cupro, copper processing

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: No GLP study but other quality assurance

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

GLP compliance:

no

Remarks:

other quality assurance

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

cupro, copper processing

EC Number:

919-583-6

IUPAC Name:

cupro, copper processing

Details on test material:

Representative samples collected according to Standard sampling protocol of the REACH Copper Consortium (see attach to Iuclid 1.4)
B15, sample description: Cupro, Representative charge, Metallic fraction (composite, grinded), sample code: MC_B15_54_1A_comp_0904, lab code: 09TT02932
B15, sample description: Cupro, Representative charge, metallic fraction (representative pieces, lumps), sample code: MC_B15_54_1B_comp_0904, lab code: 09TT02790
B15, sample description: Cupro, Representative charge, Oxidic fraction (ie powder) (composite, homogenized), sample code: MC_B15_54_2_comp_0904, lab code: 09TT02933
B15, sample description: Cupro, Al-specific charge, Metallic fraction (composite, grinded), sample code: MC_B15_Al_3A_comp_0906, lab code: 09TT05024
B15, sample description: Cupro, Al-specific charge, Metallic fraction (representative pieces, lumps), sample code: MC_B15_Al_3B_comp_0906, lab code:09TT04859

Results and discussion

Details on results:

42 mg/l Pb and 19 mg/l Ca were dissolved from the sample 09TT02933. Otherwise the samples were low soluble.

Any other information on results incl. tables

The preliminary test did not indicate any solubility for the studied samples. Approximately 5 g sample and 100 ml water were taken to each test. Specific weighed amounts are given in Appendices A-C of the study report.

The classical definition of water solubility is not applicable to multi-component i.e. complex substances. The usually accepted meaning of solubility in such cases was the composition of the aqueous solution formed at equilibrium under a defined set of conditions. It was however not always possible to establish that equilibrium of all components is achieved. Therefore, time and type of agitation of test vessels have been described (see 5.4).

The shaking time was for 09TT02790 and 09TT04859 14-16 days and for 09TT02933 13-15 days. After that each sample was equilibrated for 24 h time. Table 6 presents measured pH range and average metal concentrations for the samples. Substances with solubility <10 mg/l are considered low-soluble and those with solubility <1 mg/l are considered poorly soluble.

42 mg/l Pb and 19 mg/l Ca were dissolved from the sample 09TT02933. Otherwise the samples were low soluble. The standard method involves three tests, which is not enough for a statistical analysis.

 

Table 6: Average water solubility calculated from the 13-15 and 14-16 days shaking tests.

	Sample code	09TT02790	09TT02933	09TT04859
		Average or range	Average or range	Average or range
pH		8.67-9.48	10.40-10.85	5.79-8.89
ICP Ag	mg/l	<1	<1	<1
ICP Al	mg/l	<0.2	2	<0.2
ICP As	mg/l	<0.21	<0.2	<0.2
ICP Ca	mg/l	-	19	-
ICP Co	mg/l	<0.1	<0.2	<0.2
ICP Cr	mg/l	<0.1	<0.2	<0.1
ICP Cu	mg/l	<1	<0.2	<0.2
ICP Fe	mg/l	<0.2	<0.2	<1
ICP K	mg/l	<2	<5	<5
ICP Mg	mg/l	<0.2	<0.2	<0.1
ICP Mn	mg/l	<0.1	<0.2	<0.1
ICP Na	mg/l	<2	<3	<1
ICP Ni	mg/l	1.4	<0.2	1.6
ICP Pb	mg/l	<0.2	42	<0.5
ICP S	mg/l	<5	<5	<5
ICP Sb	mg/l	0.4	<0.2	<0.2
ICP Se	mg/l	<0.2	<0.2	<0.2
ICP Si	mg/l	5	0.4	4
ICP Sn	mg/l	<0.2	<0.2	<0.2
ICP Te	mg/l	<0.2	<0.2	<0.5
ICP Zn	mg/l	<0.5	-	<0.2

 

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): other: insoluble in preliminary test
Preliminary test did not indicate any solubility of the substance. Flask method test was performed on representative sample of the UVCB, a complex metal containing substance. Validity of the reported results confirmed by Harlan Lab (V. Gretton, 2010)

Executive summary:

Classic definition of solubility does not apply to the UVCB, who is a complex metal containing substance. The usually accepted meaning in that case is (according to ECHA Guidance on information requirements and chemical safety assessment Chapter R.7a) "the composition of the aqueous solution formed at equilibrium under a defined set of conditions". Temperature and the amount of substance added per unit volume of water (i.e. the loading) are the main factors to consider. It was not always possible to establish equilibrium of all components; therefore, time and type of agitation of the vessels have been described. Aqueous solubility was reported in mg/l.

For this UVCB, preliminary result demonstrated that substance is poorly soluble (i.e. insoluble) in water. Major results from the additional flask test were: approximately 5 g sample and 100 ml water were taken to each test; the shaking time was 14-16 days and/or 13-15 days, after that each sample was equilibrated for 24 h time. Under these conditions, solubility of the constituents remains low, except for Ca, K, Na, S, and Si (low to poor), as well as Ni and Pb (low). The pH of the solutions varied from 5.8 to 8.9, 8.7 to 9.5 and 10.4 to 10.8, respectively.

Under these conditions, the report acknowledges that stated solubility may be higher than reality for some samples (e.g. due to abrasion, difficult to remove tiny undissolved particles, etc)

The reported results from OECD 105 are therefore indicative for the behaviour of the UVCB in water. For the purpose of assessing environmental fate and behaviour of this difficult to test complex metal containing substance, Transformation/dissolution test would however be more appropriate.