Trisodium 5-[[4-chloro-6-(ethylphenylamino)-1,3,5-triazin-2-yl]amino]-4-hydroxy-3-[(4-methyl-2-sulphonatophenyl)azo]naphthalene-2,7-disulphonate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

calculation (if not (Q)SAR)

Remarks:

estimated by calculation

Adequacy of study:

key study

Study period:

23.11.-28.11.2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

yes

Remarks:

See Any other information.....

GLP compliance:

yes (incl. QA statement)

Type of method:

shake-flask method to: flask method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

-2

Temp.:

23 °C

Remarks on result:

other: Educated guess

Estimation of partition coefficient

Based on this information the following Expert Statement is issued instead:

Educated guess of partition coefficient (log Pow) of the test substance, Reactive Red 45:1, is lower than -2.0 . 

Educated guess of partition coefficient (log Pow) of the test substance is based on knowledge and experience from previous studies of similar substances.      

Conclusions:

Educated guess of Partition coefficient (log Pow) of the test substance, Reactive Red 45:1 is: log Pow is lower than -2.0

Executive summary:

In previous study for the determination of Pow the the concentrations of test substancein octanol phases were calculated as difference from the original concentrations and the amount determined in the aqueous phases due to low solubility of Reactive Red 45:1 in octanol.

Based on the new findings from other studies of similar substances, it was considered that the procedure used for determination of the partition coefficient mentioned above was not appropriate and could give unreliable results.

 

Alternatively the partition coefficient could be estimated on the base of the water solubility and on the base of solubility in octanol.

 

The test substance is practically insoluble in n-octanol. Solubility of test substance in saturated n-octanol is under the limit of quantification – LOQ = 0.156 mg/L.

Thus the determination of partition coefficient n-octanol/water cannot be performed due to character of the test substance, Reactive Red 45:1.

Based on this information the following Expert Statement is issued instead:

Educated guess of Partition coefficient (log Pow) of the test substance Reactive Red 45:1 is lower than -2.0 .

Description of key information

The determination of the partition coefficient n-octanol/water cannot be performed due to the character of the test substance, Reactive Red 45:1.  An Expert statement was provided.

Key value for chemical safety assessment

Log Kow (Log Pow):

-2

at the temperature of:

23 °C

Additional information

Based on the findings from other studies of similar substances, it was considered that the procedure used for determination of the partition coefficient was not appropriate and could give unreliable results. Alternatively, the partition coefficient could be estimated on the basis of the water solubility and on the basis of the solubility in octanol. The test substance is practically insoluble in n-octanol. Solubility of test substance in saturated n-octanol is under the limit of quantification – LOQ = 0.5 mg/L.

Thus the determination of partition coefficient n-octanol/water cannot be performed due to character of the test substance, Reactive Red 45:1. 

Based on this information the following Expert Statement is issued instead: Educated guess of Partition coefficient (log Pow) of the test substance Reactive Red 45:1 is lower than -2.0.