Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
24 November 2016 to 24 April 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report date:
2017

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 111 (Hydrolysis as a Function of pH)
Qualifier:
according to guideline
Guideline:
EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Reference substance name:
3,3'-[ethylenebis[(3-sulpho-p-phenylene)azo]]bis[5-amino-4-hydroxynaphthalene-2,7-disulphonic] acid, compound with 2,2',2''-nitrilotriethanol (1:6)
Cas Number:
75701-36-9
IUPAC Name:
3,3'-[ethylenebis[(3-sulpho-p-phenylene)azo]]bis[5-amino-4-hydroxynaphthalene-2,7-disulphonic] acid, compound with 2,2',2''-nitrilotriethanol (1:6)
Test material form:
solid: granular
Radiolabelling:
no

Study design

Analytical monitoring:
yes
Details on sampling:
- Sampling time for parent: at 0, 24 and 120 hours in duplicate
- Sample storage conditions before analysis: no data

Duplicate aliquots (A and B) of each sample solution were diluted by a factor of 10 using acetonitrile: relevant buffer (1:9 v/v).
Buffers:
-pH 4
Citric acid 0.006 mol/dm3
Sodium chloride 0.004 mol/dm3
Sodium hydroxide 0.007 mol/dm3
pH 7
Disodium hydrogen orthophosphate (anhydrous) 0.003 mol/dm3
Potassium dihydrogen orthophosphate 0.002 mol/dm3
Sodium chloride 0.002 mol/dm3
pH 9
Disodium tetraborate 0.001 mol/dm3
Sodium chloride 0.002 mol/dm3
Details on test conditions:
Pre-test
- Measures taken to avoid photolytic effects: shielded from light
- Measures to exclude oxygen: ultrasonication and degassing with nitrogen
- Nominal cocnentration: 4.0 g/L
- Temperature: 50.0 ± 0.5 °C
Duration of testopen allclose all
Duration:
120 h
pH:
4
Temp.:
50 °C
Initial conc. measured:
>= 3.42 - <= 3.51 g/L
Duration:
120 h
pH:
7
Temp.:
50 °C
Initial conc. measured:
>= 4.02 - <= 4.03 g/L
Duration:
120 h
pH:
9
Temp.:
50 °C
Initial conc. measured:
3.98 g/L
Number of replicates:
2/pH
Positive controls:
no
Negative controls:
no
Statistical methods:
NA

Results and discussion

Preliminary study:
only a pre-liminary study was performed
Test performance:
The substance is stable at pH 4 (recovery after 5 days at 50°C: 102-106%), pH 7 (recovery after 5 days at 50°C: 111%) and pH 9 (recovery after 5 days at 50°C: 111%)
Transformation products:
not measured
Remarks:
the substance is hydrolytically stable
Dissipation DT50 of parent compound
Remarks on result:
hydrolytically stable based on preliminary test

Any other information on results incl. tables

 pH 4

Time (Hours)

 

Concentration (g/L)

 

% of mean initial

concentration

 

A

B

A

B

0

3.42

3.51

-

-

24

3.62

3.76

104

109

120

3.54

3.68

102

106

 

pH 7

Time (Hours)

 

Concentration (g/L)

 

% of mean initial

concentration

 

A

B

A

B

0

4.02

4.03

-

-

24

4.01

4.02

99.6

99.9

120

4.45

4.47

111

111

 

pH 9

Time (Hours)

 

Concentration (g/L)

 

% of mean initial

concentration

 

A

B

A

B

0

3.98

3.98

-

-

24

4.05

4.06

102

102

120

4.43

4.43

111

111

 

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Conclusions:
The substance is stable for > 1 year at pH 4, 7 and 9 at 25 °C
Executive summary:

In a preliminary hydrolysis study the substance was incubated at pH 4, 7 and 9 at 50 °C during 120 hours. The hydrolysis was less than 10% after 5 days at 50 °C, equivalent to a half-life greater

than 1 year at 25 °C