Pregnenolone

Boiling point

Administrative data

Endpoint:

boiling point

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is a solid which decomposes before boiling

Cross-reference

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 December 2017 - 08 February 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

2016

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

Version / remarks:

1998

Deviations:

no

GLP compliance:

yes

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

189.7 °C

Decomposition:

yes

Decomp. temp.:

325 °C

Key result

Melting / freezing pt.:

195.3 °C

Decomposition:

yes

Decomp. temp.:

325 °C

TGA EXPERIMENT (PRELIMINARY TEST)

Significant decrease of weight from 325°C upwards. 25% weight loss at 389°C and 70% weight loss at 424°C.

After the experiment, a light orange molten residue remained in the sample container (original colour: white). The change of the colour indicated reaction and/or decomposition of the test item.

DSC EXPERIMENT 1

Two endothermic peaks were observed between 175°C and 225°C followed by an endothermic effect starting at 325°C. The extrapolated onset temperature of the first peak was 189.718°C and the peak maximum of the second peak was 195.133°C. These endothermic effects were most likely obtained due to melting of the test item. The third endothermic effect was probably obtained due to reaction and/or decomposition of the test item. After the experiment, a light yellow molten residue remained in the sample container (original colour: white). The change of the colour indicated reaction and/or decomposition of the test item.

DSC EXPERIMENT 2

In order to investigate the melting peak, Experiment 2 was stopped directly after the second melting peak. The extrapolated onset temperature was of the first peak was 189.683°C and the peak maximum of the second peak was 195.480°C.  After the experiment, a white molten residue remained in the sample container. It demonstrated that melting was the reason for the endothermic effects.

DATA HANDLING

The first melting temperature was determined as the mean melting temperature of Experiment 1 (189.718°C) and Experiment 2 (189.683°C).

The second melting temperature was determined as the mean peak maximum of Experiment 1 (195.133°C) and Experiment 2 (195.480°C).

DSC curve recorded during heating: see Illustration

Conclusions:

The melting temperatures of the substance were determined to be 189.7°C and 195.3°C.

Executive summary:

Differential Scanning Calorimetry (DSC) experiments were performed in a GLP study according to EC A.1, OECD 102 and OPPTS 830.7200.

Two melting temperatures were determined for the substance in duplicate obtaining mean values of 189.7°C and 195.3°C.

Reaction and/or decomposition of the substance started at 325°C.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018