Disodium 5,5'-[(1-methylethylidene)bis(4,1-phenyleneoxysulphonyl-2,1-phenyleneazo)]bis[6-aminonaphthalene-1-sulphonate]

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 November 2018 to 04 December 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Specific details on test material used for the study:

Test item: Acid Orange 94 Refined
Alternative name: Disodium 5, 5’-[(1-methylethylidene)bis(4,1-phenyleneoxysulphonyl-2,1-phenyleneazo)]bis[6-aminonaphthalene-1-sulphonate]
CAS number: 70161-18-1
EC number: 274-354-1
Intended use: Industrial chemical
Appearance: Reddish brown crystals
Storage conditions: Room temperature (10 – 30C), in the dark
Lot number: 8009
Expiry/Retest date: 31 December 2019
Purity: 97%

Key result

Water solubility:

>= 18 - <= 20 other: %w/w

Conc. based on:

test mat.

Incubation duration:

>= 24 - <= 72 h

Temp.:

20 °C

pH:

>= 6.4 - <= 6.5

4.6.3.1 Preliminary Test

The sample concentrations, observations and solution pH are shown in the following table:

Table 11

Sample	Concentration (% w/w)	Observations	Solution pH
1	5.25	Dark red liquid with no excess test item	6.6
2	10.3	Dark red liquid with no excess test item	6.5
3	20.2	Dark red immobile smooth paste	n/a
4	30.2	Dark red immobile smooth and textured paste	n/a
5	40.1	Dark red immobile textured paste	n/a
6	49.9	Dark red, wet granules of test item	n/a

Preliminary water solubility: In the range 10.3 to 20.2% w/w at 20.0 ± 0.5 °C.

4.6.3.2 Definitive Test

The sample concentrations, observations and solution pH are shown in the following table:

Table 12

Sample	Concentration (%w/w)	Observations	Solution pH
1	12.0	Dark red liquid with no excess test item	6.5
2	14.0	Dark red liquid with no excess test item	6.5
3	16.0	Dark red liquid with no excess test item	6.4
4	18.0	Dark red liquid with no excess test item	6.4
5	20.0	Dark red viscous paste	6.4

Water solubility: In the range 18.0 to 20.0% w/w at 20.0 ± 0.5 °C.

The standard EC A.6/OECD 105 methodology was considered not applicable to this test item due to the expected high saturation level. A range of sample concentrations were prepared to visually assess the point at which saturation was reached. Above the saturation level, the test item formed a paste from which removal of the excess test item would not have been possible.

Conclusions:

The water solubility of the test item has been determined to be in the range of 18.0 to 20.0% w/w at 20.0 ± 0.5 °C.

Executive summary:

The standard EC A.6/OECD 105 methodology, for the assessment of water solubility, was considered not to be applicable for this test item due to the expected high saturation level. A range of sample concentrations were prepared to visually assess the point at which saturation was reached. When the test item was above its saturation level, the test item formed a paste from which the removal of excess test item would not have been possible.

The water solubility of the test item has been determined to be in the range of 18.0 to 20.0% w/w at 20.0 ± 0.5 °C.

Description of key information

The standard EC A.6/OECD 105 methodology was considered not applicable to this test item due to the expected high saturation level. A range of sample concentrations were prepared to visually assess the point at which saturation was reached. Above the saturation level, the test item formed a paste from which removal of the excess test item would not have been possible.

The water solubility of the test item has been determined to be in the range of 18.0 to 20.0% w/w at 20.0 ± 0.5 °C.

Key value for chemical safety assessment

at the temperature of:

20 °C