p-benzoquinone

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01.03.2018 - 04.05.2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Version / remarks:

2006

Deviations:

no

GLP compliance:

no

Type of method:

effusion method: Knudsen cell

Test material

Test material information

Constituent 1

Reference substance name:

p-benzoquinone

EC Number:

203-405-2

EC Name:

p-benzoquinone

Cas Number:

106-51-4

Molecular formula:

C6H4O2

IUPAC Name:

1,4-benzoquinone

Test material form:

solid: particulate/powder

Results and discussion

Vapour pressure

Vapour pressure 1

Key result

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

3 Pa

Vapour pressure 2

Key result

Test no.:

#2

Temp.:

25 °C

Vapour pressure:

3.9 Pa

Vapour pressure 3

Key result

Test no.:

#3

Temp.:

50 °C

Vapour pressure:

12.3 Pa

Any other information on results incl. tables

Thermal Stability

In the temperature range of 115 °C – 125 °C the test item showed an endothermic effect, which can be assigned to the melting of the test item. An exothermic effect was observed in the temperature range of 230 °C – 280 °C with an decomposition energy of -1130 J/g. No further thermal effects could be observed up to the maximum test temperature of 300 °C.

Table 1:    Results of the DSC-measurement

No.	Sample weight / mg	Start / °C	Energy / J/g	Remark
PN15073	10.76	115 (endothermic) 230 (exothermic)	+150 -1130	Figure 2

Effusion method: Knudsen cell

The vapour pressure was measured in the temperature range of 30.4 °C to 50.7 °C. The measured vapour pressure values together with the measured temperatures are listed in Table 2:

Table 2:    Results of the Effusion method

No.	Temperature / °C	Vapour pressure / Pa
1	10.1	1.81
2	12.1	1.98
3	13.1	2.18
4	14.2	2.19
5	20.3	3.09

The measured vapour pressure is slightly outside the measuring range (10^-3to 1 Pa) of the Knudsen cell. Nevertheless, as the vapour pressure value above 1 Pa could be detected properly by the Knudsen cell, this value can be used for the evaluation.

From the measured data points of the vapour pressure curve the constants A and B of the Antoine Equation were derived by regression of the data points to A = 7.0301, B = -1919.24, C = 273.15.

The vapour pressure of the test itemp-Benzoquinonecalculated by interpolation and extrapolation of the measured vapour pressure curve for the temperatures 20 °C, 25 °C and 50 °C, according to Regulation EC No. 440/2008 Method A.4.Vapour Pressure and OECD Test Guideline 104 (2006) is shown in Table 3:

Table 3:    Calculated vapour pressure values for 20 °C, 25 °C and 50 °C

Temperature / °C	Vapour pressure / Pa
20	3.0
25	3.9
50	12.3

Applicant's summary and conclusion

Conclusions:

As determined by the effusion method the vapor pressure of p-benzoquinone at 20°C, 25°C and 50°C is 3,0 Pa, 3,9 Pa and 12,3 Pa, respectively.

Executive summary:

The vapour pressure of the test item p-Benzoquinone was calculated by interpolation and extrapolation of the measured vapour pressure curve for the temperatures 20 °C, 25 °C and 50 °C, according to Regulation EC No. 440/2008 Method A.4. Vapour Pressure and OECD Test Guideline 104 (2006).

Temperature / °C	Vapour pressure / Pa
20	3.0
25	3.9
50	12.3