Trisodium 2,4-diamino-3,5-bis-[4-(2-sulfonatoethoxy)sulfonyl)phenylazo]benzenesulfonate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27.11.96 to 07.02.97

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Principles of method if other than guideline:

In the preliminary test, a very good solubility in water and a very poor solubility in n-octanol were found indicating a partition coefficient below -2. Hence, a main test according to OECD Guidelines 107/117 (either HPLC or flask shaking method) could not be applied.

GLP compliance:

yes (incl. QA statement)

Remarks:

Switzerland GLP

Type of method:

other: estimated from its solubility in n-octanol and in water

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: WP2/96
- Expiration date of the lot/batch: November 30, 2004

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature at about 20 °C
- Stability under test conditions: ~ 50 g/l (20 °C)
- Solubility of the test substance in the solvent/vehicle: At least 48 h in water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

-5.4

Remarks on result:

other: calculated using the solubility in n-octanol and water respectively.

In the present study, the n-octanol solubility of FAT 45'176/A was determined to be < 1.131 pg/l, which is below the smallest calibration point. No peak was detected at the relevant retention time.

The water solubility of the test article was estimated to be about 570 g/l* in the pretest and was stated to be 330 g/l in the Test Report No. FC-96/1 OT.WS, CIBA-GEIGY Ltd., CH- 4002 Basel. The latter result was used for the calculation of the partition coefficient.

Thus, the partition coefficient, log Pow, of FAT 45'176/A was calculated to be

log Pow = log    1.313mg/l            = -5.4

                       330 • 1000 mg/l

Conclusions:

The partition coefficient, log PoW of FAT45'176/A was calculated from the individual solubilities in n-octanol and in water was -5.4.

Executive summary:

Neither the HPLC-method (OECD 117 Guideline) nor the flask-shaking method (OECD 107 Guideline) were applicable for the determination of the partition coefficient of FAT45'176/A. Thus, the log Pow-value for FAT 45176/A was estimated from its solubility in n-octanol and in water, respectively.

In conclusion, the partition coefficient, log Pow of FAT45'176/A was calculated from the individual solubilities in n-octanol and in water, respectively, to be -5.4.

Description of key information

log Pow of Reactive Orange 136 was -5.4.

Key value for chemical safety assessment

Log Kow (Log Pow):

-5.4

Additional information

Neither the HPLC-method (OECD 117 Guideline) nor the flask-shaking method (OECD 107 Guideline) were applicable for the determination of the partition coefficient of FAT45'176/A. Thus, the log Pow-value for FAT 45176/A was estimated from its solubility in n-octanol and in water, respectively.

In conclusion, the partition coefficient, log Pow of FAT45'176/A was calculated from the individual solubilities in n-octanol and in water, respectively, to be -5.4.