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Environmental fate & pathways

Phototransformation in water

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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

Constituent 1
Chemical structure
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.