p-cymene

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2020-06-29 to 2020-07-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling Point)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling Temperature)

Version / remarks:

Regulation (EC) No 440/2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7220 (Boiling Point / Boiling Range)

Version / remarks:

1996

Deviations:

no

GLP compliance:

no

Type of method:

differential scanning calorimetry

Key result

Boiling pt.:

176 °C

Atm. press.:

1 013 hPa

Decomposition:

no

In the temperature range of 170 -190 °C an endothermic effect was observed.

Table 1:   Results of the DSC-measurements

Measurement No.	Sample weight / mg	Onset of Effect / °C	Range of effect / °C	Weight loss / mg	Atmospheric pressure/ hPa
PN19909	9.36	175.96	170 - 190 (endo)	9.36	1002.8
PN19912	9.47	175.12	170 - 190 (endo)	9.47	1002.6

During the heating phase a distinct endothermic effect was observed in the temperature range of 170 - 190 °C, which can be assigned to the boiling of the test item.

For the correction of the boiling temperature to standard pressure the test item was assigned to chemical group 2 (e.g. Hydrocarbons). According to appendix 8.2 a correction value ϕ = 4.9 was used for the temperature range from 170 °C to 190 °C.

The lowest measured onset temperature is corrected to normal pressure to be 175.54 °C and the highest onset temperature to be 176.37 °C. As the corrected onset temperatures in both tests do not deviate by more than 0.5 K from their mean value of 175.96 °C, this temperature can be used as boiling point. The test item has a boiling point of 176.0 °C.

No further thermal effects were observed up to the test end temperature of 500 °C.

Conclusions:

The test item has a boiling point of 176.0 °C at normal pressure (1013 hPa) as determined by Differential Scanning Calorimetry.

Executive summary:

A study was conducted according to OECD TG 103, Regulation (EC) No 440/2008 method A.2 and EPA OPPTS 830.7220 to determine the boiling point of the test item using differential scanning calorimetry. The test item was weighed out into an aluminium crucible under air. Two tests with about 9 mg of the test item were performed. As reference crucible, an empty aluminium crucible was used. The substance is a liquid at ambient conditions. Therefore, the tests were started at ambient temperature. The temperature was then increased up to 500 °C at a constant heating rate of 10 K/min under air. In the temperature range of 170 - 190 °C an endothermic effect was observed. The correction of the boiling temperature to standard pressure was performed according to H.N. Hass and R.F. Newton. The test item boiling point was determined to be 176 °C. No further thermal effects were observed up to the maximum test temperature of 500 °C.

Description of key information

The test item has a boiling point of 176.0 °C at normal pressure (1013 hPa) as determined by Differential Scanning Calorimetry.

Key value for chemical safety assessment

Boiling point at 101 325 Pa:

176 °C

Additional information

A study was conducted according to OECD TG 103, Regulation (EC) No 440/2008 method A.2 and EPA OPPTS 830.7220 to determine the boiling point of the test item using differential scanning calorimetry. The test item was weighed out into an aluminium crucible under air. Two tests with about 9 mg of the test item were performed. As reference crucible, an empty aluminium crucible was used. The substance is a liquid at ambient conditions. Therefore, the tests were started at ambient temperature. The temperature was then increased up to 500 °C at a constant heating rate of 10 K/min under air. In the temperature range of 170 - 190 °C an endothermic effect was observed. The correction of the boiling temperature to standard pressure was performed according to H.N. Hass and R.F. Newton. The test item boiling point was determined to be 176 °C. No further thermal effects were observed up to the maximum test temperature of 500 °C.