Scale (coating), copper

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:

Scale (coating), copper

EC Number:

273-744-9

EC Name:

Scale (coating), copper

Cas Number:

69012-45-9

IUPAC Name:

scale (coating), copper

Details on test material:

B10, Scale, slag-type material from Cu melting furnace, primary smelter (representative, homogenized), sample code: slag from melting furnace, lab code: 09TT03840
B10, Scale, slag-type material from Cu rolling mill (representative, homogenized), sample code: scale coating from rolling mill, lab code: 09TT03897
B10, scale, dross-type (site 2, fines, homogenized), lab code: 10TT01448
B10, scale, dross-type (site 2, particles, homogenized), lab code: 10TT01449
B10, scale, dross-type (site 3) , lab code: 10TT01635
B10, scale, dross-type (site 3), lab code: 10TT01565

Results and discussion

Any other information on results incl. tables

Water solubility tests were done for samples 09TT03840 and 09TT03897. In the preliminary test,0.1277 g sample 09TT03840 was found to be soluble in 1 mL volume of water (48 h time).The preliminary test did not indicate any solubility for the sample 09TT03897.Approximately 6 g sample 09TT03840 and 21 ml water, and 5 g sample 09TT03897 and 100 ml water were taken to the test. Specific weighed amounts are given in Appendices A-B.

The shaking timewas for 14-16 days.After that each sample was equilibrated for 24 h time.Table5 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 /38,43/.

11 and 21 mg/l Na was dissolved from the samples 09TT03840 and 09TT03897, respectively. 17 mg/l Si was dissolved from the sample 09TT03840. Otherwise the samples were low-soluble. The standard method involves three tests, which is not enough for a statistical analysis.

  Water solubility test

Sample code       09TT03840 (fraction0.85-5.0mm)

 

Lab. work code 10004702/69

 

Preliminary test:

0.1277 g sample was found to be soluble in 1 mL volume of water (48 h time). 

 

Flask test:

Shaking time                  Sample mass             Volume of water       

14 days                           6.3074 g                                 21 mL 

15 days                           6.3249 g                                 21 mL 

16 days                           6.3138 g                                 21 mL 

 

Shaking at 30°C, 24 h equilibration at 20±0.5°C.

Water solubility test

Sample code       09TT03897

Lab. work code 10004702/63

 

Preliminary test:

0.1 g sample was not found to be soluble in the following volumes of water: 0.1 mL, 0.5 mL, 1 mL, 2 mL, 10 mL, 100 mL, 200 mL

 

Flask test:

Shaking time                  Sample mass             Volume of water       

14 days                           5.084 g                                   100 mL           

15 days                           5.013 g                                   100 mL           

16 days                           5.028 g                                   100 mL           

 

Shaking at 30°C, 24 h equilibration at 20±0.5°C.

 

Table5:Average water solubility calculated from the 14-16 days shaking tests.

	Sample code	09TT03840	09TT03897
		Average or range	Average or range
pH		9.22-9.37	6.88-7.20
ICP Ag	mg/l	-	<1
ICP Al	mg/l	<0.2	<0.2
ICP As	mg/l	<0.2	<0.2
ICP Ba	mg/l	4	<0.2
ICP Ca	mg/l	10	5.6
ICP Cd	mg/l	-	<0.1
ICP Co	mg/l	<0.1	<0.2
ICP Cr	mg/l	<0.1	<0.2
ICP Cu	mg/l	<8	0.8
ICP Fe	mg/l	<0.1	<0.2
ICP K	mg/l	<5	<5
ICP Mg	mg/l	0.4	0.6
ICP Mn	mg/l	<0.1	<0.2
ICP Na	mg/l	11	20.8
ICP Ni	mg/l	<0.2	<0.2
ICP P	mg/l	<0.5	-
ICP Pb	mg/l	<0.2	<0.2
ICP S	mg/l	0.8	0.7
ICP Sb	mg/l	-	<0.2
ICP Se	mg/l	-	<0.2
ICP Si	mg/l	17	2.6
ICP Sn	mg/l	<0.2	<0.2
ICP Te	mg/l	-	<0.2
ICP Ti	mg/l	<0.2	-
ICP Zn	mg/l	<0.2	<0.2

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): other: insoluble to poorly soluble in preliminary test
Preliminary test did not indicate poor to low 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 do 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 solubilities were reported in mg/l.

For this UVCB, preliminary result demonstrated that substance is poorly soluble in water. The preliminary result showing solubility of the sample from melting furnace was not confirmed in the additional tests. Major results from the additional flask test were: with a loading of 5 or 6g/100ml, and shaking over 14 -16 days, main constituents showed poor solubilities, with the exception of Na, K, Ca and Si (low), and Cu (poor to low). The pH ranged from 9.22 to 9.37, and 6.88 to 7.20.

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

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