cyproconazole (ISO); (2RS,3RS;2RS,3SR)-2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-1,2,4-triazol-1-yl)butan-2-ol

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 Jan 2000 to 06 Mar 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling Point)

Version / remarks:

Jul 1995

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling Temperature)

Version / remarks:

Dec1992

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7220 (Boiling Point / Boiling Range)

Version / remarks:

Aug 1996

GLP compliance:

yes

Type of method:

differential scanning calorimetry

Key result

Atm. press.:

99.3 kPa

Decomposition:

yes

Decomp. temp.:

299 °C

RESULTS

The following investigations of the boiling behaviour of the test substance were carried out.

- The first investigation, using a heating rate of 10.0 °C / minute and starting at 140.0 °C, was discontinued at 360 °C. At 250 °C there had been no change observed in the sample. At 310 °C the sample had become somewhat more yellow and gas bubbles were visible. At 360 °C the sample was aerated and, due to the many gas bubbles present, appeared cloudy.

- A second investigation was then performed, using a heating rate of 20.0 °C / minute and starting at 240.0 °C. At 370 °C the investigation was discontinued: a light yellow discoloration was observed along 'With the aeration and apparent cloudiness.

- A third investigation, which used a heating rate of 10.0 °C / minute and started at 200.0 °C was discontinued at 370 °C. A yellow discoloration was observed along with the typical aeration and apparent cloudiness.

- A fourth and final investigation was then carried out, using a heating rate of 10.0 °C/ min, starting at 240.0 °C. At 310 °C the first gas bubbles were visible. At 320 °C the sample appeared cloudy and aerated. This investigation was then discontinued.

These observations strongly suggested that the substance decomposed before the boiling point could be reached.

In order to interpret these observations with the test substance, additional investigations were performed using DSC.

Finally, a second control determination of the boiling point of toluene was then performed using the same conditions as before. A boiling point of 110.3 °C was again determined. Using the measured atmospheric pressure, 99.3 kPa, the temperature correction factors given in the OECD TG 103, the Sidney-Young number-value-equation, and the boiling point of toluene at standard pressure, it was possible to calculate the corrected boiling point, 109.9 °C, of toluene at the measured atmospheric pressure. The experimentally determined average boiling point of toluene, 110.3 °C, agreed with this calculated, corrected value.

In order to interpret the observations made, additional investigations were performed under GLP, using DSC, by the testing facility. A Perkin Elmer 7 Series Thermal Analysis System was used. The thermal behaviour of the test substance was investigated, not only in air, but also under a nitrogen atmosphere, using a heating rate of 10.0 °C/ minute and starting from 25.0 °C. Under nitrogen, decomposition was observed to commence at about 230 °C, becoming distinct at about 291 °C. In air, however, a weak oxidation occurred in the temperature range 115 °C to 279 °C, with a peak maximum at 233 °C. Subsequently, thermal decomposition commenced at about 299 °C. Therefore, the initial decomposition is oxidative in nature. In neither curve was any evidence of boiling observed.

Conclusions:

Due to the thermal decomposition of the test substance it was not possible to determine the boiling point under normal pressure. Thermal decomposition starts at 299 °C before boiling point is reached, and oxidative decomposition starts at about 115 °C .

Executive summary:

The boiling temperature of the test substance was assessed according to OECD TG 103, EC Method A.2 and EPA OPPTS Guideline 830.7220 and in compliance with GLP. The test substance started to decompose at 299 °C, before the boiling point is reached. In air, weak oxidative decomposition was observed to start at around 115 °C. Therefore, determination of the boiling point is not possible.

Description of key information

The test substance started to decomposed thermally at about 300 °C, prior to reaching the boiling. In air, weak oxidative decomposition started at around 115 °C. Hence, no boiling point could be determined. OECD TG 103, Das 2000.

Key value for chemical safety assessment

Temperature of decomposition (state purity):

299 °C