TETRASODIUM ETHYLENE 1,1-DIPHOSPHONATE

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002-04-30 - 2002-07-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002-04-30 - 2002-07-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

GLP compliance:

yes (incl. QA statement)

Remarks:

2000-04-26

Type of method:

HPLC estimation method

Media:

soil

Specific details on test material used for the study:

- Synonyms: ITC 908, vinylidenephosphonic acid tetrasodium salt (VDPA tetrasodium salt)
- Lot/batch No.of test material: 562CH/646
- Purity: > 85%
- Storage condition of test material: Room temperature, in the dark

Type:

Koc

Value:

< 17.8 dimensionless

pH:

7

Type:

log Koc

Value:

< 1.25 dimensionless

pH:

7

Conclusions:

The adsorption coefficient (Koc) of the test material has been determined to be less than 17.8, log10 Koc < 1.25.

Executive summary:

The adsorption coefficient (Koc) of the test material has been determined to be less than 17.8, log10 Koc < 1.25.

Cross-reference 2

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

relative density

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002-04-30 - 2002-07-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

EU Method A.3 (Relative Density)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7300 (Density / Relative Density / Bulk Density)

GLP compliance:

yes (incl. QA statement)

Remarks:

2000-04-26

Type of method:

air comparison pycnometer (for solids)

Specific details on test material used for the study:

- Synonyms: ITC 908, vinylidenephosphonic acid tetrasodium salt (VDPA tetrasodium salt)
- Lot/batch No.of test material: 562CH/646
- Purity: 87.33%
- Storage condition of test material: Room temperature, in the dark

Key result

Type:

relative density

Density:

2.19

Temp.:

20.5 °C

A stainless steel ball of known volume was used to calibrate the instrument prior to measurement of the test sample.

Conclusions:

The relative density of the test material has been determined to be 2.19 at 20.5 +- 0.5 °C.

Executive summary:

The relative density of the test material has been determined to be 2.19 at 20.5 +- 0.5 °C.

Cross-reference 3

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

dissociation constant

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2002-04-30 - 2002-07-09

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

There are three possible methods for the determination of dissociation constant referenced in the OECD Guideline 112: Spectroscopic method, conductometric method and titration method.

The spectroscopic method has been shown to be of no use for this test material. There were no appreciable differences in spectra under strongly acidic and basic conditions. In any case, the test material absorbs UV light at only very low wavelengths where there was far too much interference from pH adjusting media (acid/base). Finally, this was expected for this material since there are no significant UV absorbing groups present in the test material such as aromatic rings for example.

The conductometric method was predicted to be of no use for this material since it has complex overlapping dissociation constants. Test material purity is only approximately 87% pure and hense, impurity influence would be high, especially since some impurities are salts as well, significantly contributing to conductivity readings.

The titration method has also been predicted to be of no use for this test material due to the purity issue. Additionally and more importantly however, the predicted dissociation constants of the test material overlap (refer to computer-based estimations). For this method (and the conductometric method) to work successfully, the dissociation constants should be ideally 2 units away from each other. The predicted values are only approximately 1.2 units apart and hence, on titration, certain ions will be in various states of ionization.

Finally, predominantly due to the overlapping dissociation constants and the above reasons, the dissociation constants of the test material are extremely complex and outside the range and scope of all the methods detailed in OECD Guideline 112.

As no experimental testing was deemed possible, it was therefore considered appropriate to estimate dissociation constants of the test material through computer-based estimation software and replacing sodium ions with protons. Estimation software used: Advanced Chemistry Development (ACD), pKa calculator, version 6.0

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

QSAR

GLP compliance:

yes (incl. QA statement)

Remarks:

2000-04-26

Specific details on test material used for the study:

- Synonyms: ITC 908, vinylidenephosphonic acid tetrasodium salt (VDPA tetrasodium salt)

Dissociating properties:

yes

No.:

#1

pKa:

7.19

Temp.:

25 °C

Remarks on result:

other:

Remarks:

Assumed temperature in the model

No.:

#2

pKa:

5.87

Temp.:

25 °C

Remarks on result:

other:

Remarks:

Assumed temperature in the model

No.:

#3

pKa:

1.14

Temp.:

25 °C

Remarks on result:

other:

Remarks:

Assumed temperature in the model

No.:

#4

pKa:

0.61

Temp.:

25 °C

Remarks on result:

other:

Remarks:

Assumed temperature in the model

Conclusions:

The test material was predicted to have four dissociation constants of 7.19 +- 0.30, 5.87 +- 0.30, 1.14 +- 0.10 and 0.61 +- 0.10.

Executive summary:

No determination of dissociation constant was carried out for the test material. The test material has complex overlapping dissociation constants and is unsuitable for use with the methods detailed in OECD Guideline 112. However, using specialist chemical estimation software (Advanced Chemistry Development (ACD), pKa calculator, version 6.0, obtained using ACD (I-Lab web services)) and replacing all sodium ions with protons, the test material was predicted to have four dissociation constants of 7.19 +- 0.30, 5.87 +- 0.30, 1.14 +- 0.10 and 0.61 +- 0.10.

Cross-reference 4

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002-04-30 - 2002-07-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions) - Method B: Fibre Length and Diameter Distributions

GLP compliance:

yes (incl. QA statement)

Remarks:

2000-04-26

Type of method:

cascade impaction

Type of particle tested:

primary particle

Type of distribution:

mass based distribution

Specific details on test material used for the study:

- Synonyms: ITC 908, vinylidenephosphonic acid tetrasodium salt (VDPA tetrasodium salt)
- Lot/batch No.of test material: 562CH/646
- Purity: 87.33%
- Storage condition of test material: Room temperature, in the dark

Remarks on result:

not determinable because of methodological limitations

Remarks:

Too few particles were of a size less than 10 µm to allow accurate assessment of mass median aerodynamic diameter.

No.:

#1

Size:

< 100 µm

Distribution:

79.8 %

No.:

#2

Size:

< 10 µm

Distribution:

2.38 %

Conclusions:

The results indicated that the proportion by mass of particles which, if inhaled, can be expected to achieve deposition throughout the respiratory tract is 2.38%.

Executive summary:

Proportion of test material having a particle size less than 100 µm: 79.8% (sieve)

Proportion of test material having a particle size less than 10 µm: 2.38% (cascade impactor)

The results indicated that the proportion by mass of particles which, if inhaled, can be expected to achieve deposition throughout the respiratory tract is 2.38%.

Cross-reference 5

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002-04-30 - 2002-07-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Deviations:

yes

Remarks:

The surface tension result was not corrected using the Harkins-Jordan correction table as the correction is not applicable to the apparatus used.

Principles of method if other than guideline:

The determination was carried out using a White Electrical Institute interfacial tension balance and a procedure based on the ISO 304 ring method. Once calibrated, the balance and ring assembly used in this test give a direct reading for surface tension that is within the required accuracy (+- 0.5 mN/m), this is a result of the reduced ring dimensions.
This deviation has been considered not to have affected the integrity of the study.

GLP compliance:

yes (incl. QA statement)

Remarks:

2000-04-26

Type of method:

ring method

Specific details on test material used for the study:

- Synonyms: ITC 908, vinylidenephosphonic acid tetrasodium salt (VDPA tetrasodium salt)
- Lot/batch No.of test material: 562CH/646
- Purity: 87.33%
- Storage condition of test material: Room temperature, in the dark

Surface tension:

71.9 mN/m

Temp.:

22 °C

Conc.:

1.02 g/L

Conclusions:

The surface tension of a 1.02 g/L solution of test material has been determined to be 71.9 mN/m at 22.0 +- 0.5 °C. The test material is considered not to be a surface-active material.

Executive summary:

The surface tension of a 1.02 g/L solution of test material has been determined to be 71.9 mN/m at 22.0 +- 0.5 °C. The test material is considered not to be a surface-active material.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.2110 (Hydrolysis as a Function of pH)

GLP compliance:

yes (incl. QA statement)

Remarks:

2000-04-26

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

443-520-7

EC Name:

-

Cas Number:

33016-77-2

Molecular formula:

C2H4Na4O6P2

IUPAC Name:

tetrasodium (1-phosphonatoethenyl)phosphonate

Test material form:

solid

Specific details on test material used for the study:

- Synonyms: ITC 908, vinylidenephosphonic acid tetrasodium salt (VDPA tetrasodium salt)
- Lot/batch No.of test material: 562CH/646
- Purity: 87.33%
- Storage condition of test material: Room temperature, in the dark

Study design

Analytical monitoring:

yes

Buffers:

pH 4; Potassium hydrogen phthalate; 0.05 mol dm-³
pH 7; Disodium hydrogen orthophosphate (anhydrous), Potassium dihydrogen orthophosphate, Sodium chloride; 0.03, 0.02 and 0.02 mol dm-³ respectively
pH 9; Disodium tetraborate, Sodium chloride; 0.01 and 0.02 mol dm-³ respectively

The buffer solutions were filtered through a 0.2 µm membrane filter to ensure they were sterile before commencement of the test. Also these solutions were subjected to ultrasonication and degassing with nitrogen to minimise dissolved oxygen content.

Duration of test

Duration:

5 d

Number of replicates:

2

Results and discussion

Preliminary study:

Sample solutions at pH 4, 7 and 9 were maintained at 50.0 °C for a period of 5 days.
Less than 10% hydrolysis was observed after 5 days at 50 °C, equivalent to a half-life greater than 1 year at 25 °C.

Test performance:

No second test performed based on the results of the preliminary study.

Transformation products:

not measured

Dissipation DT50 of parent compound

Dissipation DT50 of parent compound 1

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Dissipation DT50 of parent compound 2

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Dissipation DT50 of parent compound 3

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Any other information on results incl. tables

Duplicate standard solutions of test material were prepared in water:relevant buffer at a nominal concentration of 200 mg/L.

Applicant's summary and conclusion

Conclusions:

The estimated half-life at 25 °C of the test material is > 1 year for pH 4, 7 and 9.

Executive summary:

The estimated half-life at 25 °C of the test material is > 1 year for pH 4, 7 and 9.