Tetrasodium (1-hydroxyethylidene)bisphosphonate

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:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1979

Reference 2

Reference Type:

other company data

Title:

Unnamed

Materials and methods

Principles of method if other than guideline:

Photodegradation was measured for 17-day sunlight exposure to the phosphonate test substance in combination with specific metal ions in purified water.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Etidronic acid

EC Number:

220-552-8

EC Name:

Etidronic acid

Cas Number:

2809-21-4

Molecular formula:

C2H8O7P2

Test material form:

not specified

Study design

Light source:

sunlight

Sensitiser (for indirect photolysis)

Type of sensitiser:

water with additives

Details on sensitiser:

ferric, chromic, zinc and cupric nitrate salts

Results and discussion

% Degradation

% Degradation 1

% Degr.:

7

Sampling time:

17 d

Test condition:

pH 7; test material without sensitisers

Remarks on result:

other: equivalent dark control: 4% degradation

% Degradation 2

% Degr.:

78

Sampling time:

17 d

Test condition:

pH 7; test material with ferric nitrate. 55% degradation reached by day 3.

Remarks on result:

other: equivalent dark control: 2% degradation.

% Degradation 3

% Degr.:

70

Sampling time:

17 d

Test condition:

pH 7; test material with cupric nitrate. 55% degradation reached by day 3.

Remarks on result:

other: equivalent dark control: 37% degradation.

% Degradation 4

% Degr.:

6

Sampling time:

17 d

Test condition:

pH7; test material wtih zinc nitrate or with chromic nitrate.

Remarks on result:

other: equivalent dark control: 0% degradation (both sensitisers).

Transformation products:

yes

Any other information on results incl. tables

% Transformation (Phosphonate to Orthophosphate)

pH;  Day 3; Day 9; Day 17;

HEDP (Light)
 4; 16; 33; 44;
 7;  4;  5;  7;
10;  2;  2;  3;

HEDP (Dark)
 4;  -;  -;  3;
 7;  -;  -;  4;
10;  -;  -;  0;

HEDP/Ferric Nitrate
(Light)
 4; 60; 57; 55;
 7; 55; 75; 78;
10; 61; 76; 78;

HEDP/Ferric Nitrate
(Dark)
 4;   ;   ; 6;
 7;   ;   ; 2;
10;   ;   ; 1;

HEDP/Chromic Nitrate
(Light)
 4;  3;  7; 16;
 7;  2;  3;  6;
10;  2;  4;  6;

HEDP/Chromic Nitrate
(Dark)
 4;   ;   ; 0;
 7;   ;   ; 0;
10;   ;   ; 0;

HEDP/Zinc Nitrate
(Light)
 4; 11; 22; 41;
 7;  2;  4;  6;
10;  2;  4;  6;

HEDP/Zinc Nitrate
(Dark)
 4;   ;   ; 0;
 7;   ;   ; 0;
10;   ;   ; 0;

HEDP/Cupric Nitrate
(Light)
 4; 49; 62; 77;
 7; 55; 68; 70;
10; 62; 70; 67;

HEDP/Cupric Nitrate
(Dark)
 4;   ;   ; 10;
 7;   ;   ; 37;
10;   ;   ;  2;

Applicant's summary and conclusion

Conclusions:

Direct photolysis of Dequest 2001 is not significant.
Sensitised photolysis was observed in the presence of ferric
nitrate and cupric nitrate.