[ethylenebis[nitrilobis(methylene)]]tetrakisphosphonic acid, calcium sodium salt

Phototransformation in water

Administrative data

Endpoint:

phototransformation in water

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Test procedure in accordance with national (draft) standard methods with acceptable restrictions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Materials and methods

Study type:

direct photolysis

Principles of method if other than guideline:

Method: other (measured)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

[ethane-1,2-diylbis[nitrilobis(methylene)]]tetrakisphosphonic acid

EC Number:

215-851-5

EC Name:

[ethane-1,2-diylbis[nitrilobis(methylene)]]tetrakisphosphonic acid

Cas Number:

1429-50-1

Molecular formula:

C6H20N2O12P4

IUPAC Name:

{ethane-1,2-diylbis[nitrilobis(methylene)]}tetrakis(phosphonic acid)

Study design

Light source:

sunlight

Sensitiser (for indirect photolysis)

Type of sensitiser:

water with additives

Results and discussion

Transformation products:

yes

Details on results:

12% transformation (phosphonate to orthophosphate) was measured after 17 days at pH 7 (9% at pH 4 and 4% at pH10). Levels of degradation in the presence of ferric (Fe III) nitrate were higher, with 82% transformation after 17 days at pH 7 (64% at pH 4 and 19% at pH10). The effect of other metals (chromic, zinc and cupric ions) was insignificant.

Any other information on results incl. tables

Table 1 presents the results seen for Dequest 2041 under the various conditions of this study.

Table 1: Degradation results for Dequest 2041

Test condition	pH	% transformation to orthophosphate
		Day 3	Day 9	Day 17
Light conditions	4	0	1	4
	7	1	6	11
	10	1	3	4
Dark conditions	4			1
	7			0
	10			0
With Ferric nitrate (light)	4	8	11	64
	7	7	45	56
	10	8	18	25
With Ferric nitrate (dark)	4			0
	7			0
	10			0
With Chromic nitrate (light)	4			4
	7			3
	10			6
With Chromic nitrate (dark)	4			1
	7			0
	10			1
With Zinc nitrate (light)	4			2
	7			5
	10			4
With Zinc nitrate (dark)	4			0
	7			0
	10			1
With Cupric nitrate (light)	4			1
	7			1
	10			4
With Cupric nitrate (dark)	4			0
	7			0
	10			1

Applicant's summary and conclusion

Validity criteria fulfilled:

not applicable

Conclusions:

Direct photolysis of EDTMP is not significant in the absence of sensitisers. Sensitised photolysis was observed in the presence of ferric nitrate.