Sodium bis[3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-4-hydroxybenzene-1-sulphonamidato(2-)]chromate(1-)

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

May 23, 2014

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

QSAR estimation

Principles of method if other than guideline:

QSAR evaluation

GLP compliance:

no

Type of method:

other: QSAR evaluation

Test no.:

#1

Remarks on result:

other: QSAR estimation

Transition / decomposition:

yes

Remarks on result:

not measured/tested

The estimated value of Vp is 3.85 x 10^-33 Pa at 25°C.

Conclusions:

The value of vapour pressure estimated by EPI suite 4.1 is 3.85 x 10^-33 Pa at 25 °C

Executive summary:

Method

The QSAR prediction has been made with Epiwin 4.1 with Mpbpwin application.

Result

Vp= 3.85 x 10^-33 Pa at 25°C and 101325 Pa

Description of key information

3.85 x 10-33 Pa at 25 °C and 101325 Pa

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

25 °C

Additional information

Based on the OECD Guideline 104, the calculated values of the vapour pressure can be used:

- for deciding which of the experimental methods is appropriate,

- for providing an estimate or limit value in cases where the experimental method cannot be applied due to technical reasons (including where the vapour pressure is very low, e.g., less than 10^-3 Pa).

 

The estimation method proposed by the OECD 104 is the modified Watson correlation, for which the only experimental data required is the normal boiling point.

During the DSC analysis between 134 -164 °C (onset at 150.24 °C; enthalpy = -26.9 J/g) was observed a first endothermic peak, between 203 - 256 °C (onset at 212.98 °C; enthalpy = -34.12 J/g), a second endothermic peak followed by a degradation starting at 290 °C.

Considering that no evaluation was possible regarding the melting point, the evaluation of vapour pressure was however conducted: the modified Watson correlation cannot be used because no boiling point was recorded. Nevertheless a prediction made by Epiwin 4.1 of the US EPA by a Modified Grain method has been conducted and the vapour resulted: 3.85 x 10^-33, at 25 °C.

The smile notation used for estimation is: NS(=O)(=O)c7ccc(O[Cr]3Oc4ccc(cc4N=Nc2c(nn(c1ccccc1)c2C)O3)S(N)(=O)=O)c(/N=N/c5c(C)n(nc5O[Na])c6ccccc6)c7.

 

The predicted value of vapour pressure is out of the recommended range of the pressures of the methods reported in the OECD Guideline (10^-5 – 10^5 Pa), therefore the calculated value has been reported as key value for the Chemical Safety Assessment.