Zirconium bis(hydrogen phosphate)

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study according OECD 111

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Zirconium bis(hydrogen phosphate)

EC Number:

237-401-7

EC Name:

Zirconium bis(hydrogen phosphate)

Cas Number:

13772-29-7

Molecular formula:

H3O4P.1/2Zr

IUPAC Name:

hydrogen phosphate;zirconium(4+)

Study design

Analytical monitoring:

yes

Details on sampling:

Inductively Coupled Plasma Atomic Emission was used to monitor the test substance.

Duration of test

Duration of test 1

Duration:

5 d

Temp.:

50 °C

Initial conc. measured:

< 0.1 other: ppm P

Duration of test 2

Duration:

5 d

Temp.:

50 °C

Initial conc. measured:

< 0.005 other: ppm Zr

Results and discussion

Preliminary study:

This test is designed to provide information on the concentration of ionic species produced in the environment when the substance undergoes either hydrolysis or degradation under conditions which render the substance soluble. The test is carried out at three pH conditions to simulate acidic, neutral and alkaline soil conditions and at elevated temperature conditions. The zirconium content and the phosphorus content of saturated solutions of the test substance were
monitored by Inductively Coupled Plasma Atomic Emission Spectrometry over a period of 1 week. The results of the test, expressed in parts per million of the elements, are presented in Table 1.
The detection limit ofthe instrument for zirconium was 0.005 ppm.
The results indicate that there was no appreciable solubility of the substance at the three pH values at the elevated test temperature of 50°C.
The slight increase in the zirconium concentration value of 0.005 ppm zirconium at pH 9.0 on the final day of test was not considererd to be significant in terms of solubiUty

Any other information on results incl. tables

Table 1: Results of the test, expressed in parts per million of the elements (detection limit = 0.005 ppm)

Time	pH 4.0		pH 7.0		pH 9.0
	Zr	P	Zr	P	Zr	P
Initial	<0.005	<0.1	<0.005	<0.1	<0.005	<0.1
Day 1	<0.005	<0.1	<0.005	<0.1	<0.005	<0.1
Day 2	<0.005	<0.1	<0.005	<0.1	<0.005	<0.1
Day 3	<0.005	<0.1	<0.005	<0.1	<0.005	<0.1
Day 4	<0.005	<0.1	<0.005	<0.1	<0.005	<0.1
Day 5	<0.005	<0.1	<0.005	<0.1	0.005	<0.1

Applicant's summary and conclusion

Conclusions:

Due to the low solubility of the test item hydrolysis of the test substance could not be detected.