Phenoxazin-5-ium, 3,7-bis(diethylamino)-, formate (1:1)

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 04, 2017 - August 06, 2017

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:

3,7-bis(diethylamino)phenoxazin-5-ium nitrate

EC Number:

277-539-5

EC Name:

3,7-bis(diethylamino)phenoxazin-5-ium nitrate

Cas Number:

73570-52-2

Molecular formula:

C20H26N3O.NO3

IUPAC Name:

3,7-bis(diethylamino)phenoxazin-5-ium nitrate

Test material form:

solid

Results and discussion

Vapour pressure

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

< 0 Pa

Vapour pressure at 50°C (if relevant for classification of gas under pressure)

Key result

Vapour pressure:

< 0 Pa

Any other information on results incl. tables

Individual Results

The vapour pressure was measured in the temperature range of 30 °C to 100 °C. The measured vapour pressures at the corresponding temperatures are listed in Table 1. After the measurement a mass loss of approx. 6 % (w/w) was determined.

Table 1: Measured vapour pressures and corresponding temperatures

Temperature / °C	Vapour pressure / hPa
30	n.e.
40	1.2 × 10^-4
50	9.2 × 10^-6
60	2.4 × 10^-5
70	4.6 × 10^-5
80	4.9 × 10^-5
90	4.3 × 10^-5
100	4.4 × 10^-5

n.e.: not evaluable

The data point at 40 °C was attributed to low boiling contents like humidity. 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. 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 (constantB) for substances of high molecular weight, which can be derived from literature values (e.g. Handbook of Chemistry and Physics) are lower than -5000. Thus, for a conservative estimation of the vapour pressure of the test item at 20, 25 and 50 °C, a value of -5000 for constant B and a value of 273.15 for constant C, respectively, were used.

The data point with the highest vapour pressure of the measurement at 80 °C was used as the starting point for the calculation. The measured vapour pressure at 80 °C was 4.9× 10^-5 hPa.

Based on this assumption, the constantA of the Antoine equation was calculated .

Subsequently, the vapour pressure at 20, 25 and 50 °C can be calculated with the Antoine equation.

Table 2: Calculated vapour pressure at 20, 25 and 50 °C

T / °C	p / hPa	p / Pa
20	< 6.2×10^-8	< 6.2×10^-6
25	< 1.2×10^-7	< 1.2×10^-5
50	< 2.4× 10^-6	< 2.4× 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.

Table 3: Final upper limit values for the vapour pressure at 20, 25 and 50 °C

T / °C	p / hPa	p / Pa
20	< 1×10^-8	< 1×10^-6
25	< 1×10^-7	< 1×10^-5
50	< 1× 10^-6	< 1× 10^-4

 

Applicant's summary and conclusion

Executive summary:

Final results

The following vapour pressure values for the test item were extrapolated from the experimental data (vapour pressure balance):

Based on the measured vapour pressure at 80 °C (vapour pressure balance), the following upper limit vapour pressure values for the test item were calculated:

T / °C	p / hPa	p / Pa
20	< 1×10^-8	< 1×10^-6
25	< 1×10^-7	< 1×10^-5
50	< 1× 10^-6	< 1× 10^-4