2-(2-methoxyethoxy)ethyl 4-[(5-cyano-1-ethyl-1,6-dihydro-2-hydroxy-4-methyl-6-oxopyridin-3-yl)azo]benzoate

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 05, 2016 - October 07, 2016

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 guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

GLP compliance:

no

Type of method:

effusion method: by loss of weight or by trapping vaporisate

Test material

Test material information

Constituent 1

Reference substance name:

p-[(5-cyano-1,6-dihydro-2-hydroxy-1,4-dimethyl-6-oxo-3-pyridyl)azo]-N-(2-ethylhexyl)benzamide

EC Number:

250-205-6

EC Name:

p-[(5-cyano-1,6-dihydro-2-hydroxy-1,4-dimethyl-6-oxo-3-pyridyl)azo]-N-(2-ethylhexyl)benzamide

Cas Number:

30449-81-1

Molecular formula:

C23H29N5O3

IUPAC Name:

4-[(5-cyano-2-hydroxy-1,4-dimethyl-6-oxo-1,6-dihydropyridin-3-yl)diazenyl]-N-(2-ethylhexyl)benzamide

Test material form:

solid: particulate/powder

Results and discussion

Vapour pressure

Vapour pressure 1

Key result

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

< 0 Pa

Vapour pressure 2

Key result

Test no.:

#2

Temp.:

25 °C

Vapour pressure:

< 0 Pa

Any other information on results incl. tables

 Individual results

Vapour pressure balance

The vapour pressure was measured in the temperature range of 70 °C to 120 °C. The derived vapour pressures at the corresponding temperatures are listed in Table 1.

Table1: Measured vapour pressures and corresponding temperatures

Temperature / °C	Vapour pressure / hPa
70	7.8 × 10^-6
80	5.9 × 10^-6
90	7.1 × 10^-6
100	1.2 × 10^-5
110	1.3 × 10^-5
120	1.0 × 10^-5

Since the test did not yield vapour pressures sufficiently high to extrapolate to 20, 25 and 50 °C these values were estimated. According to the Antoine equation, the vapour pressure can be calculated.

For an extrapolation to lower temperatures a conservative assumption of the Antoine constant C is 273.15. This results in a linear dependency of log(p) of the inverse Temperature 1/T (in K). Values for the resulting slope of the Antoine equation (constant B) for similar substances (e.g. see report 20160366.03) have been estimated to be in the range of -2000. Thus, for a conservative estimation of the vapour pressure of the test item at 20, 25 and 50 °C, a value of -2000 for constant B and a value of 273.15 for constant C, respectively, were used.

The last data point of the measurement at 110 °C was used as the starting point for the calculation. The measured vapour pressure at 110 °C was 1.3× 10^-5 hPa.

Based on this assumption, the constant A of the Antoine equation was calculated. Subsequently, the vapour pressure at 20, 25 and 50 °C can be calculated with the Antoine equation.

Table2: Calculated vapour pressure at 20, 25 and 50 °C

T / °C	p / hPa	p / Pa
20	< 3.3×10^-7	< 3.3×10^-5
25	< 4.2×10^-7	< 4.2×10^-5
50	< 1.4× 10^-6	< 1.4× 10^-4

This is a conservative estimation of the vapour pressure of the test item for the listed temperatures. In order to further ensure a conservative approach the vapour pressures were rounded up to the next order of magnitude in order to obtain final upper limit values for the vapour pressure.

Table3: Final upper limit values for the vapour pressure at 20, 25 and 50 °C

T / °C	p / hPa	p / Pa
20	< 1×10^-6	< 1×10^-4
25	< 1×10^-6	< 1×10^-4
50	< 1× 10^-5	< 1× 10^-3

Applicant's summary and conclusion

Executive summary:

Based on the measured vapour pressure at 110 °C, the following upper limit vapour pressure values for the test item were calculated:

 

T / °C	p / hPa	p / Pa
20	< 1×10^-6	< 1×10^-4
25	< 1×10^-6	< 1×10^-4
50	< 1× 10^-5	< 1× 10^-3