples across the industry, the relative releases of respectively Cu, and Pb were calculate as % metal released / % metal present (= potential release) at pH 6, during 7 days transformation/dissolution (see Table above). 

Extrapolation of these relative releases to the previously defined grade 1 (low Fe content, high Cu oxide content) with a max Cu content of 90 across industry (worst case per Grade 1, max across industry), resulted in the following environmental classifications: 

 

	Grade 1
without T/D	acute chronic 1
With T/D 7d	acute cat 2
with T/D 28d (regression)	chronic cat 2
	N; R51-53

 

The B10 sample carried forward to T/D did not contain Zn forms, therefore the extrapolation to Grade 2 was made on basis of relative releases from CuZn-alloys and ZnO as determined from T/D test made on similar materials such as copper (refining) slag and copper matte (see reference Liipo et al, 2010 for B2 and B8 copper intermediates). Additional T/D on type II materials with Zn is the forms of CuZn-alloys are likely to confirm the refined environment classification for Grade 2 demonstrating the contribution of other metals except copper is low and negligible. The same conclusion can be drawn for materials with high Nickel and high Pb, in which the mineralogical forms of comparable to those found in B10 copper scale type II (i.e. metal, alloy or glass inclusions). Because the major contribution to the aquatic Toxic Units calculation arise from Copper, the worst-case conclusion for Grade 1 can be extrapolated to Grade 2, 3 and 4, all of them containing Copper in similar mineral forms (i.e. metal + cuprite)

 

4.     Conclusion Environment   

 

	Grade 1	Grade 2	Grade 3	Grade 4
RWC pattern	Type I: scale(coating)-like materials	Type II : dross-like materials (Ni max <1%, Pb max <2%)	Type II : dross-like materials (Ni ≥1%, Pb max <2%)	Type II : dross-like materials  (Ni max <1%, Pb > 2%)
Cu	70 ≤ Cu < 90 % (typ: ca 75%)	20 ≤Cu ≤ 80% (typ: ca 70%)	20 ≤Cu ≤ 80% (typ: ca 70%)	20 ≤Cu ≤ 80% (typ: ca 70%)
Pb	Max ≤0.15%	Max < 2%	Max < 2%	Max < 10%
Ni	Max < 0.1%	Max < 1%	1 ≤ Ni < 10%	Max < 1%
Co	Max < 0.1 %	Max < 0.1%	Max < 0.1%	Max < 0.1%
Zn	Max ≤1%	Max < 40%	Max < 40%	Max < 40%
Cd	Max < 0.1%	Max < 0.1%	Max < 0.1%	Max < 0.1%
Sn	Max < 0.1%	Max < 10%	Max < 10%	Max < 10%
Fe	max ≤ca. 0.3%	Ca 0.1 ≤ Fe ≤ ca 15%	Ca 0.1 ≤ Fe ≤ ca 15%	Ca 0.1 ≤ Fe ≤ ca 15%
SiO2, Al2O3, etc	Max < 15%	Max < 30%	Max < 30%	Max < 30%
Aquatic CLP	Chronic 2 H411	Chronic 2 H411	Chronic 2 H411	Chronic 2 H411
Aquatic DSD	N; R51-53	N; R51-53	N; R51-53	N; R51-53

 

 

It is expected that additional Transformation/Dissolutions tests (7 and/or 28days) on a type II (dross-like material) would confirm the extrapolation from existing T/D test on B10 copper scale. Furthermore, the chronic classification could be removed based on existing test demonstrating removal of copper ions from the water column and strong binding of copper to sediments (ECI, , Classification and Labelling of Copper and Coated Copper Flakes under REACH and CLP, October 2010)

  

[1] Reference values at pH 6, from the Arche tool: Acute: 25 Cu µg /L; 73.6 µg Pb/L; 413 µg Zn/L;   120 µg Ni/L; Chronic: 20 µg Cu/L, 17.8 µg Pb/L and 82 µg Zn/L, 20 µg Ni/L.